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					             Association of Paediatric Anaesthetists of Great
                            Britain and Ireland
                             34th Annual Scientific Meeting
                                 9th & 10th March 2007
                       Manchester International Convention Centre
The local organising committee for APA Manchester 2007 welcomes you to Manchester for this,
the Association of Paediatric Anaesthetists 34th Annual Scientific Meeting & AGM. The Annual
Scientific Meeting takes place in the Manchester International Convention Centre, a purpose
built venue in the heart of Manchester.

The Annual Scientific Meeting on Friday and Saturday 9/10th March will take place in
the main Auditorium. This comprises the usual mix of free papers, invited lectures,
debate and posters. On Friday afternoon members are encouraged to attend the Annual
General Meeting which will take place in the Auditorium.

During the last session on Friday afternoon the APA awards and Honorary
Memberships will be present. This will be followed by the 6th Jackson Rees lecture. This year
we are privileged to be able to invite Baroness Susan Greenfield CBE, Professor of Synaptic
Pharmacology, University of Oxford to deliver this lecture. The title of this years lecture is What
is Conciousness?

The first session on Saturday morning comprises a mini-symposium on Technology in Paediatric
anaesthesia. The final session of the meeting should prove to be very interesting as our
International Expert Panel will present one of their most challenging cases. This will be
followed by Ask the Experts. The chairman for this session will pick 4 interesting or
controversial case scenario submitted by the membership online for our experts to answer.

We hope that this varied programme will provide something for everybody. We
welcome your feedback as this will help inform the APA Scientific Sub-Committee in
their planning for future meetings. So please fill in your feedback questionnaires and
leave them at the Registration desk before leaving.

We do hope that you enjoy your stay in Manchester and that our meeting proves to be
educational and enjoyable.

APA Manchester 2007 Local Organising Committee
Davandra Patel
Henrik Hack
Ralph Mackinnon
George Meakin
Lynne Meakin
Tanya Howell
Christine Taylor
Registration
Registration is located in the entrance foyer of the MICC. This will be open as follows:
Thursday 4th May 08.00 17.30
Friday 5th May 08.00 17.30
Saturday 6th May 08.15 13.30

Speakers and Speaker Preview
All speakers will have received final instructions in the week prior to the meeting. Please take
time to ensure that your presentation has been loaded onto the session hard disc and that
there are no technical difficulties. Please arrive in good time for your session and make
yourself known to the chair for that session. Remember the chairman will be searching you
out as well. If in doubt sit in the front row of the auditorium as this will be reserved for
speakers.

Speaker Preview will be located in the lower foyer of the Assembly Room. Technicians will be
available to assist you from 08.15 on Thursday morning and throughout the conference.
However please appreciate that loading of presentations will be most easily accomplished prior
to the start of each day, during breaks and at lunch time and not while sessions are in
progress. Please note that there will be no speaker preview room available on Saturday.

Catering arrangements
Coffee, lunch and tea will be served in the Great Northern Hall.

Trade Exhibition
This will be in the Great Northern Hall where refreshments are served. We urge you to take
the opportunity to visit the various trade stands as their presence does help to facilitate the
meeting.

Left Luggage
Facilities will be made available in the MICC to store luggage on Saturday morning. Please
enquire at Registration.


Social Programme
Opening Reception and Dinner
Thursday 8th March 19.30
The Lowry Art and Entertainment Centre, Salford Quays, home of the largest public collection of
LS Lowrys work. Delegates will be able to view the exhibits and then enjoy dinner at 20.30

The President of the APA will host the opening reception and dinner. This year the APA would
like to honour the Past Presidents by inviting them to the Thursday dinner as our guests.
Hopefully many of the past presidents will be able to attend this function.

The Lowry art and entertainment centre is      located in Salford Quays some 2-3 miles from the
MICC and conference hotels. There will         be coaches to and from the conference hotels.
Coaches will depart at 19.00 from outside       the GMEX- MICC. Details of coach timings will be
displayed at Registration.
Please take note of the 19.30 start time for   this evenings programme.

Association of Paediatric Anaesthetists Annual Dinner
Friday 9th March 19.00
The Great Hall, Manchester Town Hall

There will be a civic reception hosted by the Lord Mayor of Manchester followed by the annual
dinner at 20.00. A drinks reception will take place in the Banqueting and Reception rooms
followed by dinner in the grand surroundings of the Great Hall
Dinner will be followed with dancing to the Rhythm & Blues and Light Rock of the EYE CONZ
The seating plan for dinner will be displayed at registration during Friday afternoon.
Please take note of the 19.00 start time for this evenings programme.


Accompanying Persons Programme
Hosted by Mrs Lynne Meakin

Friday 9th March

       09.30          Pick up from the Midland Hotel
                      Tour of the Hat Works Museum in Stockport
                      Lunch at the Bridge Inn in Prestbury
                      Visit to Gawsworth village
                      Tea at Capesthorne Hall
                      Alderley Edge viewing point
       17.00          Return to the Midland and other conference hotels


Saturday 10th March

       09.30          Pick up from the Midland Hotel
                      Walking Tour of Manchester
                      Morning coffee
                      Visit to the Manchester Museum
       13.30          Return to the convention centre for lunch
                   ANNUAL SCIENTIFIC MEETING
                         Friday 9th May 2007

                                SESSION 1
                               08.55 - 10.30

                Chair: Dr Peter Crean, President of APA


08.55 - 09.00       Introduction and Welcome

09.00 - 09.30       Invited Lecture
                    Postoperative Nausea and Vomiting
                    Dr Alison Carr
                    Plymouth

09.30 - 10.30       Free papers
09.30 - 09.45       The effect of age on spontaneous breathing using propofol and
                    Remifentanil in children
                    N. Barker, S. Malherbe and J.M. Ansermino
                    Department of Anaesthesia, British Columbias Childrens
                    Hospital, Vancouver, Canada

09.45 - 10.00       Paediatric Total Intravenous Anaesthetic use: a nationwide study
                    Hill M, Peat W, Courtman S
                    Derriford Hospital, Plymouth, Devon

10.00 - 10.15       The effect of videotaped preoperative information on parental
                    anxiety during anaesthetic induction for elective paediatric
                    procedures
                    A.M. McEwen, C. Moorthy, C. Quantock, H. Rose
                    R.J. the Royal Alexandra Hospital for Sick Children

10.15 - 10.30       A comparison of the Laryngeal mask airway and oropharyngeal
                    for manual ventilation by critical care nurses in children
                    JA Rechner, VJ Loach, MT Ali, VS Barber, JD Young, DGMason
                    Nuffield Department of Anaesthetics, University of Oxford, John
                    Radcliffe Hospital, Oxford


10.45 - 11.15       Coffee, Trade & Posters
                          POSTOPERATIVE VOMITING IN CHILDREN

Dr Alison Carr
Derriford Hospital, Plymouth, UK

In this session, I report on the findings of the Postoperative Vomiting (POV) Guidelines Group
established for the Association of Paediatric Anaesthetists.

Members are: Alison Carr (Chair), Simon Courtman (Plymouth), Liam Brennan (Cambridge), David
Baines (Westmead, Australia), Helen Holtby (Toronto), Per-Arne Lonnqvist (Sweden), Jackie Pope
(Pharmacist, Plymouth).

Introduction
POV in children is common with an incidence of 13-42% in all children. 1,2 The number of
episodes of POV experienced by a child is also important.3 It is one of the leading causes of
parental dissatisfaction after surgery and is the leading cause of unanticipated hospital
admission following ambulatory surgery with resulting increased health care costs 4,5

Using SIGN methodology6, we are investigating:
1. Which children are at high risk of PONV? Which surgical procedures are at high risk of
   producing POV?
2. What anti emetics are effective in children?
3. What prophylactic anti emetic(s) should be used and when?
4. What is the treatment for established PONV in children and when?

Factors affecting POV in Children
Many factors affect the incidence of PONV in children: age, previous history of POV, gender,
preoperative anxiety, obesity and smoking. Risk of POV increases markedly over 3 years old
and continues to rise through early childhood into adolescence. A previous history of POV is an
independent risk factor of subsequent POV in children. Post-pubertal girls have an increased
incidence of POV which may be sex hormone related although the phase of the menstrual
cycle does not appear to affect the incidence.

Type and duration of surgery affect POV in children. High incidences of POV in children occur
after adenotonsillectomy and strabismus surgery and much of the published literature focuses
on POV after these types of surgery. Other types of surgery associated with an increase in
POV are otoplasty and groin surgery (herniotomy and orchidopexy) although the evidence is
less compelling.

Anaesthesia factors affect POV incidence. Use of volatile anaesthetic agents is associated with
increased risk of emesis particularly in children who have other risk factors for POV. The use of
nitrous oxide does not appear to be associated with a high risk of POV in children. Use of
opioids may be associated with increased risk of POV particularly if longer-acting agents are
used in the postoperative period.

Who should receive prophylaxis against POV?
Children with a past history of POV should be considered for prophylactic antiemetic
medication. Children scheduled for adenotonsillectomy or strabismus surgery should receive
prophylactic antiemetics. Troublesome POV is rare in infancy and children in this age group
rarely require prophylactic antiemetic medication.

The evidence that procedures other than strabismus surgery and adenotonsillectomy are
associated with a high incidence of POV is less compelling. However, when the consequences
of POV may significantly affect clinical outcomes e.g. result in admission after day-case surgery,
consideration should be given to using prophylactic antiemetics. Minimising POV is essential for
a successful day-case tonsillectomy programme.

What prophylaxis is effective for POV in children?
A 5HT3 antagonist, such as ondansetron, should be considered as a first line treatment in
children with a high risk of POV.7 Ondansetron can be used as a single agent to prevent early
and late POV, the oral route being as effective as using the intravenous route. Ondansetron
also seems to be equally effective to dexamethasone although the latter may be more effective
in reducing late POV. Children at increased risk of POV should be given prophylactically
ondansetron 0.10 to 0.15 mg.kg-1. There is currently no evidence to demonstrate a benefit of
timing of ondansetron administration in children.

Dexamethasone given alone reduces the risk of POV in children.8 It appears to be particularly
effective in preventing late POV (beyond the first 6 hours). A dose of 0.15 mg.kg-1 provides
good reduction in POV with no adverse effects. Currently the most effective dose of
dexamethasone for preventing POV in children is unknown. Doses of 0.1-1 mg.kg-1
dexamethasone (maximum dose 25mg) have been used for prevention of POV in children.9 A
dose ranging study ( 0.25 to 1.0 mg.kg-1 ) in 168 children under going strabismus surgery
compared to placebo could identify no benefit where doses greater than 0.25 mg.kg-1 were
used.10

Combination therapy with a second agent may improve the efficacy of ondansetron. In children
at high risk of POV, such as children scheduled for adenotonsillectomy or strabismus surgery,
combination therapy with dexamethasone should be considered. Ondansetron combined with
dexamethasone increases the effectiveness in preventing POV in children.11 Ondansetron when
combined with droperidol or metoclopramide was more effective in preventing POV than
ondansetron alone.12 It is recommended that combination therapy be used in children at high
risk of POV or where single agent therapy has failed before.

There is little support in the literature for the use of metoclopramide as an anti-emetic in
children for the prophylaxis of post-operative vomiting in the doses tested (usually 0.25mg/kg).

A variety of different non-pharmacological options have been described to prevent or treat POV
in children but the number of publications as well as number of children studied and study
design are often insufficient to allow for a meta-analysis or structured review. There is evidence
on the effect of different types of stimulation of the P6 acupuncture point (acupuncture,
acupressure, or electrical/laser stimulation) on POV in children.
The current evidence base supports the concept that acustimulation reduces PONV when
compared to the non-active control situation. Acustimulation appears to be equally effective in
preventing POV when compared with anti-emetic drugs in children. Thus, acustimulation may
be considered an alternative to anti-emetic prophylaxis in children undergoing surgery known to
be associated with a high risk of POV.
1.    Br J Anaesth 1992; 69(suppl 1): 24S-32S
2.    Br J Anaesth 1999; 83(1): 104-117
3.    Paed Anaesth 1997; 7: 125-9
4.    J Clin Anesth 1998; 10: 482-487
5.    Anesthesiology 1988; 69: 1009-1012
6.    http://www.sign.ac.uk
7.    Anesthesia & Analgesia 1999;88(6):1370-9.
8.    Anesthesia & Analgesia 2000;90(1):186-194
9.    Laryngoscope 2001; 111: 1712-8
10.   Anesthesia & Analgesia 2005; 100(6):1622-6
11.   Paediatric Anaesthesia 2001; 11(5):591-595
12.   Can J Anaesth. 2004 Apr;51(4):311-9
13.   Explore (NY) 2006; 2: 314-320
     THE EFFECT OF AGE ON SPONTANEOUS BREATHING USING PROPOFOL AND
                         REMIFENTANIL IN CHILDREN
N. Barker, S. Malherbe and J.M. Ansermino
Department of Anaesthesia, British Columbias Childrens Hospital, Vancouver, Canada

Introduction
Maintaining spontaneous ventilation in children, using total intravenous anaesthesia, is often
desirable, particularly for invasive airway procedures such as diagnostic airway endoscopy and
removal of inhaled foreign bodies. The maximum tolerated infusion rate of remifentanil during
spontaneous ventilation in combination with a volatile anaesthetic (sevoflurane) has been
studied in children1, where a large dose variation was found. This also seemed to vary widely
compared to adults, who tolerated significantly less2. Contrary to expectations however, younger
children appeared to be more resistant to the respiratory depressant effect of the opioid. The
aim of this study was therefore to determine what the effect of age is on spontaneous
respiration when anaesthesia is maintained using infusions of propofol and remifentanil.

Methods
After institutional ethics review board approval, 45 ASA I-II children, aged 6 months to 8 years
and scheduled for strabismus surgery, were stratified by age into 3 equal groups (see figure).
After induction with propofol and remifentanil, a laryngeal mask was inserted. A propofol
infusion was commenced at 300 mcg kg-1min-1 and titrated to achieve a state entropy (GE
Healthcare) value between 40 and 45. A remifentanil infusion was commenced after
spontaneous respiration was restored and titrated using a modified up and down method, and
using respiratory rate depression as a pharmacodynamic end point. Once the patient was
breathing at a rate of just greater than 10, and was stable at this end point for 10 minutes,
the rate of the remifentanil infusion was recorded. This method was used to estimate the
group mean for final remifentanil infusion rate tolerated (RD50). The inter-group comparisons
were performed using one-way ANOVA with subsequent pairwise comparisons using a
Bonferroni correction.

Results
The plot of age against the final tolerated remifentanil dose is shown in the figure. Mean and
(standard deviation) for the RD50 of groups 1 to 3 are 0.19 (0.08), 0.10 (0.04) and 0.08 (0.03)
mcg kg-1min-1 respectively. Pairwise comparisons between the groups for the rate of
remifentanil tolerated revealed a statistically significant increase in the RD50 in children less than
3 years of age compared to older children in groups 2 and 3 (p<0.001).

Figure: Final tolerated remifentanil infusion (mcg kg-1min-1) for each patient in relation to their
age (months).
                                           0.4
          Remifentanil / mcg kg -1min-1




                                          0.35
                                           0.3
                                          0.25                                                                                                  Group 1: 6 mths - 2 yrs
                                           0.2                                                                                                  Group 2: 3 yrs - 5 yrs
                                          0.15                                                                                                  Group 3: 6 yrs - 8 yrs

                                           0.1
                                          0.05
                                            0
                                                 0   6   12   18   24   30   36   42   48   54   60   66   72   78   84   90   96 102 108 114
                                                                                        Age / months
Conclusions
The results suggest that younger children, especially those aged less than 3 years, are more
tolerant to the respiratory rate depressant effect of remifentanil. This difference may be partly
due to the larger volume of distribution compared to weight observed in younger children.
However other pharmacokinetic and pharmacodynamic differences may exist in this population.
These findings confirm our clinical experience that maintaining spontaneous ventilation using
total intravenous anaesthesia in younger children and infants is a feasible and attractive
technique in situations where spontaneous ventilation is advantageous.

References
1. Ansermino JM, Brooks P, Rosen D et al. Spontaneous ventilation with remifentanil in children.
    Pediatr Anaesth 2005; 15: 115-21.

2. Peacock JE, Luntley JB, OConnor B et.al. Remifentanil in combination with propofol for
   spontaneous ventilation anaesthesia. Br J Anaesth 1998; 80: 509-11.
                   PAEDIATRIC TOTAL INTRAVENOUS ANAESTHETIC USE:
                                A NATIONWIDE STUDY
M Hill, W Peat, S Courtman.
Derriford Hospital, Plymouth Devon, UK

Introduction.
Propofol is widely used for induction and maintenance of anaesthesia in paediatric patients.
Following the initial reports of deaths following prolonged high dose infusions on intensive care
(1), the propofol infusion syndrome was described (2). The exact cause of this is still uncertain
but consistent biochemical abnormalities have been described (3,4). Initially the cases were all
in children on intensive care units, but more recently cases have been reported in adults. Of
greater concern to paediatric anaesthetists are the reports of deaths following propofol infusions
in theatre (5,6).
We set out to define the current use of propofol infusions by Paediatric Anaesthetists within the
UK.

Methods.
A list of names and addresses of paediatric anaesthetists was composed by contacting
anaesthetic departments at the hospitals by telephone and asking for the names of their
paediatric anaesthetists. An 18 question survey with an enclosed stamped, addressed envelope
was posted to 388 consultant paediatric anaesthetists in 51 hospitals throughout the United
Kingdom. The survey was re-submitted once to consultants who had not initially replied. The
results were tabulated onto a database and analysed.

Results.
We received a total of 242 replies (63% of surveyed population), 240 of which regularly
anaesthetised children. Within the last year 13% had used propofol infusions on children under
1, 31% in children 1-5 years, 41% in children 5-10 years and 46% in the over 10s. The two
most common surgical specialties with which propofol TIVA was used were ENT (n=66), and
orthopaedics (n=53), the most common operations stated being middle ear surgery, muscle
biopsy and scoliosis surgery. The reasons for using propofol in these patients were broad and
included both anaesthetic and surgical considerations. 60 consultants questioned used propofol
infusions in children at least monthly, 98 rarely and 72 never. Over 50% of replies believed
that propofol infusions reduced the rate of postoperative nausea and vomiting in respect to
inhalational techniques, less agreed that there was faster recovery time or time to discharge.
Remifentanil was commonly used with propofol infusions but target controlled infusion devices
were uncommonly used. The longest time anyone considered using propofol for was 72 hours,
although the mode of all positive responses was 6 hours. The majority of people failed to give
a maximum infusion rate.

Conclusions.
Propofol infusions are used widely throughout the UK for their perceived anaesthetic and
surgical benefits. Given that there are well documented catastrophic, albeit rare side effects, it
is surprising that there are no guidelines for infusions in theatre. Further work is required to
elucidate the exact mechanism of propofol infusion syndrome to guide future anaesthetic
practice.
References.
1. Parke TJ, Stevens JE, Rice AS et al. Metabolic acidosis and fatal myocardial failure after
propofol infusion in children: five casereports. Br Med J 1992; 305: 613616.

2. Bray RJ: Propofol infusion syndrome in children Paediatr Anaes 1998; 8: 491-499.

3. Wolf AR, Weir P, Segar P, Stone J, Shield J. Impaired fatty acid oxidation in propofol infusion
syndrome. Lancet 2001; 357: 606-607.

4. Wolf AR, Potter F. Propofol infusion in children: when does an anaesthetic tool become an
intensive care liability? Paediatr Anaesth 2004; 14: 435-438.

5. Mehta N, DeMunter C, Habibi P, Nadel S, Britto J. Short-term propofol infusions in children.
Lancet 1999; 354: 866-867.

6. Kill C, Leonhardt A, Wulf H. Lacticacidosis after short-term infusion of propofol for
anaesthesia in a child with osteogenesis imperfecta. Pediatr Anesth 2003; 13; 823-826.
  THE EFFECT OF VIDEOTAPED PREOPERATIVE INFORMATION ON PARENTAL ANXIETY
     DURING ANAESTHETIC INDUCTION FOR ELECTIVE PAEDIATRIC PROCEDURES
A.M. McEwen, C. Moorthy, C. Quantock, H. Rose
R.J. the Royal Alexandra Hospital for Sick Children, UK

Introduction
It has long been recognised that parents of children scheduled for elective surgery experience
high levels of pathological anxiety (1). Providing parents with information about anaesthesia,
surgery and postoperative recovery has been identified as a tool for reducing anxiety (2,3,4).
The purpose of this study was to determine whether audiovisual information, describing the
process of undergoing and recovering from anaesthesia, could reduce anxiety levels and desire
for information in parents before their childs induction of anaesthesia.

Methods
The study was approved by our local ethics committee. 111 Parents were recruited into this
study. Of these 56 were randomised to a control group and 55 to an intervention group. All
parents completed the Amsterdam Preoperative Anxiety and Information Scale (APAIS)
questionnaire on admission to hospital on the day of surgery and then again just before
accompanying their child to the anaesthetic room. This is a tool for assessing preoperative
anxiety and need for information, which has previously been validated in the parents of
children presenting for surgery (5). In addition to the normal preoperative preparation, parents
randomised into the intervention group watched a short 8-minute information video after
completing the first questionnaire. The video illustrated the events and procedures surrounding
a childs admission to hospital for day-case surgery, including the induction of anaesthesia.

Results
There was no statistically significant difference in child demographics, type of surgical
procedure, parental demographics, parental experience or STAI-Trait scores between the two
groups (p>0.1). A repeated measures ANOVA for APAIS scores revealed a significant group x
time interaction for all three measures, Anxiety Scale (F (1,109) = 6.2; p< 0.05), Need for
Information Scale (F (1,109)= 7.7; p<0.01) and total score (F (1,109)= 11.1; p<0.001). Further
analysis revealed that the intervention group demonstrated a reduction in anxiety (effect size
0.47), need for information (effect size 0.53) and total scores (effect size 0.63) as measured by
the APAIS, compared with controls (Figure 1).

Discussion
We postulated that audiovisual information has a role in parental education and reducing
parental anxiety before paediatric surgery. However few studies have been carried out
examining the efficacy of audiovisual information and all published studies have been carried
out in institutions in the United States. Our study is the first to examine the usefulness of
videotaped information in a childrens hospital in the UK. In this study we demonstrated that a
pre-anaesthetic educational videotape can reduce parental anxiety before paediatric day case
surgery. Our study also suggests that an information video may reduce a parents desire for
information. However as the APAIS score does not formally measure the effectiveness of
information transfer we cannot discount the possibility that the reduced desire for information
is a result of an expectation bias or may have been produced by an overly intimidating video.
We have also demonstrated that the cost of making an effective information video need not
be prohibitive. Our video was produced with the aid of our medical photography department
and the final cost was £800 ($1,487), (€1,170).
Figure 1: APAIS scores: means and standard error bars for anxiety, desire for information and
total, pre and post video.

                                            APAIS scores: means and standard error bars for anxiety,
                                              need for information, and total, pre and post video


                                       16


                                       14
                                                                                                   Total

                                       12


                                       10
                         APAIS score




                                       8
                                                                                                    Anxiety

                                       6
                                                                                                     Desire for
                                                                                                    information
                                       4

                                                                             Intervention
                                       2                                     Control



                                       0
                                                       Pre video                            Post video




Conclusions
Providing parents with an information video depicting the process of undergoing and
recovering from anaesthesia and surgery results in a significant reduction in their anxiety and
may reduce their desire for information. Future studies should examine the effect of audiovisual
information on anxiety in children before surgery.

References
1. Thompson N, Irwin MG, Gunawardene MS et al. Preoperative parental anxiety. Anaesthesia
1996; 51: 1008-1012.
2. McEwen AW, Caldicott LD, Barker I. Parents in the anaesthetic room parents and
anaesthetists view. Anaesthesia 1995; 50(4): 368
3. Shirley PJ, Thompson N, Kenward M et al. Parental anxiety before elective surgery in
children. A British perspective. Anaesthesia 1998; 53(10): 956-9
4. Lee A, Chui PT, Gin T. Educating patients about anaesthesia: A systematic review of
randomized controlled trials of media based information. Anesthesia and Analgesia 2003; 96(5):
1424-1431
5. 18. Miller KM, Wysocki T, Cassady JF, et al. Validation of measures of parents' preoperative
anxiety and anesthesia knowledge. Anesthesia and Analgesia 1999; 88: 251-7.
   A COMPARISON OF THE LARYNGEAL MASK AIRWAY WITH FACEMASK AND
OROPHARYNGEAL AIRWAY FOR MANUAL VENTILATION BY CRITICAL CARE NURSES IN
                             CHILDREN

JA Rechner, VJ Loach, MT Ali, VS Barber, JD Young, DG Mason
Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Oxford, UK

Introduction
The European Resuscitation Council recommends the laryngeal mask airway (LMA) for manual
ventilation in adult resuscitation if the skills required for the placement of an endotracheal tube
are unavailable or intubation proves impossible (1). This followed concerns about the ability of
inexperienced personnel to provide manual ventilation using traditional facemask and
oropharyngeal airway (FM/OA). If inadequate FM/OA ventilation also occurs in children, the LMA
may improve airway management during resuscitation.

Methods
Local ethical approval was obtained. We trained 19 nurses, experienced in paediatric intensive
care, emergency medicine or anaesthetics in the use of the LMA on manikins. They all had
prior experience in FM/OA ventilation. Children undergoing elective surgery were studied.
Anaesthesia was induced with propofol (3-5 mg.kg-1) or sevoflurane (8% in oxygen/nitrous
oxide) followed by a continuous infusion of propofol/remifentanil to produce apnoea. Standard
monitoring was applied and an ultrasound sensor placed above the xiphisternum to measure
anterior posterior (AP) chest expansion.
The consultant paediatric anaesthetist manually ventilated the lungs using FM/OA. The AP chest
expansion achieved was defined as the gold standard. The nurse then inserted each airway
device in random order and chest expansion was compared to the gold standard. A maximum
of 3 attempts was allowed for each airway device. Prior to the study commencing adequate
ventilation was defined as successful if 60% or more of the „gold standard‰ AP chest
expansion was achieved.

Results
The 60 children studied had a median age of 4 years (range 7 months to 8 years), and
median weight of 17 kg (range 8 to 41 kg). Using an LMA the nurses achieved successful
ventilation in 78% of children compared with 71% in the FM/OA group (p=0.39, chi squared
testing). The LMA was inserted successfully on the 1st attempt in 60%, 2nd attempt in 11% and
3rd attempt in 6% of children. Median time to first successful breath was 38 seconds (range 11
to 147 seconds) for the LMA and 24 seconds (range 15 to 48 seconds) for the FM/GA.

Discussion
Critical care nurses can
be trained to provide successful ventilation in 78% of children using an LMA. Similar studies in
adults have shown a higher proportion of successful LMA insertions than this but the
proportion of children successfully ventilated using FM/OA (70%) was higher than in adult
studies. This may be because FM/OA ventilation is easier in children. Time to successful
ventilation was faster in the FM/OA group than the LMA group, similar to adult studies. In this
group of nurses the LMA may not usefully improve the proportion of children ventilated
successfully when compared with FM/OA.
Acknowledgements. This study received funding from the Resuscitation Council (UK).
      Cumulative percentage successful   100


                                          80
                                                         FM/OA                           Figure: A cumulative frequency plot of
                                                                             LMA
                                                                                         the time to first successful ventilation
                 ventilation




                                          60
                                                                                         using the laryngeal mask airway or
                                          40                                             face mask and oropharyngeal airway.

                                          20


                                           0
                                               0   25   50    75     100   125     150
                                                         Time (seconds)




Reference
Baskett P. Guidelines for the advanced management of the airway and ventilation during
resuscitation. A statement by the Airway and Ventilation Management of the Working Group of
the European Resuscitation Council. Resuscitation 1996:31: 201-30.
                           SESSION 2
                          11.00 - 12.45

                     Chair: Dr Davandra Patel


11.00 - 12.00   Invited Lectures: The Extremely Pre-tern Infant
11.00 - 11.30   Anaesthesia in the Extreme Pre-term
                Dr Stephen Greenhough
                Manchester

11.30 - 12.00   Ventilatory Strategies
                Prof Anne Greenough
                London

12.00 - 12.45   Free papers
12.00 - 12.15   Safety and efficacy of patient controlled epidural analgesia
                following paediatric spine surgery
                S Saudan, BS von Ungern-Sternberg, D Ceroni, PA Meyer,
                A Kaelin, W Habre
                Paediatric Anaesthesia Unit, Geneva Childrens Hospital, Geneva,
                Switzerland

12.15 - 12.30   Optimal spectral irradiance for laryngoscopy
                E Lewis, TE Sheraton, MA Hampson, AR Wilkes, C Gildersleve, JE
                Hall
                University Hospital of Wales, Heath Park, Cardiff

12.30 - 12.45   Spread of local anaesthetic solution in epidural space
                visualisation with ultrasound in single shot caudals
                K.Raghavan, R.Arnold
                Department of Anaesthesia, University Hospital Lewisham, London

12.45 - 13.30   Lunch, Trade, Posters presentation/discussion


13.30 - 14.30   Annual General Meeting (APA Members only)
                    ANAESTHESIA IN THE EXTREME PRE-TERM INFANT

Dr S G Greenhough, Consultant Neonatal Anaesthetist
St Marys Hospital, Manchester, UK

Advances in neonatal care have resulted in a steady increase in the number of infants
surviving the immediate post-delivery period with gestational ages of 22-26 weeks. Inevitably a
proportion of these babies present for surgery.

Infants weighing less than 800g require considerable attention to detail if they are going to be
anaesthetised safely. In addition they test the currently available delivery systems and
monitoring to the limits.

It is certainly possible to anaesthetise babies under 800g safely but does the outcome of
surgery make it a sensible option? The widely held belief on both the Neonatal Intensive Care
Unit and the Neonatal Surgical Intensive Care Unit is that these extremely pre-term infants do
badly after surgery, indeed there have been suggestions that maybe major surgery should not
be offered to these patients.

The last seven years of our practice at St Marys has been reviewed. During this time 380
babies were admitted with birth weights ranging from 338g to 799g of which 79 required
surgery. The two commonest operations were insertion of long line and laparotomy.

In this seven year period there were, surprisingly, no intraoperative deaths despite the
extremely low birth weights and the extensive comorbidity of the babies.
The results of this seven year review are interesting. The review shows little, if any, excess
mortality in the infants having surgery compared to babies of the same birth weight who did
not require surgery. It would be unreasonable to deny these babies surgery if it is required.
              THE EXTREMELY PRETERM INFANT - VENTILATORY STRATEGIES

Anne Greenough MD DCH FRCPCH FRCP
Professor of Neonatology and Clinical Respiratory Physiology

Kings College London, MRC-Asthma Centre,Division of Asthma, Allergy & Lung Biology


Advances in perinatal care have resulted in a dramatic reduction in the mortality rate of even
very prematurely born infants. Such infants, however, frequently develop bronchopulmonary
dysplasia (BPD) with chronic oxygen dependency. They have readmissions during the first two
years after birth and suffer troublesome respiratory symptoms throughout the preschool years
and lung function abnormalities, including exercise intolerance, even as adolescents. Research,
therefore, has been directed at identifying the least damaging form of respiratory support.
Three main strategies have been investigated:

(i)     avoiding intubation and mechanical ventilation by using nasal continuous positive airway
        pressure, part of the so-called mini-touch technique. Comparison with historical and non
        randomised controls has highlighted impressive reductions in the BPD rate, but this has
        not been confirmed in the meta-analysis of the randomised trials. The trials, however,
        have been few and of small sample size

(ii)    synchronising the infants breathing efforts with the ventilator (patient triggered
        ventilation). Meta-analysis of randomised trials demonstrated the only advantage of
        assist control and synchronised intermittent mechanical ventilation was to reduce the
        duration of ventilation requirement and only in infants recovering from respiratory
        distress. Subsequently, further triggered modes have been introduced including pressure
        support ventilation and proportional assist ventilation; in addition volume control used
        with or without a trigger mode has been investigated. To date there are promising
        results in physiological studies and randomised trials with short term outcomes

(iii)   high frequency ventilation using small tidal volumes. At least eleven randomised trials
        have investigated whether prophylactic high frequency oscillation (HFO, frequencies of 10
        -15 Hz) has advantages over conventional ventilation when started in the first 12 hours
        after birth. The meta-analysis demonstrated a significant, but modest reduction, in the
        BPD rate. The trials, however, were of very different design. Long term respiratory
        follow-up is required to determine if HFO might have the advantages suggested by the
        results of studies in preclinical models

Other techniques, including liquid ventilation have been explored. The optimal form of
respiratory support in the extremely preterm infant remains to be identified.
 SAFETY AND EFFICACY OF PATIENT CONTROLLED EPIDURAL ANALGESIA FOLLOWING
                         PEDIATRIC SPINE SURGERY

S Saudan, BS von Ungern-Sternberg, D Ceroni, PA Meyer, A Kaelin, W Habre
Paediatric Anaesthesia Unit, Geneva Childrens Hospital, Geneva, Switzerland

Background
Patient controlled epidural analgesia (PCEA) is uncommon in paediatric anaesthesia particularly
for extensive spinal surgery. Since PCEA has been shown to offer superior pain control
compared with continuous epidural infusions in adults, we prospectively evaluated the analgesia
efficacy and safety of PCEA in children and adolescents following extensive spinal surgery.

Methods
Following approval of the local Ethics Committee, 100 consecutive children [age median (range)
14 (6-19) years] undergoing spinal surgery were included, and 98 children benefited from PCEA.
One or two epidural catheters were set in place by the surgeon under direct vision based on
the number of vertebral segments operated. The epidural solution consisted of bupivacaine
0.0625%, fentanyl 1 g.mL-1 and clonidine 0.6 g.mL-1, delivered at a rate of 0.2ml.kg-1.h-1 and a
bolus of 0.1 mL.kg-1.h-1(max 2 per hour). On the 4th postoperative day, PCEA was stopped and
analgesia was continued with patient controlled analgesia with morphine (PCA). After surgery,
all patients were followed by the pediatric anesthesia acute pain team for the duration of the
administration of the PCEA (day 1-4) and PCA morphine (day 4-7). Pain was assessed at rest
every 6 hours and during mobilization every 24 hours by the means of the Revised Facial
scale (RFS). All patients were continuously monitored with pulse oximetry, and every 6 hours
the respiratory frequency was assessed. The Bromage scale was used to evaluate motor
blockade (0=no paralysis; 1=inability to lift the thigh; 2=inability to flex the knee; 3=inability to
move any joint in the legs). The occurrences of postoperative nausea and vomiting (PONV),
pruritus, cardiac and pulmonary complications were reported.


Results
During the PCEA regimen, the maximal scores of the revised facial scale were below 4 at rest
with a very high satisfaction rate (>90%). Pain scores were higher during mobilization on the
first postoperative day and when PCEA was switched to PCA. The overall incidence of adverse
events was low and consisted primarily in technical problems and postoperative nausea and
vomiting. Only two children experienced a complication requiring the discontinuation of the
PCEA but there were no consequent adverse sequelae: One child with known childhood
epilepsia presented with a focal epileptic episode and one child had a suspected leak of the
anaesthetic solution into the spinal space. The switch from PCEA to PCA was associated with a
significant increase in PONV values as well as a decrease in satisfaction rates from 98% to
83%.
   Day            Max. pain Max.       pain Motor block                          PCEA / PCA
                  at Rest   during          Bromage Scale                        bolus usage
                            mobilisation
                  RFS       RFS             0     1     2                  3     received      attempted

   Day   0 PCEA   3.6   (2.9)     3.7   (3.6)         64%    26%   8%      2%    -             -
   Day   1 PCEA   3.3   (2.2)     5.3   (2.5)         48%    34%   17%     1%    7 [4-13]      9 [5-19]
   Day   2 PCEA   2.6   (1.7)     4.7   (2.2)         61%    26%   10%     2%    13.5 [7-20]   19 [11-36]
   Day   3 PCEA   2.2   (1.8)     4.0   (2.3)         77%    19%   2%      1%    17 [7-24]     21 [10-37]
   Day   4 PCEA   3.0   (2.2)     3.8   (2.0)         92%    4%    4%            9 [4-23]      11 [5-34]
   Day   5 PCA    2.5   (1.9)     4.3   (2.0)         -      -     -       -     29 [13-45]    34 [17-67]
   Day   6 PCA    2.3   (1.6)     3.5   (1.9)         -      -     -       -     22 [10-35]    25 [11-44]
   Day   7 PCA    2.6   (2.6)     3.5   (1.3)         -      -     -       -     22 [5-36]     26 [15-58]



                        Day                Sedation   Pruritus   PONV    Satisfaction
                        Day     0 PCEA     31%        4%         35%     100%
                        Day     1 PCEA     26%        6%         30%     94%
                        Day     2 PCEA     15%        13%        13%     91%
                        Day     3 PCEA     7%         11%        5%      98%
                        Day     4 PCEA     8%         8%         7%      98%
                        Day     5 PCA      8%         8%         20%     83%
                        Day     6 PCA      8%         6%         17%     100%
                        Day     7 PCA      0%         7%         9%      100%


Conclusions
The present study demonstrates that PCEA provides excellent pain relief following extensive
spinal surgery and is associated with a low incidence of adverse events. Therefore, the use of
PCEA should be encouraged in children and adolescents following extensive spine surgery.
                                               OPTIMAL SPECTRAL IRRADIANCE FOR LARYNGOSCOPY

E Lewis, TE Sheraton, MA Hampson, AR Wilkes, C Gildersleve, JE Hall
University Hospital of Wales Heath Park Cardiff, UK


Introduction
Changing the colour of light produced by laryngoscopes may improve the view at laryngoscopy
and facilitate intubation. This could be crucial in children with anatomically difficult airways and
in acute airway emergencies. Infra red light has been shown to be detrimental to optimal
laryngoscopy.1Anaesthetists have expressed a preference for blue/white light output to facilitate
intubation.2 Blue light corresponds to peak haemoglobin absorption (415nm) and therefore
enhances the view of capillary vessels within the surface mucosa.3 Green light defines deeper
structures more clearly.3 Specific combinations of blue and green light spectra may provide the
best conditions for intubation Light Emitting Diodes(LEDs) have the advantage of producing light
in a more appropriate part of the spectrum. LEDs are not currently used in laryngoscopes
available in the UK. The aim of this study was to compare the spectral irradiance of the
ProAct Miller 1 Paediatric blade laryngoscope (containing an incandescent bulb) with a custom-
made laryngoscope containing an LED.


Materials and Methods
The light spectral irradiance from the laryngoscope blades was measured under standardised
conditions using the Bentham spectroradiometer. Blackout conditions were applied to eliminate
background light. The tip of each laryngoscope blade was placed in contact with the sample
port of the spectroradiometer. A mains voltage supply was set at 3 V for the Miller 1 blade
(A) and 3.6 V for the blade with the LED (B), as specified by the manufacturers.


Results

                                                                                                                       120

                           120
                                                                                                                       100
                                                                                                                                                 (B)
                                                                                          irradiance (mW m -2 nm -1)




                           100
                                                      (A)
   irradiance (mW m nm )
  -1




                                                                                                                       80
                           80
  -2




                                                                                                                       60
                           60


                           40                                                                                          40

                           20                                                                                          20

                            0
                             400   450   500    550         600   650   700   750   800                                 0
                                                  wavelength (nm)                                                        400   450   500   550         600   650   700   750   800
                                                                                                                                             wavelength (nm)




Figure 1. Spectral irradiance from the Miller 1 blade (A) and the blade with the LED (B).

The Miller 1 paediatric blade produced spectral irradiance mainly in the infrared region(>660nm)
in contrast to the LED which produced most irradiance in the blue/green region of the
spectrum(400-550nm).
Discussion and Conclusions
Paediatric laryngoscopes with LEDs may provide superior intubating conditions than that
currently available with incandescent light sources. LEDs can be further modified to emit the
optimal spectral irradiance required for laryngoscopy. This may prove invaluable when
presented with a difficult airway.

References:
 1.Crosby E, Cleland M. An assessment of the luminance and light field characteristics of used
direct laryngoscopes. Can J Anesth 1999;46:792-6.
2.Scholz A,Farnum N,Wilkes AR,Hampson MA,Hall JE. Minimum and optimum light output of
Mackintosh size 3 blades: a manikin study Anaesthesia,(article in press).
3.Watanabe A,Tsujie H,Taniguchi M,Hosokawa M,Fujita M, Sasaki S. Laryngoscopic detection of
pharyngeal carcinoma in situ with narrow band imaging. Laryngoscope 2006;116:650-4.
   SPREAD OF LOCAL ANAESTHETIC SOLUTION IN EPIDURAL SPACE VISUALISATION
                 WITH ULTRASOUND IN SINGLE SHOT CAUDALS

K.Raghavan, R.Arnold
Department of Anaesthesia, University Hospital Lewisham, London, UK


Background
Ultrasonography is becoming an important adjunct in paediatric neuraxial blockade. Ultrasound
guidance helps in visualisation of relevant neuraxial structures, predicting depth of epidural
space from skin, reduction in bony contact and faster epidural placement. The visibility of
neuraxial structures declines in patients as age increases.
To date, there are no studies looking at the extent of spread of local anaesthetic solution in
epidural space and its correlation to the volume used, under ultrasound guidance. We report
the results of our audit on spread of local anaesthetic solution in the epidural space in single
shot caudal blocks. This abstract is based on the first 17 patients, the presentation will be
based on all 50 patients.

Methods
This audit was approved by the local audit committee. We aimed to follow the extent of the
spread of local anaesthetic within the epidural space with real time ultrasonography. Patients
were selected when the planned anaesthetic included a single shot caudal block. The
anaesthetists performing the anaesthetic and the caudal block consented to our ultrasound
visualisation. All the patients were under 5 years of age. No attempt was made to standardise
the technique, the dose, or the speed of injection. After the placement of the caudal cannula
by the primary anaesthetist involved in patient care, a separate anaesthetist, experienced in
using ultrasound, visualised the neuraxial structures and subsequent spread of the local
anaesthetic solution with real time ultrasound. The spread was followed during the injection
and for 10 seconds after the completion of the injection. A 5 cm 12 7.5 MHz linear array was
used longitudinally with either midline or paramedian approach.

Results
We are reporting the preliminary results from 17 patients. Patients were aged between 1 day
and 1 year 10 months. They weighed between 3.3 kg and 14.6 kg. Either 22 gauge Jelco or
Abbocath were used to perform the procedure. 0.25% or 0.20% L-bupivacaine was used on
all occasions. The volume administered per kg ranged between 0.33ml to 1.27ml. The visibility
of neuraxial structures was good on all occasions. On calculating the Spearmans correlation
coefficient, the extent of spread of local anaesthetic in the epidural space was positively
correlated with the volume used by a correlation coefficient of 0.64, with a p value of 0.008.
The post operative pain score in recovery was 0 in 16 out of the 17 cases. The one failure
occurred when the observed spread would not have been expected to provide analgesia for
the performed operation.

Conclusion: Among children below 5 years of age, there seems to be a positive correlation
between the volume of local anaesthetic injected into the epidural space and the extent of its
spread. This needs to be further investigated by a prospective randomised control trial.

The utility of real time ultrasound to allow a reliable achievement of a desired level of sensory
block, should be investigated i.e, whether the volume used in achieving a desired level of
local anaesthetic spread, as guided by ultrasound, provides superior analgesia and fewer
adverse effects as compared to the volume calculated using the Armitage regime.

References

   1. Ultrasound guided epidural catheter insertion in children. Paediatric Anesth Analg. 2005
      Aug;101(2):333-9
   2. Epidural catheter placement in children: comparing a novel approach using ultrasound
      guidance and a standard loss of resistance technique. Br J Anaesth. 2006
      Aug;97(2):200-7
   3. Pilot study of neuraxial imaging by ultrasound in infants and children. Paediatr Anaesth.
      2005 Aug; 15(8):671-6
                          SESSION 3
                         14.30 - 16.00


                    Chair: Dr Kathy Wilkinson

14.30 - 15.15   Free papers
14.30 - 14.45   Perioperative pain management following laparoscopic
                retroperitoneal nephrectomy
                F Flynn, T Boggs T, D de Beer
                Royal Brompton Hospital and Great Ormond Street Hospital,
                London


14.45 - 15.00   Clonidine disposition in children: A population analysis
                AL Potts*, P Larsson#, S Eksborg#, G Warman*, P-A Lönnqvist#, BJ
                Anderson*
                * University of Auckland, New Zealand, # Karolinska Institute,
                Stockholm, Sweden


15.00 - 15.15   Paediatric propofol pharmacokinetics: A multicentre study
                AE Rigby-Jones, MJ Priston, AR Wolf, JR Sneyd
                Derriford Hospital, Plymouth and Bristol Royal Childrens Hospital


15.15 - 16.00   Debate: TIVA vs Inhalation anaesthesia

                Pro TIVA                       Dr David Sapsford, Cambridge
                Pro Inhalation anaesthesia     Dr Martin Jöhr, Lucerne
                Discussion


16.00 - 16.30   Tea & Trade
  PERIOPERATIVE PAIN MANAGEMENT FOLLOWING LAPAROSCOPIC RETROPERITONEAL
                              NEPHRECTOMY
F Flynn, T Boggs T, D de Beer
Royal Bromton Hospital and Great Ormond Street Hospital, London,UK

Introduction
Retroperitoneal laparoscopic nephrectomy has been shown to be safe and effective in children, with
minimal postoperative analgesic requirements and a shorter postoperative recovery time and hospital
stay compared to the transperitoneal laparoscopic approach (1). Indeed, some centres carry this
procedure out as a day case (2). The purpose of this audit was to collate information regarding the
perioperative pain management in patients undergoing this procedure in order to determine whether
parenteral opioid analgesia is necessary postoperatively.

Methods
We retrospectively reviewed the pain management records of all patients undergoing retroperitoneal
laparoscopic nephrectomy, heminephrectomy and nephroureterectomy at our institution over a 3-year
period from September 2002 to September 2005. The following data were collected: patient
demographics, operative time, intraoperative analgesia administered, method of post operative opioid
administration, cumulative dose of opioid administered, postoperative fasting times, pain scores (FLACC)
for 48h, incidence of side effects and carer satisfaction.

Results
Retroperitoneal laparoscopic nephrectomy, heminephrectomy or nephrouretectomy was performed in a
total of 78 patients. Seventy five patients had complete pain management records and were studied (50
of these patients underwent laparoscopic nephrectomy, 18 heminephrectomy and 7 nephroureterectomy).
The median age at surgery was 5.3y (range 3.5m-17y). The median operative time was 120 min (range
40-290 min). All patients received an intraoperative opioid. Fentanyl was given to 93% of patients
(median dose 2.7mcg.kg-1) and morphine was given in addition to 53% of patients (median dose
0.07mg.kg-1). The majority of patients received intraoperative paracetamol (88%) and local anaesthetic
infiltration was administered to 83% of cases. Postoperatively, all patients received parenteral morphine,
delivered by Nurse (NCA) or Patient (PCA) Controlled infusion (67% and 33% respectively). The median
dose of morphine administered was 0.16mg.kg-1 (range 0.02-1.24mg.kg-1) and the median duration of
infusion was 19h (range 13-69h). These relatively small doses of morphine were reflected in FLACC pain
scores of less than 3 for 86% of patients in the first 24 h following surgery. Although most patients
received paracetamol postoperatively, only 27% were given a NSAID. The median time taken before first
oral intake was 4 h (range 1-24h). Despite a 21% incidence of nausea and /or vomiting on day 0
(reducing to 12% on day 1), 98% of carers rated the perioperative management as good or very good.

Conclusions
Retroperitoneal laparoscopic nephrectomy is associated with minimal postoperative opioid requirements.
Morphine PCA/NCA analgesia is therefore unnecessary for the majority of children following this
procedure. As most patients are able to take oral medications within 4 hours of surgery, regular oral
analgesics including oromorph should be adequate.

References
1 Lam JP, MacKinlay GA, et al. Endoscopic nephrectomy in children: is retro the way forward? J
Laparoendosc Adv Surg Tech A 2006; 16: 59-62.
2 Kobashi KC, Chamberlin DA, Rajpoot D, Shanberg AM. Retroperitoneal laparoscopic nephrectomy in
children. J Urol 1998; 160: 1142-4.
            CLONIDINE DISPOSITION IN CHILDREN: A POPULATION ANALYSIS
AL Potts*, P Larsson#, S Eksborg#, G Warman*, P-A Lönnqvist#, BJ Anderson*
* University of Auckland, New Zealand, # Karolinska Institute, Stockholm, Sweden

Background
There are few data describing clonidine population pharmacokinetics in children (0-15 y) despite
common use. Current paediatric data, described in terms of elimination half-life or Cmax and
Tmax, poorly explain variability in drug responses among individuals representative of those in
whom the drug will be used clinically.

Methods
Published data from 4 studies investigating clonidine PK after intravenous, rectal and epidural
administration (n= 42) were combined with an open-label study undertaken to examine the
pharmacokinetics of IV clonidine 1-2 mcg/kg bolus in children after cardiac surgery (n= 30, EC
approval granted). A population pharmacokinetic analysis of clonidine time-concentration profiles
(380 observations) was undertaken using non-linear mixed effects modelling. Estimates were
standardised to a 70 kg adult using allometric size models.

Results
Children had a mean age of 4 (SD 3.6 y, range 1 week-14 y) y and weight 17.8 (SD 12.6,
range 2.8-60) kg. A two compartment disposition model with first order elimination was
superior to a one compartment model. Population parameter estimates (between subject
variability) were clearance (CL) 14 (CV 28.3%) L/h/70kg, central volume of distribution (V1) 56.7
(67.5%) L/70kg, inter-compartment clearance (Q) 143 (19.1%) L/h/70kg and peripheral volume of
distribution (V2) 123 (72.8%) L/70kg. Clearance at birth was 4.7 L/h/70kg and matured with a
half-time of 25.5 weeks to reach 85% adult rate by one year of age. The volumes of
distribution, but not clearance, were increased after cardiac surgery (V1 180%, V2 117%). There
was a lag time of 2.6 (CV 64%) min before absorption began in the rectum. The absorption
half-life from the epidural space was slower than that from the rectum (1.04 CV 31% h vs 0.28
CV 24% h). The relative bioavailability of epidural and rectal clonidine was unity (F=1).

Conclusions
Clearance in neonates is approximately one third that described in adults, consistent with
immature clearance pathways. Maintenance dosing, which is a function of clearance, should be
reduced in neonates and infants when using a target concentration approach.
                          PAEDIATRIC PROPOFOL PHARMACOKINETICS:
                                    A MULTICENTRE STUDY
AE Rigby-Jones, MJ Priston, AR Wolf, JR Sneyd
Derriford Hospital, Plymouth and Bristol Royal Childrens Hopsital, UK

Introduction
Schuttler and Imhsens propofol pharmacokinetic (PK) model1 based on pooled adult and paediatric data
lacked information for the smallest patients. We conducted a pooled population analysis of available
neonatal and paediatric propofol PK data. The variable clinical circumstances of the individual studies
allowed us to explore health status as a PK model covariate.

Methods
We combined raw propofol blood /plasma concentration versus time data, dosing information and
demographic data from 8 paediatric studies conducted by 6 research groups, with our data 2,3. The
pooled data set comprised 197 individuals (2315 observations), aged 0.02 to 12.25 years (2.75 to 60.5kg,
median 15kg). In this preliminary population PK analysis using NONMEM, the basic model structure was
established before all model parameters were allometrically scaled to body weight. The influence of
health status on paediatric propofol PK was explored.

Results
In this 3-compartment preliminary model, post-cardiac surgery patients have significantly reduced
metabolic clearance rates (31 to 45% less when compared to healthy children or non-cardiac PICU
patients). The volume of the deep peripheral compartment in critically ill and post-cardiac surgery
children is 319% and 205% larger, respectively, than in healthy children, see Table 1.

            Parameter                         Typical               95% Confidence Interval
                                              Value
         CL (L/min)        Healthy            0.614                 0.563-0.665
                           PICU               0.767                 0.628-0.906
                           PICU cardiac       0.421                 0.366-0.476
         Q2 (L/min)                           0.839                 0.703-0.975
         Q3 (L/min)                           0.252                 0.221-0.283
         V1 (L)                               7.76                  6.33-9.19
         V2 (L)                               14.4                  12.8-16.0
         V3 (L)            Healthy            83.9                  61.4-106
                           PICU               268                   183-353
                           PICU cardiac       172                   117-227

Table 1 PK values for a child weighing 15kg

Conclusion: Health status may significantly influence paediatric propofol PK.

References
1 Schuttler J, Ihmsen H. Population pharmacokinetics of propofol: a multicenter study. Anesthesiology
2000;92:727-38.
2 Rigby-Jones AE et al. Pharmacokinetics of propofol infusions in critically ill neonates, infants, and
children in an intensive care unit. Anesthesiology 2002;97:1393-400.
3 Murray DM et al. Electroencephalograph variables, drug concentrations and sedation scores in children
emerging from propofol infusion anaesthesia Paediatr Anaesth 2004;14:143-51.
                    DEBATE: TIVA versus INHALATIONAL ANAESTHESIA

The case for TIVA

Dr David Sapsford
Cambridge, UK
DEBATE: TIVA versus INHALATIONAL ANAESTHESIA

The case for inhalation anaesthesia
1Martin   Johr , 2Thomas M. Berger
1Department    of Paediatric Anaesthesia joehrmartin@bluewin.ch, 2Neonatal and Paediatric
Intensive Care, Childrens Hospital, Kantonsspital, 6000 Luzern, Switzerland


Inhalation anaesthesia has been the standard technique for more than one and a half
centuries and thus a large experience has accumulated (1); in contrast, the option of a
controllable intravenous technique has only existed for two decades, with propofol having been
introduced in the late eighties. Undoubtedly, this agent expands the armamentarium of the
paediatric anaesthetist, e.g. for the management of the patient at risk of malignant
hyperthermia (MH), in situations with an unsecured airway, or in places outside the operating
room with no access to an anaesthesia machine with a vaporiser. But it is very debatable,
and in the authors opinion unlikely, that total intravenous anaesthesia is the only option and
will really be the future of paediatric anaesthesia (2).

Induction of anaesthesia
As a rule, „children dont like needles‰ (3), even when venous puncture can be achieved with
minimal pain after the application of EMLA cream. Induction of anaesthesia by mask is well
suited for the paediatric patient. Achieving venous access in the awake child can be avoided,
and with a skilled technique using sevoflurane in a premedicated child a smooth transition
from the awake to the anaesthetised state can be achieved (4). Earlier data showing some
psychological advantage of intravenous induction do not represent todays paediatric anaesthesia
practice (5).
When an intravenous line is already in place, proceeding with intravenous induction is a logical
choice, and under certain circumstances even mandatory, e.g. for the child with a full stomach.
The main drawbacks of propofol induction are pain on injection, bradycardia and inadequate
dosing. The „antidotal‰ use of anticholinergic drugs, opioids and lidocaine admixture (6) is
common practice.
The intravenous injection of the hypnotic drug rapidly puts the patient asleep, but concurrently
apnoea occurs, and the anaesthetist has to ventilate the child by mask in order to avoid a
rapid fall in oxygen saturation (7). Certainly, airway problems can also occur with inhalation
induction but usually appear more gradually and especially after a period of breathing an
oxygen enriched gas.

Maintenance of anaesthesia

Administration: In most cases the airway is secured by a laryngeal mask or an endotracheal
tube during general anaesthesia and the administration of inhalation agents can be done with
minimal spillage together with the oxygen enriched air for breathing. Only in cases with an
open airway, e.g. during bronchoscopy or jet ventilation, an intravenous technique is definitively
advantageous. Vaporisers represent a very reliable and fool-proof technology, which is not
always the case with intravenous pumps (8).

Dosing of inhalation agents: The key advantage of inhalation anaesthesia is the reliable dosing:
Inhalation agents are routinely measured in the expired air, and the endtial concentrations are
followed breath by breath. They give us an estimate of the arterial concentration, which, with a
short delay, equals brain concentration. We know the pharmacokinetic behaviour in every single
patient and only have to cope with the pharmacodynamic differences between the individuals
(1). Why should anaesthetists use an intravenous technique at all, as it can not be monitored
objectively (8)? In addition, the modern less soluble inhalation agents, sevoflurane and
desflurane, do not depend on metabolic processing and are rapidly eliminated from the body
by pulmonary excretion, and a rapid recovery occurs, even in tiny babies, a very vulnerable
population (9).

Dosing of intravenous agents: Dosing intravenous drugs largely depends on the size of the
patient (10). Small individuals have a relatively much larger cardiac output, e.g. 250
ml/kg/minute in an infant compared with 70 ml/kg/minute in an adolescent; therefore, in the
full term neonate the blood volume circulates three times a minute, in the adolescent patient
only once. Drugs injected into the blood stream are very rapidly distributed, and a rapid
decline of the plasma concentrations occur and consequently much lower effect site
concentrations are achieved in the target organ, the brain,. A higher bolus dose is needed for
induction in children (11), and higher infusion rates are needed during maintenance because of
the ongoing distribution to peripheral compartments (12;13). The body is filled up with propofol
and after the termination of the infusion the plasma concentrations decline much slower
compared to the adult patient. The context-sensitive halftime increases more in children
compared to adults (12). In paediatric patients, an intravenous technique is less controllable (14).
In addition, maintenance of anaesthesia by an infusion of propofol is mainly based on
assumptions even when the drug is given by a computer-controlled device. Large aberrations
from the predicted values can occur in the individual patient (15). Inadequate drug dosing may
be one explanation why awareness is much more common in paediatric patients than in
adults (16;17); repeated airway instrumentation seems to be a risk factor (18), obviously
anaesthetists are often underestimating the necessary doses. Paravenous infusions and pump
dysfunction are other typical complications of an intravenous technique.

Side effects

Emergence delirium: Clinically, the most relevant drawback of an inhalation technique is the
increased incidence of postoperative agitation, especially in pre-school children (19); this is less
of a concern when using an intravenous technique (20). The intraoperative use of opioids (21),
clonidine (22) or ketamine (23) makes a quiet awakening more likely, but even then the
emergence period following an inhalation anaesthetic needs active management. The use of an
intravenous technique is not a guaranteed remedy, as inconsolable crying can occur in a
painless child after propofol sedation, too.

Postoperative vomiting: The use of inhalation agents is one of the risk factors for early
postoperative vomiting (PONV); vomiting is no longer dependent from the anaesthetic agent
used in the later postoperative course (24). In adults, replacing halogenated inhalation agents
by propofol reduces the incidence of PONV by about 26%; a similar effectiveness could be
shown for all other interventions studied, i.e., ondansetron, dexamethasone or droperidol (25).
They all act independently and regardless of the baseline risk. PONV clearly is a relevant issue
in paediatric anaesthesia (26), and in patients at high risk, e.g. following strabismus surgery
(27), the use of a propofol-based anaesthetic combined with other preventive measures may be
a reasonable option. In the authors opinion, in all other situations, especially in children under
two years of age (26), the advantages of an inhalation technique must be weighed against
these positive aspects of propofol.
Genetic susceptibility and toxicity: The potential of provoking a MH episode is often quoted as
an argument against the use of inhalation agents; the future will show if the interference of
propofol with the mitochondrial energy delivery (28), the so-called propofol infusion syndrome,
will not evolve to a much more serious problem. It has not only been described during long-
term sedation (29-31) but also during normal anaesthetic cases (32-34), and in contrast to a
MH episode no reliable treatment has been established. The maximum duration for safe
administration of propofol is completely unknown, especially in neonates and infants. To
automatically replace sevoflurane with propofol in every patient with an unclear metabolic or
muscular disease may therefore be a wrong reflex as propofol profoundly interacts with cellular
metabolism (35).

Environmental aspects: Atmospheric pollution by halogenated hydrocarbons is a recognised
problem, however, the contribution of inhalation anaesthetic agents is very small. The use of
minimal flow circle systems - the authors use a fresh gas flow of 200 ml/minute for all cases
- allows to minimise the amount of drug used during maintenance. The breakdown of propofol
results in the production of phenol which also is not an innocuous compound (36).
Anaesthetists have to use all their skills in order to minimise waste gas exposure during mask
induction, and when combined with the use of modern scavenging systems minimal workplace
exposure can be achieved.

Anaesthetics and the developing brain: Currently, there is a vivid discussion (37;38) on the
clinical importance of neonatal rat studies showing increased apoptosis and persistent learning
deficits after a six-hour-exposure to commonly used anaesthetic drugs (isoflurane, nitrous oxide,
midazolam) (39). Unpublished data suggest that the potential of propofol to induce
neurodegenerative changes might even be more pronounced, perhaps as a consequence of
the prolonged residence time of the drug in the bodies of the experimental animals.

Conclusions
Inhalation and intravenous techniques both have indications in paediatric anaesthesia. The
feasibility of mask induction without having to obtain venous access first and the possibility to
continuously monitor the anaesthetic agent breath by breath are very significant advantages of
an inhalation technique. This is particularly true in paediatric anaesthesia where the variable
size of the patients, from 500 g to 100 kg, makes correct dosing of intravenous agents
extremely demanding.

References

    (1) Jöhr M, Berger TM. Paediatric anaesthesia and inhalation agents. Best Pract Res Clin
        Anaesthesiol 2005; 19:501-522.
   (2) Kretz FJ. The future of paediatric anaesthesia is total intravenous anaesthesia. Current
        Opinion in Anaesthesiology 2002; 15:305-307.
   (3) Jöhr M. Kinderansthesie, 6 ed. München: Elsevier, Urban & Fischer, 2004.
   (4) Aguilera IM, Patel D, Meakin GH, Masterson J. Perioperative anxiety and postoperative
        behavioural disturbances in children undergoing intravenous or inhalation induction of
        anaesthesia. Paediatr Anaesth 2003; 13:501-507.
   (5) Kotiniemi LH, Ryhanen PT. Behavioural changes and children's memories after
        intravenous, inhalation and rectal induction of anaesthesia. Paediatr Anaesth 1996;
        6:201-207.
   (6) Picard P, Tramr MR. Prevention of pain on injection with propofol: a quantitative
        systematic review. Anesth Analg 2002; 90:963-969.
   (7) Hardman JG, Wills JS. The development of hypoxaemia during apnoea in children: a
       computational modelling investigation. Br J Anaesth 2006; 97:564-570.
   (8) Rowan KJ. Awareness under TIVA: a doctor's personal experience. Anaesth Intensive
       Care 2002; 30(4):505-506.
   (9) Sale SM, Read JA, Stoddart PA, Wolf AR. Prospective comparison of sevoflurane and
       desflurane in formerly premature infants undergoing inguinal herniotomy. Br J Anaesth
       2006; 96:774-778.
 (10) Anderson BJ, Meakin GH. Scaling for size: some implications for paediatric anaesthesia
       dosing. Paediatr Anaesth 2002; 12:205-219.
  (11) Aun CS, Short SM, Leung DH, Oh TE. Induction dose-response of propofol in
       unpremedicated children. Br J Anaesth 1992; 68:64-67.
 (12) McFarlan CS, Anderson BJ, Short TG. The use of propofol infusions in paediatric
       anaesthesia: a practical guide. Paediatr Anaesth 1999; 9:209-216.
 (13) Rigby-Jones AE, Nolan JA, Priston MJ, Wright PM, Sneyd JR, Wolf AR. Pharmacokinetics
       of propofol infusions in critically ill neonates, infants, and children in an intensive care
       unit. Anesthesiology 2002; 97:1393-1400.
 (14) Aun CS, Short TG, O'Meara ME, Leung DH, Rowbottom YM, Oh TE. Recovery after
       propofol infusion anaesthesia in children: comparison with propofol, thiopentone or
       halothane induction followed by halothane maintenance. Br J Anaesth 1994; 72:554-558.
 (15) Absalom A, Amutike D, Lal A, White M, Kenny GN. Accuracy of the 'Paedfusor' in
       children undergoing cardiac surgery or catheterization. Br J Anaesth 2003; 91:507-513.
 (16) Davidson AJ, Huang GH, Czarnecki C, Gibson MA, Stewart SA, Jamsen K et al.
       Awareness during anesthesia in children: a prospective cohort study. Anesth Analg
       2005; 100:650-652.
 (17) Jöhr M. Awareness : A problem in paediatric anaesthesia? [Article in German].
       Anaesthesist 2006; 55:1041-1050.
 (18) Iselin-Chaves I, Lopez U, Habre W, Van der Linden M. Intraoperative awareness in
       children: an observational study. Paediatr Anaesth 2004; 14 :893-893.
 (19) Jöhr M. Postanaesthesia excitation. Paediatr Anaesth 2002; 12:293-295.
(20) Uezono S, Goto T, Terui K, Ichinose F, Ishguro Y, Nakata Y et al. Emergence agitation
       after sevoflurane versus propofol in pediatric patients. Anesth Analg 2000; 91:563-566.
 (21) Cravero JP, Beach M, Thyr B, Whalen K. The effect of small dose fentanyl on the
       emergence characteristics of pediatric patients after sevoflurane anesthesia without
       surgery. Anesth Analg 2003; 97:364-7.
(22) Kulka PJ, Bressem M, Tryba M. Clonidine prevents sevoflurane-induced agitation in
       children. Anesth Analg 2001; 93:335-8.
(23) Dalens BJ, Pinard AM, Letourneau DR, Albert NT, Truchon RJ. Prevention of emergence
       agitation after sevoflurane anesthesia for pediatric cerebral magnetic resonance imaging
       by small doses of ketamine or nalbuphine administered just before discontinuing
       anesthesia. Anesth Analg 2006; 102:1056-1061.
(24) Apfel CC, Kranke P, Katz MH, Goepfert C, Pappenfuss T, Rauch S et al. Volatile
       anaesthetics may be the main cause of early but not delayed postoperative vomiting:
       a randomized controlled trial of factorial design. Br J Anaesth 2002; 88:659-668.
(25) Apfel CC, Korttila K, Abdalla M, Kerger H, Turan A, Vedder I et al. A factorial trial of
       six interventions for the prevention of postoperative nausea and vomiting. N Engl J
       Med 2004; 350:2441-2451.
(26) Sossai R, Jöhr M, Kistler W, Gerber H, Schrli AF. Postoperative vomiting in children. A
       persisting unsolved problem. Eur J Pediatr Surg 1993; 3:206-208.
(27) Eberhart LH, Geldner G, Kranke P, Morin AM, Schauffelen A, Treiber H et al. The
      development and validation of a risk score to predict the probability of postoperative
      vomiting in pediatric patients. Anesth Analg 2004; 99:1630-1637.
(28) Wolf A, Weir P, Segar P, Stone J, Shield J. Impaired fatty acid oxidation in propofol
      infusion syndrome. Lancet 2001; 357:606-607.
(29) Wysowski DK, Pollock ML. Reports of death with use of propofol (Diprivan) for
      nonprocedural (long-term) sedation and literature review. Anesthesiology 2006; 105:1047-
      1051.
(30) Committee on Safety of Medicines Medicines Control Agency. Propofol (Diprivan) infusion:
      sedation in children aged 16 years or younger contraindicated. Current Problems in
      Pharmacovigilance 2001.
 (31) Cremer OL, Moons KG, Bouman EA, Kruijswijk JE, de Smet AM, Kalkman CJ. Long-term
      propofol infusion and cardiac failure in adult head-injured patients. Lancet 2001; 357:117-
      118.
(32) Kill C, Leonhardt MC, Wulf H. Lacticacidosis after short-term infusion of propofol for
      anaesthesia in a      child with osteogenesis imperfecta. Paediatr Anaesth 2003; 13:823-
      826.
(33) Mehta N, DeMunter C, Habibi P, Nadel S, Britto J. Short-term propofol infusions in
      children. Lancet 1999; 354:866-867.
(34) Salengros JC, Velghe-Lenelle CE, Bollens R, Engelman E, Barvais L. Lactic Acidosis during
      Propofol-Remifentanil Anesthesia in an Adult. Anesthesiology 2004; 101:241-243.
(35) Schenkman KA, Yan S. Propofol impairment of mitochondrial respiration in isolated
      perfused guinea pig hearts determined by reflectance spectroscopy. Crit Care Med
      2000; 28:172-177.
(36) Marx T. Global pollution - the anaesthetist's contribution. Anaesthesia 1999; 54:301-302.
(37) Jöhr M. Are anaesthetics damaging childrens brain? [Article in German] Anaesthesist
      2006; 55:465-466.
(38) Davidson A, Soriano S. Does anaesthesia harm the developing brain--evidence or
      speculation? Paediatr Anaesth 2004; 14:199-200.
(39) Jevtovic-Todorovic V, Hartman RE, Izumi Y, Benshoff ND, Dikranian K, Zorumski CF et al.
      Early exposure to common anesthetic agents causes widespread neurodegeneration in
      the developing rat brain and persistent learning deficits. J Neurosci 2003; 23:876-882.
                           SESSION 4
                          16.00 - 16.40


16.30 - 16.40   APA Awards and prizes
                Dr. Elena Vivori
                (Hon member in 2006)

                Professor Adrian Bosenberg
                (Citation by Dr. Jane Peutrell)

                Dr. Roddy McNichol
                (Citation by Dr. Neil Morton)

                Dr. Carl Rondio
                (Citation by Dr. Marcin Rawicz)




16.30 - 17.30   6th Jackson-Rees Lecture

                Baroness Susan Greenfield CBE
                Professor of Synaptic Pharmacology
                University of Oxford

                „What is Conciousness?‰
                  ANNUAL SCIENTIFIC MEETING
                   Saturday 10th May 2007


                              SESSION 5
                             09.00 - 10.30


                     Chair: Dr Robert Bingham
                Technology in Paediatric Anaesthesia


09.00 - 10.30      Invited Lectures

09.00 - 09.30      ECMO 20 years on
                   Dr Jon Smith
                   London


09.30 - 10.00      Transoesophageal ECHO for the Anaesthetist
                   Dr Frank Casey
                   Belfast


10.00 - 10.30      Monitoring respiratory mechanics
                   Dr George Meakin
                   Manchester


10.30 - 11.00      Coffee
                                   ECMO 20 YEARS ON
Dr Jon Smith
London, UK

In 1987 ECMO was at the fringes of modern critical care. The practice of sparing the lungs by
putting the patient on medium term cardiopulmonary bypass was not widely accepted. The
deployment of the ECMO in the neonatal, paediatric and adult arenas at that time was almost
wholly due to the enthusiasm and expertise of the group lead by Dr Bartlett. The late 80's
saw the end of the NIH trail (which was negative) but the foundation of ELSO and the
publication of 2 positive neonatal trials. In the 1990's the UK neonatal trial was completed
leading directly to the foundation of the UK neonatal respiratory ECMO service and ECMO
began to be used as a treatment for low cardiac output after cardiac surgery.

There have been many advances in materials and techniques; better cannulae, pumps and
oxygenators have all been successfully introduced and their performance monitored by ELSO.
Training is standardised so that ECMO has become a stereotypical technique delivered in a
similar fashion throughout the world. Developments in pumps and battery technology have
enabled more portable systems that allow the transport of infants and children whilst
undergoing this treatment.

ECMO has been used to improve the survival of children after cardiac surgery and the success
of this technique lead to the use of ECMO to "bridge" children with heart failure to heart
transplant. This experience has informed the gradual but definite move towards VAD technology
in the two UK Transplant centres. The use of ECMO in respiratory failure has also thrown up
interesting and evolving data on the variety of disorders that cause pulmonary hypertension in
newborns.

References
   1. Bartlett RH et al. Extra corporeal membrane oxygenation for newborn respiratory failure;
      45 cases. Surgery, 1982; 92:425-433
   2. Zapol WM, et al. Extra corporeal membrane oxygenation in severe acute respiratory
      failure. JAMA 1979; 242; 2193-2196.
   3. Bartlett et al. Extracorporeal circulation in Neonatal respiratory failure: A prospective
      randomised study. 1985 Pediatrics 76; 479-487
   4. ORourke et al. extracorporeal membrane oxygenation and conventional medical therapy
      in newborns with persistent pulmonary hypertension of the newborn; a prospective
      randomised study.1989 Pediatrics 84; 957-963
   5. UK Collaborative ECMO Trial Group.UK collaborative randomised trial of neonatal
      extracorporeal membrane oxygenation. Lancet, 1996, vol. 348, p. 75-82
   6. Goldman AP, et al.The waiting game: bridging to paediatric heart transplantation. Lancet
      2003: 362 : 1967-70.
   7. Jones C et al. Berlin Heart™ VAD as a bridge to transplant in children. (abstract)
      Paediatric Intensive Care Society Nov. 2006
   8. Cassidy J. The incidence and characteristics of neonatal irreversible lung dysplasia. The
      Journal of Pediatrics 2002 VOL: 141 (3), 426-8,
                   TRANS-OESOPHAGEAL ECHO FOR THE ANAESTHETIST

Dr. Frank Casey
Consultant Paediatric Cardiologist
Royal Belfast Hospital for Sick Children

The development of very small endoscopic probes means that it is now feasible to perform
Transoesophageal echocardiography (TOE) in neonates, infants and small children. TOE is
particularly useful for imaging posterior structures in the heart and can give information not
obtainable from transthoracic echocardiography.

Intraoperative TOE is useful during cardiac surgery to assess adequacy of surgical repair,
ventricular function and intravascular volume status. TOE is an essential tool in interventional
cardiology procedures such as device closure of Atrial or Ventricular Septal Defects. The
technique also has application in patients undergoing any form of major surgery allowing the
anaesthetist to have a continuous assessment of myocardial function and fluid volume status.

In Intensive TOE provides a way to assess cardiac anatomy and function when the
transthoracic window may be poor, for example, due to an open sternum or high ventilatory
requirements. The information obtained is often central to guiding postoperative management.

Transoesophageal echocardiography is therefore a very useful adjunct to the intraoperative and
intensive care management of both cardiac and non cardiac patients. In future the
development of 3D tranoseosophegeal echo will further enhance the benefits if this technique.

Whilst some Anaesthetists involved in adult cardiac surgery have developed skills in performing
TOE, this has is very rare amongst Paediatric Anaesthetists. Is there a role for the Paediatric
anaesthetist in the practice of TOE?
                           MONITORING RESPIRATORY MECHANICS

Dr George Meakin
Senior Lecturer in Paediatric Anaesthesia
Royal Manchester Children's Hospital

Improvements in equipment and technology have made it possible to monitor real time values
of respiratory mechanics during anaesthesia and in the ICU. In this review, I will describe a
typical bedside spirometry unit and the common parameters of lung mechanics that can be
obtained from it. I will also show how this information can be used minimise lung injury,
prevent atelectasis and improve patient safety during mechanical ventilation.

Spriometry unit
The Datex Ohmeda Patient Spriometry ModuleTM is an example of a spirometry system
designed for use during anaesthesia and intensive care [1,2]. It is supplied as a module on the
Datex Aestiva 5 machine, which is used routinely in our hospital. The key element of this
system is the D-liteTM flow sensor and gas sampler (Fig 1) which is placed between the
patients airway and the Y-piece of the breathing system. The velocity of gas flow is obtained
by measuring the pressure difference between ports A and B on the flow sensor. A twin-bore
tube connects these ports to a pressure sensor on the anaesthetic machine. Port C permits
continuous sampling of respiratory gases for measurement of CO2, O2, N2O and anaesthetic
agent concentrations. A paediatric flow sensor (Pedi-lite) is available for patients with tidal
volumes less than 300 ml.


Fig 1




Respiratory parameters
The respiratory parameters and gas values are displayed on the anaesthetic machine monitor,
where the effects of changing the ventilator settings are immediately visible.

Peak inspiratory pressure (Ppeak)
This is of special significance in paediatric anaesthesia since the potential leak around the
tracheal tube and high compliance of standard breathing systems dictate the use of pressure
controlled ventilation. Ppeak must initially be set at a value which ensures an adequate tidal
volume (e.g. 20 cm H2O). After this it can be adjusted with reference to the upper inflection
point (UIP) of the pressure-volume (P-V) loop and the dynamic compliance (see below).


Plateau pressure (Pplat)
This is the end-inspiratory pressure - the important distending pressure of the lungs used to
calculate dynamic compliance (see below)
PEEP
Positive end-expiratory pressure is used to prevent atelectasis. PEEP is set at a value just
greater than the lower inflection point (LIP) of the P-V loop and/or with reference to the
dynamic compliance (see below).

I:E ratio
The inspiratory: expiratory ratio (I:E ratio) must allow adequate time for the lungs to deflate or
air-trapping will occur. A typical value in adults is 1:2: in infants it is usually 1:1-1:1.5.

Tidal volume, minute volume and respiratory rate
Inspiratory and expiratory tidal volumes are obtained by integrating the flow signal with time. A
difference between the inspiratory and expiratory tidal volumes may indicate a leak in the
breathing system. Inspiratory and expiratory minute volumes are obtained by multiplying the
corresponding tidal volume by the respiratory rate.

Respiratory rate
The respiratory rate must be set to a higher value in infants and children compared with
adults reflecting their increased metabolic rate per kg. Typical values are 10-12 for adults, 12-20
for children and 20-30 for infants.

Compliance
Dynamic Compliance describes the distensibility of the lung-thoracic system: i.e. how well
volume enters into the lungs when pressure is applied to the airway. It is calculated as
follows:

            Compliance   = Expired tidal volume (ml)/Plateau pressure PEEP (cm H2O)

Typical values during mechanical ventilation are 5-15 cm H2O for infants, 15-50 ml/cm H2O for
children and 50-100 ml/cm H2O for adults. Decrease in compliance may indicate suboptimal
values of PEEP or peak pressure, increased intra-abdominal pressure or decreasing
neuromuscular blockade. When compliance decreases, the slope of the pressure-volume loop
moves towards the horizontal axis and more pressure is needed to maintain lung inflation.

Resistance
Airway resistance expresses the relationship between the pressure difference across the airway
(i.e. between the mouth and the alveoli) and the rate at which gas is flowing through the
airway. An increase in airway resistance (e.g. due to a kinked tracheal tube, bronchospasm or
airway secretions) is most easily detected as a reduction in the size of the flow-volume loop.

Pressure-volume and flow-volume loops
Pressure-volume and flow-volume loops illustrate the dynamic real-time relationships between
and pressure and volume and flow and volume respectively. Their value comes from the
pattern recognition properties of the human brain. If changes occur it is often easier to
perceive this as a change in form of a loop than by following several wave patterns. Loop
recognition aids the diagnosis of several adverse events in anaesthesia some of which have
been mentioned above. In addition, analysis of the P-V waveform can be used to optimise
patient ventilation.
Optimising patient ventilation
While mechanical ventilation is an essential part of modern anaesthetic practice, clinicians need
to be aware of the potentially harmful effects of large tidal volumes [3]. At the same time,
there must also be an awareness that anaesthesia-induced ventilatory depression, cephalad
displacement of the diaphragm and inactivation of the intercostal muscles, frequently give rise
to atelectasis in dependent parts of the lung [4]. Experience in patients with ARDS suggests that
analysis of the pressure-volume loop provides the best rationale for choosing the peak
ventilation pressure and PEEP for an individual patient [5,6].

Fig. 2.




Fig. 2 shows a theoretical pressure volume loop form a patient with ARDS divided into three
zones: A, Zone of derecruitment and atelectasis, below the lower inflection point (LIP); B, Safe
zone, between the upper and lower inflection points (LIP-UIP); C, Zone of over distension and
volutrauma, above the UIP [7]. The LIP is regarded as the opening pressure of collapsed lung
units and the target of „best PEEP‰ [8]. The UIP is regarded as the pressure at which alveolar
distension occurs; it therefore defines the upper limit of pressure during mechanical ventilation
[9]. Note that lung volume is maintained at much lower pressures on the deflation limb of the
loop; this is where normal ventilation occurs. The numerical compliance value confirms the best
possible volume-pressure relationship in patients with normal and diseased lungs [1].



References
1. Appliguide: Patient SpirometryTM: Monitoring of patient ventilation during anaesthesia.
   Datex Ohmeda, Finland.
2. Patient SpirometryTM: Clinical Interpretation in Critical Care. Datex Ohmeda, Finland.
3. Ricard J, Dreyfuss D, Saumon G. Ventilator-induced lung injury. Eur Respir J 2003; 22:
   Suppl:2s-9s.
4. Magnusson L, Spahn DR. New concepts of atelectasis during general anaesthesia. Br J
   Anaesth 2003; 91: 61-72.
5. Ranieri VM, Giuliani R, Fiore T, Dambrosio M, Milic-Emili J. Volume-pressure curve of the
   respiratory system predicts effects of PEEP in ARDS: „occlusion‰ versus „constant flow‰
   technique. Am J Respir Crit Care Med 1994; 149: 19-27.
6. Amato MBP, Barbas CSV, Medeiros DM, Magaldi RB, Shettino G de P P, Lorezi-Filho, G,
   Kairalla RA, Deheinzelin D, Munoz OR, Takagaki TY, Carvalho CRR. Effect of protective-
   ventilation strategy on mortality in the acute respiratory distress syndrome. New Eng J
   Med 1998; 338: 347-354.
7. Stewart D. Advances in Paediatric Ventilatory Support. BJA Continuing Education in
   Anaesthesia, Critical Care and Pain Journal, December 2004 (in press).
8. De Chazal I, Hubmayr RD. Novel aspects of pulmonary mechanics in intensive care. Br
   J Anaes 2003; 91: 81-91.
9. Stenqvist O. Practical assessment of respiratory mechanics. Br J Anaes 2003; 91: 92-105.
                             SESSION 6
                             11.00 - 13.30

                   Chair: Prof Andrew Wolf
11.00 - 11.30   Invited Lecture

11.00 - 11.30   Anaesthesia and the child with learning difficulties
                Dr Andy Tatman
                Birmingham, UK


                Challenging Cases
11.30 - 11.45   Dr Bernard Dalens
                Case presentation 1
                Quebec, Canada

11.45 - 12.00   Dr Per-Arne Lonnqvist
                Case presentation 2
                Stockholm, Sweden

12.00 - 12.15   Prof Adrian Bosenberg
                Case presentation 3
                Cape Town, South Africa

12.15 - 12.30   Discussion



                Ask the Experts
12.30 - 13.30   What would you do?
                Four scenarios selected from the membership


13.30           Lunch & Close of Meeting
               ANAESTHESIA AND THE CHILD WITH LEARNING DIFFICULTIES
Dr Andy Tatman
Birmingham Childrens Hospital

The definition of learning difficulties includes significantly impaired intellectual (IQ < 70) and
impaired adaptive/social functioning, which is present from childhood. Current estimates are
that there are about 60,000 children with moderate to severe learning difficulties in England
          Many children with learning difficulties are used to a fairly constant regimen of daily
living and a limited number of activities, venues and faces. Any change to this regimen can be
very stressful. Children with an autistic spectrum disorder (ASD) are a common cause of
learning difficulties and find change particularly difficult. Children with an ASD are characterised
by a triad of impairments: social interaction-difficulty developing relationships; social
communication-difficulty interpreting facial expressions, tone of voice and gestures; imagination-
difficulty in evolving play, leading to rigid patterns of limited play. In addition, resistance to
change in routine, repetitive behaviour patterns and a pedantic interpretation of information are
common
          Common procedures for children with learning difficulties include diagnostic scans,
dental and ENT procedures. Less common procedures include surgery for hip dislocation,
gastro-oesophageal reflux and scoliosis. Anaesthesia for these children can be challenging. The
change in routine to come to hospital, a noisy, cramped ward, the many new faces that get
too close, the inevitable imprecision of information, particularly timings of procedures, all
generate considerable anxiety. Some of the children have associated medical problems,
including obesity, cardiac abnormalities and epilepsy. Postoperatively, pain can be very stressful
and difficult to interpret.
          The key to successful anaesthesia is the motto to be forewarned is to be forearmed.
Pre-assessment to establish a rapport, document relevant medical problems and find out about
the childs fears and anxieties, what works and what doesnt, can be valuable. For day case
anaesthesia, children with an ASD in particular, benefit from having their hospital stay kept to
a minimum. Where possible, admit these children to a quiet side room. Premedication is often
necessary to reduce anxiety and facilitate transfer to the anaesthetic room. Midazolam
0.5mg/kg and/or ketamine 7 mg/kg, the latter particularly for the more severe end of the ASD
spectrum, are effective. If postoperative pain or nausea is anticipated, these should be
adequately treated before emergence. Patients should be discharged home as early as
possible, so they can return to their familiar environment.
For major surgery, the main difference is with postoperative analgesia. The response to opioids
may be unpredictable in children with severe learning difficulties, leading to a prolonged
emergence and the risk of aspiration of secretions. An epidural regional block offers good
intraoperative stability, facilitates rapid emergence and return of airway reflexes. Alternatively, a
caudal regional block or intraoperative remifentanil, followed by a morphine nurse controlled
analgesia regimen may be as effective. The introduction of new surgical techniques, such as
laparoscopic fundoplication has helped the management of postoperative pain and early
discharge home.
          In summary, children with learning difficulties present an anaesthetic challenge. By
understanding their particular needs, the hospital admission can be made easier for all
concerned.
                                    CHALLENGING CASE 3

          TRACHEO-OESOPHAGEAL FISTULA WITH PULMONARY SEQUESTRATION

Adrian T Bosenberg, MB ChB; FFA(SA)
University of Cape Town and Red Cross Childrens War Memorial Hospital, South Africa.

Case presentation
A term 1 day-old female weighing 2.78kg born by normal vaginal delivery in the private sector,
coughed and desaturated with first feed. Pregnancy was complicated by polyhydramnios but
her scans were considered normal. TOF suspected when the paediatrician was unable to pass
nasogastric tube. CXR revealed an abnormal opacification of the right hemithorax that was
definitely not confined to R upper lobe (typically seen after aspiration) There were 11 ribs on the
right and vertebral body of T6 was fused with 2 ribs. Cardiac echo revealed a small PDA but
normal heart. Renal ultrasound was normal. Full blood count showed an Hb 16gm, WBC
13000, platelets 265. Bilirubin and electrolytes were normal Surgery was performed on day 3.

Introduction
Oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) occur when the mesenchymal
separation of the upper foregut fails between the 4-6th weeks of gestation. The sonic
hedgehog gene may be involved in this process. Interruption of the elongation and partitioning
of the foregut causes incomplete development of the oesophagus and persistent fistulae or
clefts between the oesophageal and tracheal tubes. Up to 90 variations have been described (1)
Rare tracheo-oesophageal clefts should be considered when it is difficult to maintain adequate
ventilation. Pulmonary agenesis, often associated with absent kidney on the ipsilateral side, and
pulmonary sequestration are extremely rare but are worth considering in the presence of
abnormal hemithorax on chest radiograph (CXR).
The most common anomaly consists of a blind ending upper pouch with a distal TOF (85%).
The distal fistula is classically situated 1cm above the carina but not always and may be
situated at the carina in 30% cases. Preoperative bronchoscopy will determine the site of the
fistula(e), the presence of tracheomalacia or other tracheo-bronchial anomalies that may
influence anaesthetic management.

Surgical technique
Primary repair of OA and or TOF is optimal wherever possible. This is performed through a
right thoracotomy using an extrapleural approach. Successful thoracoscopic closure has recently
been achieved in some institutions but can provide an additional anaesthetic challenge. During
surgery the azygos vein is identified and ligated. Significant haemorrhage may occur in the
event of a ligature slipping. The fistula, usual situated deep to the azygos vein, is ligated.
Significant air leak from the trachea may occur at this stage lead to desaturation. Further
causes of desaturation include lung compression, retraction of the mediastinum by the
surgeon leading to tracheal deviation or compression or loss of cardiac output. Most consider
hand ventilation using a T-piece at this stage to coordinate ventilation with the surgery, to
detect sudden airway obstruction or changing pulmonary compliance.
The proximal pouch is identified. This can be facilitated by the anaesthetist by manipulating a
suction catheter, or even another endotracheal tube, in the upper pouch. Once the
anastomosis is almost complete a smaller trans-anastomotic tube is passed through the nose
into the stomach under direct vision of the surgeon who guides the catheter into the distal
oesophagus. This acts as a stent and facilitates subsequent feeding.
Primary anastomosis may be impossible in the presence of OA without fistula or a „long gap‰
between the proximal and distal oesophagus. A feeding gastrostomy is then fashioned and
drainage of the upper pouch achieved by either cervical oesophagostomy or a suction tube
until definitive repair can be performed. Alternatively gastric or colonic interposition may be
required at a later stage.

Specific anaesthetic considerations
The anaesthetic technique is determined by the preoperative condition and the intended
postoperative management. Surgical preference may dictate routine postoperative ventilation
whilst others are more selective and ventilate those with „long gaps‰ (anastomoses under
tension); significant associated anomalies; or when indicated by the surgical or anaesthetic
intervention.

Preoperative bronchoscopy is not performed routinely in all centres where TOF repairs are
done. Preoperative bronchoscopy can provide useful information - „But you only see what you
know!‰ Ideally bronchoscopy should be performed with the neonate breathing spontaneously so
that useful information about the airway dynamics (e.g. tracheomalacia) can also be obtained.
By using an inhalation agent (halothane, sevoflurane) and topical lignocaine 2% (limit 5mg.kg)
good conditions can be achieved. Preoperative bronchoscopy can determine the site of the
fistula(e), the calibre of the trachea, the presence of tracheomalacia or other rare laryngo-
tracheo-bronchial anomalies that may influence anaesthetic management. It is said that a right-
sided aortic arch, that may influence the surgical approach, can be diagnosed. A catheter can
be introduced to occlude the fistula or even deflate the stomach when indicated. Bronchial
toilet and aspiration for culture and sensitivity can be done at the same time.

We made a few errors that are easy to explain through the „retrospectoscope‰: What was
thought to be an abnormal carina in our patient turned out to be a narrowed trachea and an
abnormal right main „bronchus‰. On opening the chest the right lung looked atelectatic and
could be inflated. A primary anastomosis was performed uneventfully but the right lung did not
re-expand at surgery prior to closing the chest. The chest was closed before the result of a
bronchial lavage could be assessed properly. The improvement in Sp02 was taken as an
indication that the oxygenation had improved and that the lung mus have re-expanded.
Because of the late hour and abnormal preop chest X-ray (CXR) she was placed on ventilatory
support overnight.
Postoperative CXR showed little change apart form the surgery. Three hours postop she
suddenly deteriorated requiring increasing ventilatory pressures to maintain saturation. She was
eventually converted to high frequency oscillatory ventilation (HFOV). She was eventually weaned
and extubated by day 5. A gastrographin swallow on day 6 to assess the integrity of her
oesophagus demonstrated an intact oesophagus but in addition there was a „bronchogram‰ of
the right lung arising from the oesophagus. The abnormal right main bronchus seen at
bronchoscopy was in fact the fistula to the distal oesophagus and no carina per se was visible
She subsequently underwent a right pulmonary sequestrectomy. She was discharged after 35
days in NICU and is now one year old

Three other cases have been reported in the literature   (1-4)   - all have died.

References:
    1. Kluth D Atlas of esophageal atresia J Ped Surg 1976:11: 901-19.
    2. Keeley JL Schairer AE. The anomalous origin of the right main bronchus from the
        eophagus. Ann Surg 1960: 152: 871-4
3. Nikaidoh H Swenson O The ectopic origin of the right main bronchus from the
   esophagus. J Thoracic Cardiovasc Surg1971 62; 151-160.
4. Toyama WM. Esophageal atresia and tracheoesophageal fistula in association with
   bronchial and pulmonary anomalies. J Ped Surg 1972; 7: 3022-307.
ABSTRACTS OF POSTERS
 AN AUDIT OF ANALGESIA IN CHILDREN UNDERGOING THORACOTOMY FOR EMPYEMA. DOES THE
                  RISK-BENEFIT BALANCE FAVOUR EPIDURAL ANALGESIA?

A. Kotzeé1*,W. Hinton1, B. J. Carrigan2, D.C. Crabbe2
1Department   of Anaesthesia and   2   Paediatric Surgery, Leeds General Infirmary, Leeds, UK

Introduction & Aim
Uncertainty remains over the risk of epidural space infection after neuraxial blockade in the presence of
systemic sepsis. For many years, we have provided epidural analgesia to children undergoing
thoracotomy for the decortication of parapneumonic empyemas. Following recent publications asserting
that epidural analgesia is absolutely contraindicated in this situation, we audited our management. The
purpose of this audit was to document the effectiveness and the incidence of complications following
epidural insertion in children with active sepsis from empyemas.

Methods
Retrospective single-centre audit over a ten-year period.

Audit Standards
We audited our outcomes against the standards suggested in three major review articles on acute pain
management, by Dolin and colleagues. In addition, we decided that there must have been no major
complications from epidural analgesia in our audit group, for us to continue offering it to children with
active thoracic sepsis.

Results
Forty-six epidurals were performed in children with empyema, and three children were treated with
systemic opioids. There were no infective complications of the epidural space or insertion sites (0/46,
95% confidence interval 0-6%). The epidurals provided excellent analgesia, with the incidence of
moderate-severe pain (8/46, 17%) and severe pain (1/46, 2%) in the first 24 hours after surgery
exceeding published standards of 20.9% and 7.8%, respectively. These results are also far superior to
the 35.8% moderate-severe and 10.4% severe pain, achievable with patient controlled analgesia. Minor
complications of epidural analgesia (unintentional catheter dislodgement and nausea & vomiting) were
uncommon, and met the published standard. Two children receiving systemic opiates for pain relief
suffered respiratory complications related to poor analgesia, one of which resulted in a prolonged
admission to the intensive care unit.

Discussion
Epidural analgesia has many advantages over systemic opioid-based pain relief. Intravenous opiate
analgesia is therefore not the technique of choice for pain relief after thoracotomy in children, but
concern over epidural space infection means that this technique is not universally employed after
decortication of empyema. However, the evidence seems to indicate that catheter-associated epidural
abscesses are most likely to form when infection spreads from the insertion site. It therefore seems
likely that systemic sepsis increases the risk only marginally, when the epidural is inserted and
managed by experienced personnel.
There were no serious complications of epidural analgesia in our series. The only major postoperative
complications have indeed been respiratory, possibly related to not providing epidural analgesia.

Conclusion
Epidural analgesia provides excellent pain relief following thoracotomy in children with empyemas, with
a low complication rate. The risk-benefit balance may favour it over conventional analgesia with
systemic opioids.
                     DAY CASE LAPAROSCOPIC NEPHRECTOMY IN CHILDREN AN AUDIT

R.Vashisht, S Hennayake
Royal Manchester Childrens hospital Pendlebury, Manchester, UK

Introduction: The most common indication for Nephrectomy in children is Multicystic Dysplastic Kidney (MCDK). The
incidence of this is 1:4,000 live births. Non-operative management may result in hypertension or malignant
transformation1 which may occur at any age. A conservative management of these patients requires a regular
follow up at least up to the age of 5 years. The morbidity and cost implications of such an intensive follow up
makes surgical treatment more appropriate in most cases. Laparoscopic Nephrectomy in these children has
considerably altered their management. The first Laparoscopic Nephrectomy in a child was performed in 1992 by
Kavoussi and Koyle2 and in our institution in 2002. Perioperative management of adult laparoscopic surgery has
been extensively investigated. However, in children, there is little in the literature regarding anaesthetic
management of laparoscopic procedures. The duration of hospital stay for Laparoscopic Nephrectomies in children
ranged between 23 hrs3 to 2 days4

The aim: Identify techniques that improve patient outcome and reduce duration of hospital stay for Laparoscopic
Nephrectomy.

Method: Hospital Audit Committees approval was obtained to review case notes between April 2003 and
December 2005. Data collected related to indications of surgery, age distribution, duration of operation, analgesia
used, duration of hospital stay and postoperative complications.

Results: 13 patients were operated as day cases during this period. Age range was between 11 and 33 months.
Pathology in all the cases was MCDK and Laparoscopic Nephrectomy was performed by the retroperitoneal
approach. They were admitted on the morning of surgery and anaesthesia was induced using either Propofol or
Sevoflurane. Anaesthesia was maintained using oxygen, air/nitrous oxide and Sevoflurane, following intubation with
Atracurium (0.5 mg/kg). Intraoperative analgesia used in 10 of the13 cases was a combination of local anaesthetic
1 ml/kg (L.bupivacaine 0.25%) infiltration5 and either Remifentanil infusion, Morphine or Fentanyl intravenously. In the
other 3 patients, a caudal block was used. Mean duration of operation was 101.9 27.1 minutes (range of 60 to
170 minutes). Postoperatively, 4 patients did not require any analgesia, the rest were managed with a single dose
of oral analgesic (paracetamol, ibuprofen, oramorph). All the patients were discharged home on Paracetamol and
Ibuprofen. Duration of hospital stay was between 5 8 hrs. All 13 patients were followed up in the out patient
clinic and postoperative recovery was uneventful. Following this audit a further 30 patients, between the ages of
one and five years, have been successfully operated on as day cases.

Discussion: The Day Surgery report by the Audit Commission in 20016 indicated Basket procedures. The Department
of Health NHS Plan7 proposes better use of hospital capacity increasing the number of operations carried out as
day cases, to more than 75% of all operations by 2008. The quality standards for paediatric day case
management have been enshrined in the multidisciplinary report Just for the day8 and updated 9. Maintaining
these standards is as essential as considering the benefits for the children, their families and the economic
advantages. With the open technique for Nephrectomy in this hospital, an audit in 2004 showed the duration of
hospital stay was an average of 2.4 days (range 1 to 6 days). Suitable selection of patients and appropriate
perioperative management has made day case Laparoscopic Nephrectomy a possibility. Achieving these goals
requires a multidisciplinary approach with clinicians working in a child friendly and safe environment.

References:
1. Stevens LC, Li AGK, Driver CP et al. Laparoscopic nephrectomy for unilateral multicystic
    dysplastic kidney in children. Surg Endosc. 2005; 19:1135-38.
2. Harrell WB, Snow BW. Current Opinion in Urology. 2005; 15:277 81.
3. Mulholland TL, Kropp BP, Wong W. Laparoscopic renal surgery in infants 10 kg or less.
    Journal of Endourology. 2005; 19:397- 400.
4. Lorenzo GMF. Laparoscopic nephrectomy in children:transperitoneal vs the
    retroperitoneal approach. Arch Esp Urol. 2003; 56:401-13.
5. Ng A, Smith G. Intraperitoneal administration of analgesia; is this practice of any utility?
    BJA. 2002; 89:535-7.
6. Day Surgery Audit Commission; December 2001.
7. Department of Health Delivering the NHS plan, expanding capacity. 2002.
8. Just for the day. Thornes R. London: NAWCH ltd. 1991.
9. Day Surgery, 2005. AAGBI.
THE EFFECT OF VARYING CONTINUOUS PROPOFOL INFUSION ON PLASMA CGMP CONCENTRATIONS
                              IN ANESTHETIZED CHILDREN

T Engelhardt, AJ McCheyne, C Karsli, I Luginbuehl, B Bissonnette
Department of Anesthesia, The Hospital for Sick Children, Toronto, Ontario, Canada.


Introduction: The glutamate-nitric oxide-cyclic GMP pathway is potentially an effective target for
general anesthesia agents. Plasma cyclic GMP (cGMP) concentrations are reduced following an
increase in predicted plasma propofol concentrations during sedation in healthy adult
volunteers. This study hypothesized that an increase in measured plasma propofol concentration
leads to a reduction in plasma cGMP in anesthetized children.
Methods: With Research Ethics Board approval and written parental consent, a total of eighteen
healthy children aged 46.8 (19.6) months, requiring general anesthesia for lower body surgical
procedures were enrolled. Following inhalational induction, tracheal intubation and initiation of
intermittent positive pressure ventilation, caudal epidural analgesia was performed. Anesthesia
was maintained using a continuous propofol infusion adapted from a previously published
regimen to achieve predicted propofol plasma concentration of 6, 3 and 1.5 g/ml after 30, 50
and 70 min, respectively. Samples for propofol and cGMP plasma concentrations were collected
and analyzed using high-performance liquid chromatography and an enzyme immunoassay
system.
Results: The plasma cGMP concentrations varied significantly (median [range]) 19.2 [11.8-23.5],
21.3 [14.6-30.8] and 24.9 [15.7-37.8] nmol/L between each predicted plasma propofol
concentrations, P<0.0001. The correlation coefficient (r) was -0.62 (Figure 1).



                                                                       Figure 1: Scatter plot
                                                                       of measured plasma
                                                                       propofol and cGMP
                                                                       concentrations.    The
                                                                       correlation coefficient
                                                                       was r = -0.62 for
                                                                       cGMP.




Conclusions: This study demonstrates that an increase in plasma propofol concentration leads
to a decrease in plasma cGMP in healthy children and may potentially serve as a biochemical
marker for depth of propofol anaesthesia in children.
                        AWARENESS DURING PAEDIATRIC ANAESTHESIA -
                                MYTH OR TRUE CONCERN?

T Engelhardt, G Petroz, AJ McCheyne, B Bissonnette
Department of Anesthesia, The Hospital for Sick Children, Toronto, Ontario, Canada.


Introduction
The incidence of awareness in the pediatric population is reported as high as 1:125. There is
growing interest in the use of additional awareness monitors in pediatric anesthesia. An online
survey was conducted about the current perception and practice of members of the British and
French pediatric anesthesia societies regarding awareness during general anesthesia.

Method
Following the approval of the executive committees of          the British and French pediatric
anesthesia societies, all members with a valid email contact   address were invited to participate
in this web-based survey. Perceived risk factors, use of        benzodiazepines and awareness
monitors were enquired. Pre- and postoperative discussions     of awareness as well as personal
experience, workload and place of work were obtained.

Results
To date, a total of 302 (51%) have responded to the email survey. More than 60% indicated
that awareness is a problem in pediatric anesthesia with the majority estimating an incidence
of 1:1000. Almost half (49%) of the respondents believe that awareness is age dependent and
almost 50% are not concerned below 1 mo of age. With more than 76% of respondents having
more than 10 years experience in pediatric anesthesia, 86 out of 100 do not discuss the risk of
awareness or actively look for awareness in their patients despite 27% reporting at least 1
episode of awareness in their practice. Benzodiazepines are routinely used by only 22%, half of
which use them in all age groups, the remainder using it in anxious and older children. Intra-
operative monitoring almost exclusively consists of clinical signs and end-tidal anesthetic
concentrations. BIS monitoring is routinely used by approximately 10% surveyed members and
alternative means are considered irrelevant.

Conclusion
This survey demonstrates that the European pediatric anesthesiologists perceive awareness as a
major problem in pediatric anesthesia. However, none seem to address the issue openly or
look for its presence routinely. The vast majority of pediatric anesthesiologists rely almost
exclusively on clinical monitoring and end-tidal anesthetic concentrations.
                        PAEDIATRIC ANAESTHESIA IN A SEMI WAR ZONE

Dr C Doherty and Dr E Shardlow
North West Deanery, Manchester , UK

Northern Uganda: Geographically Northern Uganda is a vulnerable land. One fifth of the
Ugandan population live in the Northern provinces bordered by Sudan, The Congo and Kenya.
Surrounded by so many conflicting interests, it is no wonder it has been the scene for many
years of civil violence. It has suffered extensively at the hands of Idi Amin and has been
terrorised by the Lords Resistance Army (LRA) in the more recent years. These rebel insurgents
have abducted, mutilated and raped over 35, 000 children to serve in its „child army‰. 250
out of 100,000 children die before the age of five years and 700 out of 100,000 women die
during child birth. This is a place where the average life expectancy is 38 years.

A Safe House: St Marys hospital, Lacor in the district of Gulu was established by missionaries in
1959 and developed by an Italian Physician and his Canadian surgeon wife. Despite repeated
rebel attacks, and an Ebola outbreak in 2000, the hospital now has over 843 beds (often 2-3
per bed). It serves local people, government soldiers and the rebel army. It also offers shelter
for up to 6000 children at nightfall to avoid abduction by rebel soldiers. The corridors and
grounds of the hospital were often so full; we had to step over sleeping children to get into
the theatre at night. 5 theatres were manned by non medical anaesthetists, who were very
skilled but with superficial knowledge. The 4 bed ICU was inadequately staffed and poorly
equipped. It admitted paediatric patients in the majority.

Tools of the Trade: Anaesthetic techniques were limited. Spinals with lignocaine were used
where possible. General anaesthesia was provided with ketamine, suxamethonium and ether or
halothane through an OMV or EMO.
Due to rebel attacks, transport of oxygen was perilous so an oxygen concentrator was used
wherever needed. Monitoring was scarce and included one saturation probe and 2
sphygmomanometers to share amongst the neediest in the theatres or ICU. The anaesthesia
provider would also help clean theatre; recover patients in the corridor and clean equipment
such as the drip set, ETT and oxygen tubing for the next patient.

Our Role: During our 3 months, unpaid and unsupported, we provided the senior tier for
theatres and ICU. We regularly dealt with unexpected complications and difficult situations. We
also gave weekly tutorials, organised resuscitation workshops and introduced the safe disposal
of sharps. We also formed part of a medical outreach team treating children in IDP camps.

Common Cases: The mainstay of our work included managing neonates to adolescents.
Trauma, paediatric burns, and severe infection such as tetanus, cerebral malaria, diarrhoeal
disease and HIV related infection were common. Our experiences took us far out of the
comfort zone experienced as a trainee in the UK. We gained many skills including emergency
management of airway obstruction and resuscitation of the critically ill child.

Thanks to the AAGBI, Manchester Medical Society and The Society of Medicine for financial
support.
                              MILITARY PAEDIATRIC ANAESTHESIA
                            HELMAND PROVINCE AFGHANISTAN 2006

GA Matthews, Surgeon Commander Royal Navy, Consultant Anaesthetsit
Derriford Hospital, Plymouth, UK

Approval for this presentation has been granted by the Clinical Director, Joint Forces Medical
Group, Role 2E, Camp Bastion, Helmand Province.

All identifiable images have documented consent for medical educational usage.

British Military Forces have been deployed to Helmand Province, Afghanistan for the period April
2006 - March 2007. The Role 2E medical support is provided by Joint Forces Medical Group,
Camp Bastion. The paediatric case-mix has been considerable and varied.

Through a selection of photographic and video images, I intend to convey the extent of
paediatric anaesthetic input, in a modern conflict. This presentation will address all points on
the patient care pathway; point of wounding, helicopter emergency medical retrieval, emergency
medicine, tri-service apparatus anaesthesia, surgery, critical care and disposal.
                        TOWARDS EVIDENCE BASED PAEDIATRIC ANAESTHESIA

S Waldron, C Doherty & RJ MacKinnon, Manchester Childrens University Hospitals, UK

Evidence Based Medicine (EBM) is now entrenched in our practice, yet much of high quality
care has not been subject to rigorous assessment. The Cochrane database has a limited array
of paediatric anaesthetic topics. These topics can be labour intensive and inconclusive. We
would argue that evidence based paediatric anaesthesia, could provide more than just a review
of the highest level of evidence of a few specific topics. A traditional anaesthetic journal club
has been divided into three twenty minute sessions to facilitate this:

  1. Critical appraisal of the quality & clinical impact of a pre-selected paper
The group members pre-score a paper (1-10) that is selected according to its design, e.g. a
randomised controlled trial. Standardised questionnaires for study design, bias, result analysis,
interpretation and clinical relevance are utilised1,2. The paper is then re-scored as a group and
a final appraisal made.

2. Reviewing an aspect of EMB
The development of skills to contribute and not just critically appraise the knowledge base is
vital. The skills taught range from understanding odds ratio diagrams to internet search & filter
strategies.

3. Development of Best evidence topic reports (BETs)
Critically appraised topics summarise high level evidence on specific topics3. However rather
than discarding lower quality evidence and accepting no answer, one can appraise all the best
clinical evidence available. BETs are designed to determine the best evidence for a specific
three part clinical question1. For example, In [neonates] should [premedication be used for semi-
urgent intubation] to [optimise the procedure]?4 A search & filter strategy identifies the relevant
papers. Each paper is critically appraised and ranked according to the Oxford Centre for
Evidence-based Medicine Levels1. The Bet report details the strengths & weaknesses and ranks
each paper, and generates a clinical bottom line that answers the three part question with the
best available evidence. All Bet reports are published, many in high impact journals.

Conclusion
The traditional anaesthetic journal club can be the perfect catalyst to the development of
evidence based paediatric anaesthetic skills, in addition to keeping abreast of current literature.
Many of the searching & critical appraisal techniques are invaluable for continued professional
development in a time-limited arena. Moreover BETs provide answers for clinical questions,
stimulate debate and develop research ideas.

References
1. Mackway-Jones K, Carley SD, Morton RJ, Donnan S. The best evidence topic report: a modified CAT
for summarising the available evidence in emergency medicine. Emerg. Med. Jul 1998; 15:222- 226
2. Crombie IK, The Pocket Guide to Critical Appraisal, BMJ Publishing Group 1996 3. Sauve S, Lee HN,
Meade MD et al. The critically appraised topic: A practical approach to learning critical appraisal. Ann
Roy Coll Phys Surg Canada 1995; 28: 396-398.
4. Byrne E, MacKinnon RJ. Should premedication be used for semi-urgent or elective intubation in
neonates? Arch Dis Child. 2006; 91:79-83
 A REVIEW OF THE FIRST YEAR OF AUTOLOGOUS TRANSFUSION DURING SCOLIOSIS SURGERY IN SHEFFIELD
                                CHILDRENS HOSPITAL NHS TRUST

Scicluna J, Steel D,Eissa A, Sheffield Childrens Hospital Western Bank Sheffield S10 2TH

Introduction
• The Fresenius Continuous Auto-Transfusion System (CATS) was introduced in this hospital in Nov 2004
• Main reasons:
     Increase cost & shortage of blood bank packed cells made it more feasible to consider use
     The risk of infection from blood products, especially prions
     Other risks associated homologous blood transfusions (Ex. Human errors, anaphylaxis, untoward reactions)
Aims
     1. Did this new service lead to the expected reduction in blood bank blood use?
     2. Was there any change in transfusion trigger?
     3. Is it cost effective to run this service?
     4. Can the service be extended to other operations based on the experience gained?

Method
Two patient groups sampled:
         1: Pre cell salvage                                                                             01/01/2004         to    21/11/2004
         2: Post cell salvage                                                                            22/11/2004         to    28/11/2005

Patient characteristics
Undergoing any type of scoliosis surgery
Different aetiologies
Patients under two orthopaedic surgeons
Different anaesthetists group 1, but two main anaesthetists for group 2

Results
The results are grouped as follows:
              1. Intraop                                                                                 during the operation
              2. Postop 24hrs                                                                            after the patient left theatre during first 24 hrs
              3. Total 24hrs                                                                             includes the total units during first 24 hrs
              4. Later                                                                                   after 1st 24 hrs to discharge
              5. Total transfused                                                                        total for each patient stay
                                     No. of patients who received homologous transfusion pre- vs post-saver                          Mean blood bank units received per patient pre- vs post- saver               presav         postsav


                                                                                                                                                  2.5
                                45    42
                                                                                             presav          postsav
                                40                                                                                                                                                                                         2.0
                                           35                                                                                                     2.0                                   1.9
                                35
 N u m b e r o f p a tie n ts




                                30                                                                                                                      1.5
                                                                                 24                           24                                  1.5
                                                                                                                                     mean units




                                25                22
                                20                                                                                 18
                                                                                                                                                                                                                                 1.0
                                                                                                                                                  1.0
                                15                                                    12
                                                                10
                                10                     8                                              8                                                                                       0.6
                                                                     4                          3                                                 0.5         0.4
                                                                                                                                                                                                            0.4
                                 5                                                                                                                                    0.4
                                                                                                                                                                            0.2
                                 0                                                                                                                                                                    0.1

                                     operations    intraop    postop24hrs       total24hrs       later      tottransfused                         0.0
                                                                                                                                                        intraop     postop24hrs          tot24hrs       later              totutransf
                                                                         Hb (g/dl)
                                                                                                                                                                                        Hb (g/dl)




Conclusions
    1. Less patients received homologous blood intraoperatively when saved blood was used.
    2. Within the first 24hrs post-saver the amount of patients who received homologous transfusion halved
         (24%-11%).
    3. BUT taking the whole operative episode pre-saver 57% and post-saver 51% were transfused. Why?
    4. 23% of patients post-saver transfused in the latter post-operative period compared to 7% pre-saver.
                 PREPARATION FOR GENERAL ANAESTHESIA IN PAEDIATRIC PATIENTS

SF McDouall, W Fisher Royal Berkshire NHS Trust, London Rd Reading RG1 5AN

Introduction: Being admitted to hospital for an operation under general anaesthesia is a source of
anxiety for both children and their families [1]. Studies have shown that increasing the information
available to parents may lessen anxiety [1, 2]. One source of such knowledge is information leaflets [3].
There is currently no such leaflet available in our hospital for the paediatric population attending for
surgery or their parents. It was decided to audit the degree to which both parents and their children
felt prepared for general anaesthesia and whether there was a demand for further information.

Methods: A questionnaire was given to all parents of children attending the day surgery ward for
elective surgery over a period of 2 months. Questions assessed what information families had received
preoperatively, the impact of the anaesthetic visit and how prepared overall both parents and their
children felt for the experience of general anaesthesia. In addition parents were asked what form of
further information would be most useful in the future.

Results: 57 responses were received out of 210 families attending (27%). 39 had been seen in
preoperative assessment (68%). A further 7 families had had verbal or written information from another
source. 8 families had no information preoperatively and of these, 5 (62.5%) would have liked to have
been told more. 50 parents remembered an anaesthetic assessment and of these, 100% were satisfied
with the visit. One child had no preoperative anaesthetic assessment. 27 children (47%) met the
playtherapist on the day of the operation. When asked who had been most effective in preparing
parents and their child for the experience of anaesthesia, 44% parents felt the anaesthetic visit was
most useful in preparing themselves. In contrast, 58% felt that the ward nurses had been most
instrumental in preparing their children. On scoring the level of preparation for the general anaesthetic
from 1 to 5, the range was 2 to 5 for both parents and children. The mode of the distribution was 4
for the children and 5 for their parents. When asked what form of further information would be most
useful, written information for the parents and children was most commonly ranked either 4 or 5 out of
5. This compares to an even spread from 1 to 5 for the choices of more time at preoperative
assessment or with a playtherapist.

Discussion: The overall level of preparation scored by parents indicates a good level of satisfaction with
the information they received. This is unsurprising. Garden et al concluded, after studying responses to
three information leaflets with differing levels of explanation, that patients tend to be satisfied with the
information given to them at the time [4]. Studies show that parents prefer to have more information
and giving such information does not increase anxiety levels [2]. The desirability of further information in
the form of a leaflet for both parent and child is indicated by the high scoring of such material and by
comments written on the questionnaire forms. As a result of the audit we are designing a patient
information leaflet aimed at younger children, using pictorial and psychological techniques to optimally
impart information. We plan to repeat this audit after the introduction of the leaflets.

References
1. Thompson N et al. Pre-operative parental anxiety. Anaesthesia 1996;51:1008-1012
2. Kain ZN et al. Parental desire for perioperative information and informed consent; a two-phase study.
Anesth Analg 1997;84:299-306
3. Bellow M et al. The introduction of a paediatric anaesthesia information leaflet: an audit of its impact
on parental anxiety and satisfaction. Paed Anaesth 2002;12:124-130
     4. Garden AL et al. Anaesthesia information what patients want to know. Anaesth Intens Care
                                              1996;24:594-8
                  SLEEP MEDICINE - THE REPRESENTATION OF ANAESTHESIA IN CHILDRENS LITERATURE

SC Rawlinson and JA Short, Department of Anaesthesia, Sheffield Childrens Hospital

Introduction Many studies have shown the value of preparing children for the hospital experience, especially
admission for elective surgery (1). It is routine for parents to be sent information about their childs impending
anaesthetic, and many excellent information leaflets exist, including „Your Childs General Anaesthetic‰, produced by
the RCoA and AAGBI Patient Information Project (www.youranaesthetic.info). It is less common for children
themselves to be provided with information appropriate to their age and needs. However there are many
published childrens books which describe the hospital experience. We wished to discover how anaesthesia and
anaesthetists were represented in these texts, in order to determine which books might be recommended for
preoperative reading.

Methods Childrens books including information about hospitals were identified by searching web-based bookshops
and websites such as www.healthybooks.org.uk, using „hospital‰, „surgery‰ and „operation‰ as keywords. The
books were then read by the authors and those which involved a description of surgery were analysed in terms
of the description and representation of the accompanying anaesthetic. Particular attention was paid to certain
areas did the anaesthetist visit pre-operatively, was local anaesthetic cream applied and/or an oral pre-medication
given, was a parent present in the anaesthetic room, the mode of induction, monitoring, the description of
anaesthetic unconsciousness, recovery and analgesia. We also noted the type of illustrations used (photos or
drawings), the use of animals rather than children in the story and whether the book was multicultural.

Results We identified 23 books which featured the hospital experience as their subject. Of these, 16 contained a
surgical theme, but only 12 mentioned anaesthesia. Of these, 9 were suitable for children under 7 years and 3 for
older primary school children. Only 5 books gave a comprehensive description of the per-operative journey, from
admission to discharge. These covered many aspects of the process fasting, wearing an identification band, local
anaesthetic cream, meeting the anaesthetist, induction (both IV and inhalational), dreaming, recovery and discharge.
Post-operative pain and nausea were mentioned, but with no reference to analgesia or anti-emesis. Of these five
books, 3 featured illustrations of children, one was a photo-story of a child and one featured a cartoon turtle, who
is the star of an American TV series. Only one had multicultural appeal and this was the book which was felt to
contain the most useful (albeit American-style) information written in a very accessible style for primary school age
children „Tubes in my ears‰ by Virginia Dooley.

Discussion The value of storybooks as a means of introducing new and difficult concepts to children is clear and
is well described in the nursing literature (2). It is also suggested that reading childrens literature may be of value
in the training of paediatricians (3). A previous review of childrens literature as a source for patient education
identified the difficulties encountered when descriptions of the environment or procedures were inaccurate or dated
(4). We have identified a number of readily available childrens books which give a reasonably comprehensive and
accurate description of the anaesthetic experience. These could be of value, both as preparatory reading for the
child awaiting elective surgery, but also as a reference for anaesthetic trainees prior to their initial encounters with
children. The titles are given in the appendix.

References
1. OConnor-Von S. Preparing Children for Surgery an Integrative Research Review. AORN Journal 2000; 71 (2): 334-
343
2. Robinson R, Hughes K and Manning K. Childrens Books: a resource for childrens nursing care. Paediatric
Nursing 2002; 14 (5): 26-31
3. Rudolf MCJ and Storr E. Tell me a storyWhat can paediatricians gain from reading stories? Archives of Disease
in Childhood 2003; 88 (7): 635-637
4. Manworren RCB and Woodring B. Evaluating Childrens Literature as a Source for Patient Education. Pediatric
Nursing 1998; 24 (6): 548-553

Appendix Recommended Texts for Children facing surgery
„Tubes in my ears‰ - Virginia Dooley / Miriam Katin, Mondo Publishing 1996 (5-11      years), „Franklin goes to
Hospital‰ Paulette Bourgeois / Brenda Clark, Scholastic Inc. 2000 (3-7 years), „My    First Visit to Hospital‰ Rebecca
Hunter / Chris Fairclough, Evans Brothers Ltd 2000 (5-11 years), „Katie goes to the   Hospital‰ Barbara Taylor Cork /
Siobhan Dodds, Brimax First Experiences 2004 (3-5 years), „Going to the Hospital‰      Ann Civardi / Stephen
Cartwright, Usborne First Experiences 2000 (3-7 years).
 ANAESTHESIA FOR REVASCULARISATION PROCEDURES IN 15 CHILDREN WITH MOYAMOYA DISEASE

M D Bould, Mr Thompson, D Ganesan, S Mallory. Great Ormond Street Hospital for Children
NHS Trust, Great Ormond Street, London, WC1N 3JH.

Introduction. Moyamoya disease results in progressive occlusion of the internal carotid arteries,
associated with numerous small collateral vessels. Revascularisation procedures are used to prevent
further neurological deteriorations. The circulation of these patients is particularly susceptible to changes
in the arterial tension of CO2 and hyperventilation and crying may precipitate ischaemic symptoms.
Anaesthetic technique focuses on maintaining normocarbia, normotension, normoglycaemia, and avoiding
both anaemia and increases in blood viscosity (1). We decided to review the anaesthetic practice and
perioperative complication rate for revascularisation surgery in one centre.

Methods. We undertook a retrospective case note review of children with Moyamoya disease who had
undergone revascularisation procedures in one institution over 63 months. Baseline blood pressure was
taken from a preoperative reading on the ward. The Wilcoxon signed ranks test was used to compare
paired nonparametric variables.

Results. 15 children underwent 28 procedures: 25 direct and 3 indirect revascularisations. One procedure
was booked as an emergency and all the others were elective. All patients were intubated and
ventilated. In all patients anaesthesia was maintained with fentanyl and volatile anaesthetics. Systolic
hypotension with a pressure less than 20% of baseline was more common than hypertension (pressure
> 20% baseline, P=0.009). There was no intraoperative hypoxia in our series. The minimum recorded
end-tidal CO2 was 2.9kPa. No adverse clinical events were recorded during anaesthesia. One patient
had a significant complication noted in recovery: an episode of hypoxia due to laryngospasm. Systolic
hypertension was significantly more likely to occur in recovery or on the ward than intraoperatively
(Figure 1, P = 0.005, P = 0.003). Transfusion was required perioperatively in 4 procedures (14.8%). There
was no recorded neurological deterioration at discharge for any procedure.

Discussion. With the volatile and fentanyl based anaesthetic used in our institution, intraoperative
hypotension was more likely than hypertension. Despite this, the neurological complication rate at
discharge compared well with other series (1,2). Patients were managed on a ward postoperatively with
paracetamol and codeine, with or without nonsteroidal anti-inflammatory drugs. Hypertension was more
likely to occur postoperatively and this may have been due to suboptimal analgesia.

Conclusions. We found there to be a higher incidence of suboptimal physiological parameters
postoperatively than intraoperatively, suggesting that efforts to improve postoperative care may have the
potential to improve outcome. Depsite the high-risk nature of this patient group and documented
episodes of potentially adverse physiological parameters, an excellent overall outcome was achieved. We
conclude that whilst optimisation of the parameters above may be desirable, episodes of hypotension
do not appear to be associated with adverse outcome.

References
1. Kansha M, Irita K, Takahashi S, Matsushima T. Anesthetic management of children with moyamoya
disease. Clin Neurol Neurosurg 1997;99 Suppl 2:S110-3.
2. Miyamoto S, Nagata I, Hashimoto N, Kikuchi H. Direct anastomotic bypass for cerebrovascular
moyamoya disease. Neurol Med Chir (Tokyo) 1998;38 Suppl:294-6.
OXYGEN IN NEONATAL AND INFANT ANAESTHESIA A SURVEY OF CURRENT PRACTICE

JA Short1 and JH van der Walt2.
1Department of Anaesthesia, Sheffield Childrens Hospital, UK, 2Department of Anesthesiology, King Faisal Specialist
Hospital and Research Centre, Riyadh, Saudi Arabia.

Introduction:       There is an increasing awareness of the role of oxygen free radicals in the pathogenesis of
many diseases associated with prematurity, such as bronchpulmonary dysplasia, retinopathy of prematurity,
necrotizing enterocolitis, intraventricular haemorrhage and periventricular leukomalacia (1). The recognition of the
potential toxicity of oxygen in the newborn, has led to the recommendation that room air (21%O2) be used for
neonatal resuscitation rather than 100%O2 (2). Although this is being actively debated in the neonatal literature,
there has been little written about the potential for oxidative stress during neonatal and infant anaesthesia. Two
recent editorials reviewed some aspects of this subject (3,4). Prior to the publication of these editorials we
surveyed current practice amongst UK paediatric anaesthetists with regard to their use of oxygen during neonatal
and infant anaesthesia.

Methods: A questionnaire, an explanatory letter and a stamped, addressed envelope for return of the responses
was sent by post to 460 UK based members of the Association of Paediatric Anaesthetists of Great Britain and
Ireland. The questions sought opinions on choice of carrier gas and FiO2 for routine anaesthesia for neonates and
infants, reasons for the choice, the use of nitrous oxide and TIVA. The level of concern was also gauged
regarding the potential adverse effects of oxygen on the lungs, brain, eyes and oxidative stress in anaesthetised
premature and newborn infants. The data were analysed anonymously.

Results:
• Response rate: 247 (53.7%), of whom 94% regularly anaesthetise infants and 83% regularly anaesthetise
    neonates.
• Choice of carrier gas: 52% use Air/O2 with FiO2 <0.4 and 27% use N2O/O2 in neonates compared with 29%
    and 57% respectively in infants.
• The most commonly reported reasons for the choice of carrier gas were optimal oxygenation, the avoidance
    of pulmonary atelectasis, the analgesic properties of N2O and the type of surgery.
• 75% stated they nearly always avoid 100%O2 during routine infant anaesthesia.
• 32% stated that they actively manage FiO2 in newborns by restricting the upper limit of SaO2.
• TIVA use in neonates and infants is minimal (74% never, 24% sometimes, 2% frequently).
• Effect of anaesthetic agents on the neonatal brain: 43% concerned, 42% not and 16% did not answer.
• There were moderate to high levels of concern expressed about potential oxygen toxic effects on the eyes
    and lungs of premature babies <32 weeks but minimal concern about these effects in newborn infants.
• Only 20% of anaesthetists had any recent knowledge of these issues.
• When asked what initial action anaesthetists would take if oxygen saturation drifted down during infant
    anaesthesia, only 15% said they would increase FiO2; 50% would apply a volume recruitment manoeuvre and
    25% would use manual ventilation to improve oxygenation.

Conclusion:         This survey indicates that there is no consistency in attitudes and practices and demonstrates
considerable variation in the use of oxygen during anaesthesia in premature and newborn babies and infants.
This probably reflects a lack of awareness of the potential harmful effects of oxygen in vulnerable groups of infants
due to lack of evidence in the anesthesia literature. Further consideration and research into these issues is
probably indicated.

References
1. Jankov RP, Negus A, Tanswell AK. Antioxidants as Therapy in the Newborn: Some Words of Caution. Pediatric
     Research 2001; 50(6): 681-687
2. The International Liaison Committee on Resuscitation (ILCOR) Consensus on Science with Treatment
     Recommendations for Pediatric and Neonatal Patients: Neonatal Resuscitation. Pediatrics 2006; 117(5): e978-e988
3. van der Walt JH. Oxygen elixir of life or Trojan horse? Part 1: Oxygen and neonatal resuscitation. Pediatric
     Anesthesia 2006; 16(11): 1107-1111
4. van der Walt JH. Oxygen elixir of life or Trojan Horse? Part 2: Oxygen and neonatal anesthesia. Pediatric
     Anesthesia 2006; 16(12): 1205-1212
                         INTUBATION GRANULOMA IN A SIX YEAR OLD GIRL

O Donoghue C, O Brien K, Childrens University Hospital, Temple street, Dublin

We present the case of a six year old poly-trauma victim who developed a significant intubation
granuloma after a period of less than 48 hours intubation.
The child was a pedestrian hit by a car and thrown twenty feet in the air. In accordance with ATLS
guidelines she was uneventfully intubated in the emergency department with a size 6.0 uncuffed
endotracheal tube with in-line cervical stabilization. Her injuries included a haemopneumothorax, pelvic
fracture and liver and adrenal haemorrhages. Following appropriate stabilisation and management she
was successfully extubated less than 48 hours later and discharged from the hospital shortly thereafter.
On admission to hospital 8 weeks later for removal of k-wires it was noted that her parents had
commented on new onset snoring and a change to her voice since her accident. She underwent
uneventful general anaesthesia on this admission. They had been reassured by their local GP that this
was non significant.
On her next visit for day-case orthopaedic surgery, again a change in voice quality and snoring were
noted. Laryngoscopy was performed after an inhalational induction with sevoflurane. A 1cm nodule
crossing the mid-line below the right vocal cord was noted. The patient was maintained on
sevoflurane, self-ventilating with an LMA while urgent ENT advice was sought.
Following her orthopaedic procedure microlaryngoscopy was performed and a large granuloma was
excised arising from the right arytenoid. During microlaryngoscopy it became clear that this large tissue
mass was very mobile and held in place only by a small stalk. Failure of diagnosis may have had
serious consequences.
The patient was admitted overnight for observation and subsequently discharged home on a proton-
pump inhibitor for follow-up with the ENT and orthopaedic services.

Discussion
Intubation granuloma of the larynx is an iatrogenic disease which is induced by endotracheal intubation.
Voice rest, corticosteroids, antibiotics, antacids and surgical removal are all recognised therapies.
Intubation granuloma generally follows a period of prolonged intubation and is very rare in the
paediatric population (we found only one case in the literature).
Our case is an unusual presentation, occurring in a young child after less than 2 days of intubation. It
highlights the possibility of development of an intubation granuloma outside of the expected patient at
risk group.
Endotracheal intubation in this patient may have dislodged the granuloma from its stalk with migration
down into the lung and catastrophic consequences. Furthermore the ability of this child to cope with
respiratory tract infection would have been severely compromised.      Therefore we conclude that it is
important to investigate new voice changes, new onset snoring etc in a child with a recent intubation
to out rule or diagnose this very rare condition.

References
    1. Drosnes, DL. Laryngeal granulomatous polyp after short-term intubation of a child. Ann Otol
        Rhinol Laryngol. 1990 Mar;99(3 Pt 1):183-6
    2. Laryngeal and tracheal complications of prolonged intubation.
        Rev Laryngol Otol Rhinol (Bord). 1992;113(4):289-94
    3. Realini E. Vocal and laryngo-tracheal sequelae of prolonged intubation at the university medical
        clinic of the cantonal hospital at Lausanne.
        ORL J Otorhinolaryngol Relat Spec. 1976;38 Suppl 1:94-100
THE SHIKANI OPTICAL STYLET: A USEFUL ADJUNCT TO AIRWAY MANAGEMENT IN A NEONATE WITH
                              POPLITEAL PTERYGIUM SYNDROME

AH Jansen, G Johnston
Department of Anaesthesia, Royal Aberdeen Childrens Hospital, Aberdeen AB25 2ZN

Introduction
Popliteal pterygium syndrome is a rare autosomal dominant disorder characterised by pterygium
(popliteal webbing), syngnathia (congenital fibrous bands between the maxilla and mandible),
ankyloglossia (adhesions of the tongue to the palate), cleft lip and palate, and a variety of
extracranial abnormalities. The craniofacial abnormalities of the syndrome present unique
challenges to the paediatric anaesthetist. The Shikani Optical Stylet (Clarus medical, Minneapolis,
US) is a novel endoscope incorporating a malleable stainless steel fibreoptic stylet (Fig.1), and
can be used either with an eyepiece alone, or connected to a video camera and monitor. We
report the use of the Shikani intubating stylet in the airway management of a neonate with
popliteal pterygium syndrome and syngnathia.

Case Report
A two day old, 2.8 kg, term neonate with popliteal pterygium syndrome presented for surgical
division of syngnathia causing feeding difficulties. Other craniofacial abnormalities included a cleft
lip and palate. Preoperative airway assessment revealed a bilateral cleft lip and palate and at
least six fibrous bands connecting the maxillary and mandibular alveolar ridges, restricting
mouth opening (Fig.2). General anaesthesia was induced with sevoflurane in oxygen while
maintaining spontaneous respiration. An 2.5mm internal diameter tracheal tube was then
temporarily inserted into the childs nasopharyngeal space via the left nostril and used to
maintain anaesthesia and oxygenation. A paediatric Shikani Optical Stylet connected to a Storz
video stack, preloaded with a reinforced size 3.0 oral endotracheal tube, was then negotiated
between the lips, past the intra-oral bands, through the oropharynx and into the larynx, where
the tracheal tube was successfully deployed and the intubating stylet removed. Following
confirmation of correct placement by auscultation and capnography, the temporary nasal tube
was removed from the nostril. The child was then paralysed with atracurium while maintaining
general anaesthesia with sevoflurane in oxygen and air. Following division of the intra-oral
fibrous bands, the child was extubated awake and made an uneventful recovery.

Discussion
The airway management of children with craniofacial manifestations of popliteal pterygium
syndrome is notoriously difficult. The restricted mouth opening in particular presents unique
challenges. The Shikani Optical Stylet overcomes many of the disadvantages of techniques such
as awake fibreoptic intubation, nasotracheal intubation, and laryngeal mask airway guided
fibreoptic intubation and is a valuable addition to the paediatric anaesthetists armamentarium
for dealing with complex airway problems such as encountered in popliteal pterygium
syndrome.
    AN AUDIT OF CENTRAL VENOUS CATHETER INSERTION IN A TEACHING HOSPITAL PAEDIATRIC
                                     POPULATION

Rees LM, Aguilera IM.
Department of Anaesthetics, University Hospital of Wales, Heath Park, Cardiff CF14 4XW
Introduction
Central venous catheters (CVCs) are frequently inserted by paediatric anaesthetists as part of anaesthetic
management for elective or emergency surgery or as an option for difficult venous access, though the factors
predicting outcome in this population are poorly understood. NICE guidelines stipulate that CVCs should be inserted
under ultrasound guidance whenever possible (1) though the recommendations are largely based on adult series
with conflicting results reported for paediatric patients (2). In light of these observations we sought to determine the
factors predicting outcome (success/complications) in a large series of CVCs in our local paediatric population and
compared our practice with NICE recommendations.

Methods
Paediatric Anaesthetists (n=6) were asked to complete a questionnaire on each CVC attempted/inserted in
paediatric patients undergoing elective or emergency surgery at the University Hospital of Wales between March
2004 and September 2005. The questionnaire captured information on age, weight, site of CVC insertion, use of
siterite®, history of previous CVC insertion, number of attempted cannulations and complications.

Results
A total of 106 CVCs were inserted (23 in neonates <3kg, 12 in neonates >3kg, 57 in infants up to age 3 years, 8
in children aged 3-8 years, 6 in children >8 years). The total number of attempts was 163 (mean 1.54
attempts/patient) though this did not vary significantly according to patient age. 95 catheters were successfully
placed (89%). Successful insertion was not clearly influenced by age but was more likely in internal jugular (97%
RIJ, 93% LIJ) than femoral (83% R Fem, 64% L Fem) sites (p<0.05 for all internal jugular versus all femoral).
Femoral sites were associated with a greater number of attempts (1.83 R Fem, 1.82 L Fem 1.4 RIJ, 1.43 LIJ) and
less use of the siterite® (R Fem 74%, L Fem 73%; RIJ 100%, LIJ 93%), though siterite® use at the femoral site did not
clearly influence success. A history of previous CVC insertion was also associated with reduced success (83% in
previous CVC group, 96% in CVC-nave group; p<0.05). A total of 54 complications in 40 CVCs were observed (17
problems in cannulating vein, 11 site abandoned, 8 problems in hitting vein, 8 problems passing guide wire, 4
arterial puncture, 1 arterial cannulation, 5 others). Complications were not related to patient age but were more
likely in femoral (59% with at least one complication) compared with internal jugular (28 % with at least one
complication) sites (p<0.01). There was a tendency towards fewer complications in the 96 CVCs where the siterite®
was used (35% complications siterite® group, 60% complications no siterite® group) but this did not achieve statistical
significance. Complications were unrelated to previous CVC insertion (33% no previous CVC group, 42% previous
CVC group).

Conclusions
Site of insertion (internal jugular), low number of attempts and no history of previous CVC insertion were all
predictors of success and fewer complications. Age and the use of siterite® had less consistent results on outcome.
Site of insertion and the use of the siterite® had more consistent results for the internal jugular than for the
femoral vein. NICE recommendations on ultrasound guidance are broadly being followed at our centre and our
data support its use. However, further evaluation of the role of ultrasound guidance is needed at the femoral site.

References
1. Guidelines on the use of ultrasound device for placing central venous catheters. NICE Technology Appraisal
guidance No.49, September 2002
2. Grebenik CR et al. NICE guidelines for central venous catheterization in children. Is the evidence base sufficient?
British Journal of Anaesthesia 2004; 92(6): 827-30.
            CHILDHOOD OBESITY AND PERIOPERATIVE ANAESTHESIA-RELATED PROBLEMS

Ragoonanan V, Cagney B.
Department of Anaesthesia, Leicester Royal Infirmary, Leicester.
Aims:
1. To establish the incidence of obesity in children presenting locally for elective surgery.
2. To compare the incidence of anaesthesia-related problems in obese children (BMI >95th
centile) and non-obese children (ASA 1-2).

Methods:
A prospective questionnaire-based survey of children (2 -16 years) presenting for elective surgery
over a 3 month period (2006). The anaesthetist and recovery nurse were asked to report on
the following areas: difficulties with intravenous (IV) access, significant desaturation on induction,
desaturation on emergence, occurrence of laryngospasm, and handling/positioning difficulties.
Information regarding regional blocks was also collected: problems with insertion, identification
of landmarks and adequacy of block. The body mass index (BMI) was calculated for all children
and age-specific centiles derived from the Centre for Disease Control charts (1). A BMI above
the 95th centile was classified as obese and that above 99.6th as morbidly obese. The
incidence of adverse events in obese children was compared with that in non-obese children
using SPSS version 9 and Odds Ratio (O.R.).

Results:
191 questionnaires were analysed. Thirty-two children were obese (17%), slightly below the
national average of 18.5% in 2004 (2). Of these, 15 (9%) were classified as morbidly obese.
The survey demonstrated an increased risk of perioperative problems in the obese group (any
of the above difficulties combined: OR 4.6, 95%CI 2.0-10.5, p<0.001). Problems encountered
included difficult IV access (OR 4.3 95%CI 1.4-13.6, p=0.016), desaturation on emergence (OR 5.7
95%CI 1.5-21.0, p=0.013), and laryngospasm (OR 5.5 95%CI 1.3-23.4, p=0.028). Regional blocks
were performed in 29 patients, 9 of whom were obese (31%). An inadequate block was
significantly more likely in the obese group (p=0.005). Two manual handling problems were
reported, both in morbidly obese patients.

Conclusions:
Overall, a BMI above the 95th centile was associated with a significantly increased risk of
perioperative anaesthesia-related problems. Preoperative assessment of BMI will be useful in
predicting the occurrence of such difficulties and planning the anaesthetic management of these
children (3).

References:
1. Centres for Disease Control and Prevention. National Health and Nutrition Examinations
Survey. CDC Growth Charts.
www.cdc.gov/nchs/about/major/nhanes/growthcharts/datafiles.htm
2. Health Survey for England 2004. Updating trend tables to include childhood obesity. (2006)
www.ic.nhs.uk/pubs/hsechildobesityupdate
3. Smith H.L., Meldrum D.J., Brennan L.J.,Childhood Obesity: a challenge for the anaesthetist?
Paediatr Anaesth (2002) 12:pp750-761
   AUDIT OF ANAESTHETIC PRACTICE AND ANALGESIA FOR DENTAL EXTRACTIONS IN CHILDREN

E. Helm, R.C. Aldridge and L.M.Aldridge
Anaesthetic Department, Royal Hospital for Sick Children, Edinburgh

Introduction: Following GDC recommendations, children requiring general anaesthesia for dental
extraction are being treated in hospital settings with critical care facilities. We describe an audit
of anaesthesia and analgesia carried out over a 4 month period in children (ASA 1 -2) having
dental extractions in a childrens hospital.

Results: 353 Children, 194 boys and 159 girls, mean age 6.7yrs (2-15yr), mean weight 26.1 kg
(10.7-70kg) having a mean total of 7.5 teeth extracted. Midazolam 0.5mg/kg orally, was given
to 58 (16%) children as pre med. Induction was IV propofol (82%) or sevoflurane by mask and
maintenance was isoflurane (88%) in oxygen and nitrous oxide. An ETT was used in 153
children and an LMA in 197 with only 3 children having a face mask. The type of airway did
not influence post-op upset. In all groups an association was identified between upset at
induction and post-op and also observed in a minority of those given midazolam. Xylocaine +
adrenaline 1:80,000 was administered by the dentist. Time to discharge from arriving back on
the ward post-op was not delayed by codeine given intra-op. The dose used were: codeine
either 1mg or 1.5mg/kg IM, ibuprofen 10mg/kg (up to 400mg) orally, ondansetron 0.1mg/kg and
diclofenac 1mg/kg. 6 analgesic regimens were identified:
A        ibuprofen pre-op
B        ibuprofen pre-op + codeine IM (1mg/kg in 76%) intra-op
C        ibuprofen pre-op + codeine IM (1mg/kg in 80%) + ondansetron intra-op
D        diclofenac PR intra-op
E        diclofenac PR + codeine IM (1.5mg/kg in 70%) + ondansetron intra-op
F        codeine IM (1.5mg/kg in 70%) + ondansetron intra-op
  Grou No. of         Upset in   Upset in    Pain score Further       Vomit     Time to
  p       children    Recovery   Ward        >0          Analgesia              discharge
  A       89          12 13% 19 21%          7           10 11%       1         1.3h o/n x1
                                             8%
  B       130         7          10     7% 3             8            1         1.3h
                      5%                     2%          6%
  C       26          1          1       3% 1         3% 2       7% 0           1.5h
                      3%
  D       25          5          7           4       16% 7            0         1.7h
                      20%        28%                     28%
  E       33          1          2           0           0            0         1.3h
                      3%         6%          0%          0%
  F       48          5          6      12% 3            2            1         1.3h o/n x1
                      10%                    6%          4%

Conclusion: Analgesia with NSAIDs alone was associated with a higher incidence of children
being upset, a pain score >0 and requirement for further analgesia post-op. Despite this a
large number of children who were given ibuprofen alone, had adequate pain relief without
further analgesia. Certain groups were identified as being more prone to being upset post-op.
Younger children having more than 10 teeth out and older children having more than 4
permanent teeth out would benefit from additional codeine as well as those who are upset
pre-op either on the ward or at induction. Midazolam does not usually delay discharge. There
were only 3 cases of vomiting with 2 children requiring an overnight stay and the necessity to
administer ondansetron when codeine is given may be questioned.
  PAIN FOLLOWING LUMBAR PUNCTURE AND BONE MARROW ASPIRATES IN CHILDREN WITH ALL

L. M Aldridge, L Pittendrigh and A Lee
Anaesthetic Department, Royal Hospital for Sick Children, Edinburgh

Introduction: Treatment for Acute Lymphoblastic Leukaemia involves regular LPs for intrathecal
methotrexate over a 2-3 year period and with increased risk-directed treatment more BMAs are
required to assess disease progress. Traditionally it was thought that only children over 13 years
of age had an incidence of post dural puncture headaches similar to adults (1) but more
recently it has been shown post dural puncture headaches are not age dependent (2).
Although not thought to be significant there is a paucity of studies on pain following BMA.

Method: We carried out an audit of pain following LP and BMA in all the children, aged 2
years and over, with ALL over a 10 week period who presented on the routine haematology list
under general anaesthesia. Pain scores and interview of child and parents were carried out by
one person. This showed that following LP alone 72.4% had a pain score = 0 and that after
LP + BMA only 54.5% had a pain score = 0. We changed our practice so that all children 5
years and above had their LP using a pencil point Sprotte 24G needle, ordinarily used for those
aged 12 years and above, rather than the standard 22G cutting point spinal needle. When
BMA was also undertaken, all children of 8 years and above were given 15 mg/kg of IV
paracetamol during the anaesthetic. We re- audited over another 10 week period.
Anaesthesia in all cases was the same: IV propofol usually through an indwelling line
(Portacath or Hickman) or sevoflurane by face mask for induction, with sevoflurane in oxygen
and nitrous oxide by face mask until the procedures were complete.

Results: Pain scores from the initial audit were noticeably age related, particularly age 9 years
and over. Following the change in practice pain scores were reduced and „experienced‰
patients noted an improvement in how they felt post procedure.

Conclusions: Although pain following invasive procedures may not be severe, because it is
recurrent throughout treatment it can assume great significance for the individual child and is
recognised as one of the problem areas in chronic cancer pain (3) We suggest paracetamol
which is readily available in the IV form provides a simple solution to improve the pain
experience of a critical group of children, especially where NSAIDs and rectal medication are
generally contraindicated.

References
    1. Wee LH, Lam F, Cranston AJ. The incidence of post dural puncture headache in
        children. Anaesthesia 1996; 51:1164-6
    2. Kokki H, Salonvaara M, Herrgard E, Onen P. Postdural puncture headache is not an
        age-related symptom in children: a prospective open-randomized, parallel group study
        comparing a 22-gauge Quincke with a 22- gauge Whitacre needle. Paed Anaesth 1999;
        9:429-34
    3. Ljungman G, Gordh T, Sorensen S, Kreuger A. Pain in paediatric oncology: interviews
        with children, adolescents and their parents. Acta Paediatr 1999; 88:623-30
   SHOULD THE MODIFIED JACKSON REES AYRES-T PIECE BREATHING SYSTEM BE ABANDONED IN
                                PRESCHOOL CHILDREN?

S Saudan, W Habre, A Regli, E Schaub, TO Erb, BS von Ungern-Sternberg
Paediatric Anaesthesia Unit, Geneva Childrens Hospital, Geneva, Switzerland
Background: The Jackson Rees breathing system is commonly used for bag and mask ventilation in
preschool children, although the lack of a pressure release valve may increase the risk of gastric
insufflation. Therefore, we investigated the impact of bag and mask ventilation with a Jackson Rees
system on functional residual capacity (FRC) and ventilation homogeneity and correlated these findings to
the level of training of the anesthetist. However, it has been demonstrated that the Jackson Rees system
requires a greater peak transpulmonary pressure compared with the circle system to achieve the same
peak expiratory flows suggesting an increased resistance and thus, increasing the risk for gastric
insufflation. Therefore, we assessed in a second phase of the study, the impact of the breathing system
(Jackson Rees vs Circle system).

Methods: Following approval of the local Ethics Committee, FRC and ventilation homogeneity were
measured in 74 children (1-6 years) undergoing general surgery and the level of training of the
anesthetist was recorded. FRC was measured 1) after intubation and 2) after gastric emptying. Sixty-four
children were ventilated using a Jackson Rees System. In the second phase of the study, 10 children
were ventilated by the pediatric nursing staff using a circle system to compare the two breathing
systems in this group of anesthesia personnel.

Results: FRC and ventilation homogeneity increased in all patients following gastric emptying with the
highest improvement (25%) being observed when nurse students were in charge of the ventilation with
the Jackson-Rees system. The lowest changes in FRC and ventilation homogeneity were observed when
pediatric consultants were in charge, whereas ventilation by the pediatric nurse anesthetists led to a
significant gastric insufflation. The circle system was associated with significantly less gastric insufflation
than the Jackson Rees system.




Conclusions: The efficacy of bag and mask ventilation was highly dependent on the training of the
anesthetist with consultants demonstrating significantly better skills than any of the other groups. The use
of a circle system by the pediatric nursing staff instead of a Jackson Rees system was associated with a
significantly lower gastric insufflation suggesting that Jackson Rees system should be primarily considered
in the hands of pediatric consultants whereas the circle system appears to be safer in less trained
anesthetists.
THE EFFECTS OF INTRODUCTION OF ROYAL COLLEGE OF ANAESTHETISTS GUIDANCE 1999 ON PAEDIATRIC ANAESTHETIC
                                PRACTICE AT A DISTRICT GENERAL HOSPITAL

Poolacherla R, Great Ormond Street Hospital London

Introduction: To investigate whether the implementation of RCOA guidelines on Paediatric Anaesthetic services (1)
has produced a change in the delivery of services with regards to the paediatric anaesthesia.

Methods: Study period 1996 - 2003
    • Data was collected from theatre data base (Swiftop) and analysed by Age, Specialty, First and second
        anaesthetist, time of day, ASA grade and Procedure.
    • Cases were split by age group: Under 1, 1-3 yrs, 4-5 yrs, 6-10 yrs and 11-15 yrs.
    • Out of hours was defined as between 18:00 and 08:00 and anytime on a Saturday or Sunday.
    • Elective = elective & scheduled, Emergency= urgent & emergency
    • Also looked at teaching and training opportunities.

Results: The total number paediatric patients showed a steady increase with an average of about 2300 children
under going anaesthesia every year over the study period. A sudden increase in the number of cases was noted
in the year 2000 was due to closure of community dental services around the region and also centralising local
paediatric services. An analysis of in-hours and out of hours work in the 3 age groups namely under1, 1-3 years,
and under 5.
found a sharp decline in the work done out of hours after 1999 when NCEPOD recommendations were
implemented at the hospital (figure 1). We also looked at the teaching and maintenance of skills by looking at the
involvement of a second anaesthetist either as a Consultant, NCCG or a trainee. We found only about 25-30%
lists had a second anaesthetist.

Discussion; Following the 1989 NCEPOD report (2) a huge debate emerged as to where and by whom paediatric
anaesthesia should be performed. Our analysis of the data between 1995-2003 showed that there are enough
numbers to maintain skills and perform with safety in a DGH although best use is not made of the training
opportunities. Review of NCEPOD by Lunn suggested that equivalent ongoing experience can be gained if an
anaesthetist could anaesthetise , Infant <6months-12/year, 3years-50/yearalthough there is no evidence base to
support these figures. We would have liked to present information on critical incidents reported along side our
workload figures but robust reporting systems were not in place for most of the time period. Provision of a
separate paediatric on call rota is not feasible given staffing numbers and caseload and we suggest that
anaesthetic training should produce Consultants capable of anaesthetising children over one year of age for the
minor, often superficial emergency procedures in ASA 1 & 2 children that form the majority of the emergency
workload in a DGH.

Conclusion: Though the number of children remained the same there was a reduction in numbers done out of
hours with more are being done by Paediatric anaesthetists. Only 25-30% of elective cases showed a second
anaesthetist, therefore training and teaching opportunity is underutilised.

References
1. RCOA Guidelines for the provision of Anaesthetic Services 1999
2. The Report of the National Confidential Enquiry into Perioperative Deaths.London: NCEPOD 1989.

Figure 1
                                                      Paediatric Cases Out of Hours (18:00-08:00 and weekends)

                                                     60
                                Number of cases




                                                     40



                                                     20



                                                      0
                                                            1996   1997   1998   1999          2000   2001   2002   2003
                                                  <1 yr       5     12     4      4              0      4      0      2
                                                  1-3 yrs    33     40     37     48            26     25     26     26
                                                  4-5 yrs    21     33     39     28            21     20     18     22
                                                                                        Year
 CLINICAL USEFULNESS OF THE SIMULTANEOUS DISPLAY OF PULSE OXIMETRY FROM TWO PROBES

K Wouters; J Pook; R Arnold
University Hospital Lewisham NHS Trust

Introduction:
Pulse oximetry is a vital monitoring tool during general anaesthesia, capable of identifying
changes in the patients cardiorespiratory status. However oximeters are particularly prone to
false alarms and dropout (loss of trace) in small infants, which often results in interruption to
surgery to ascertain the true nature of the saturation (SpO2).

Methods:
This is an observational audit conducted in infants less than 5 kg undergoing general
anaesthesia. Prior to surgery 2 saturation probes ( Nellcor Dura-Y) were placed on different
limbs on each infant. The digital readout of O2 saturation and its plethysmographic waveform
were displayed simultaneously on Philips Medical CMS monitoring (software Rev C). The patients
age, weight, type of surgery, position of probe 1 and 2 and the position of non-invasive blood
pressure monitoring was noted. During anaesthesia the differences in the SpO2 and the
possible causes thereof were noted.

Preliminary results (Audit still in progress):
21 infants were observed with a mean weight of 3.13kg. The type of surgery performed varied
from inguinal hernia repair to laparotomy.
The table below outlines the differences noted

     Dropout throughout for 1 probe                 2 patients
     Dropout intermittently for 1 probe             4 patients
     SpO2 <85% for 1 probe intermittently           4 patients
     whilst 2nd probe >95%
     >2% difference in SpO2 intermittently/         9 patients
     throughout with good traces in both
     probes
     <2% difference in SpO2 throughout              2 patients (9.5% OF CASES)

The potential causes for dropout/ reduced SpO2 were not obvious in 75% of cases, the
remainder were due to motion artefact and poor perfusion.

Conclusion:
The simultaneous display of two oximeter probes is extremely useful especially in small,
compromised infant undergoing prolonged procedures. In only 9.5% of cases might the oximetry
been adequate with only one probe attached. Having two oximeters alleviates anxiety
otherwise caused by falsely low SpO2 readings and periods of dropout.

References:
Jubran A. Pulse Oximetry. Critical Care 1999; 3(2):11-17
    RESOURCE IMPLICATIONS OF THE RESUSCITATION AND STABILISATION OF SICK CHILDREN IN A
                                    UNIVERSITY HOSPITAL

Morris R, Prinzhausen H, Wilkinson K, Norfolk and Norwich University Hospital NHS Trust

Introduction: There has been a marked change in Practice in the UK over the last 10 years, with regard to the
care of sick children in centralised Paediatric Intensive Care Units ( PICUs ) rather than in adult facilities in their
local hospital i . These children require initial resuscitation and stabilisation wherever they present. However, an
increasing number of anaesthetists report that they are deskilled in this area due to parallel changes in the way
that anaesthesia for children is delivered. A recent Department of Health working group made specific
recommendations to address this problem ii . We report the results of a review of the resource implications of the
early care of sick children in a large university hospital, which is relatively isolated geographically, and without an
on site PICU. This has implications for the planning and organisation of facilities in the future.

Methods: We performed a retrospective notes review over 2 years (2004-2006) with the approval of the local
audit department, Research Ethics Committee and Childrens Critical Care Working Group (CCWG). Patients were
identified using a combination of the ICU database, minutes of the CCWG and the theatre information system.
Notes were excluded if a child was electively admitted to HDU/ICU e.g. after major surgery in a small number of
older children.

Results: 27 sets of notes indicated that the child had received emergency admission to intensive care. 2 were
excluded as they were non informative. Of the 25 patient records subsequently reviewed, we observed the
following :
The mean age of the children identified was 6.1 years (range 2months-15 years)
76% (19) were transferred to a PICU, 17 of which were retrieved (2 were transferred by ourselves). 10 patients
underwent transfer from ICU, 5 from theatres, 1 from Accident and Emergency, and 1 from NICU.
In 15 patients we were able to identify the time spent in hospital prior to transfer to PICU during which they
received level 1 or 2 intensive care. The mean duration was 7.3 hours (Range 2-55 hours). Mean length of stay
for those not transferred was 19.4 hours in the adult HDU/ICU facility.
In 20 patients we were able to calculate a TISS score, the mean score was 29 (range 21-48).
A consultant anaesthetist was clearly documented as having been directly involved in the care in 18 cases. In 4
cases 2 consultant anaesthetists were involved. In the remainder documentation indicated that the minimum grade
was an SpR.

Discussion: Documentation of the care of critically ill children in our hospital has not previously been formally
examined. We have discovered that it is often difficult to ascertain information retrospectively in this situation.
However, it is clear that in our unit there is a large input of resource when a sick child presents, which includes
senior anaesthetic personnel.

Conclusions: Anaesthetists in hospitals without PICUs are often involved for many hours in the care of sick
children. This has implications for the competencies required which extend beyond the „golden hour‰. The
recommendation is that care is delivered by a team which extends across directorates 2. Trusts need to stock a
range of appropriate equipment for these relatively unusual situations, making sure that it is regularly checked and
in date. They may also need to be made aware of the cost and service implications of this work.
The quality of medical record keeping in other areas of care is known to be poor 3. We were therefore not
surprised that much of the data we hoped to find was missing in this retrospective review. We feel that this work
should form the basis of a prospective ongoing survey.

1 Paediatric Intensive Care-a framework for the future. UK co-ordinating group on Paediatric Intensive Care/ NHS
executive;1997.
1 Care of the Critically ill or injured child in the District General Hospital-a team response. DH, 2006 ; Gateway
4758: www.dh.gov.uk
3Mann R, Williams J. Standard in medical record keeping. Clin Med. 2003 Jul-Aug;3(4):329-32
       THE EFFECT OF SEVOFLURANE ON FILTRATION PERFORMANCE OF PAEDIATRIC BREATHING SYSTEM FILTERS

SR Froom, C Gildersleve, C Cann, AR Wilkes, JE Hall
University of Wales College of Medicine and Department of Anaesthesia and Intensive Care, Cardiff.

Introduction: The European standard for breathing system filters (BSF) tests filtration performance by challenging
filters with an aerosol of sodium chloride particles [1]. The standard for filters was based on the standard for
respiratory protective devices: this standard suggests that oil may degrade the performance of filter material [2]. A
decrease in performance of BSF due to exposure has also been demonstrated [3,4]. Sevoflurane is a commonly
used volatile agent, which is used in paediatric anaesthesia. Volatile anaesthetic vapours are organic and hence
may affect the filtration performance of BSF during anaesthesia. The filtration performance of two filter models was
measured following exposure to sevoflurane.

Methods: The pressure drop across 20 samples of both Hygroboy (Mallinckrodt DAR, Mirandola, Italy) and
Hygrobaby (Mallinckrodt DAR, Mirandola, Italy), both being paediatric electrostatic filters were measured at a flow
of 15 L min-1. This was performed to ensure the filters were batched appropriately, as each filter may have a
slightly different pressure drop. Five samples of each model were exposed to sevoflurane at one of the following:
3.6% for 4 hours in air at a flow of 2 L min-1, 1.8% for 1 hour in air at a flow of 2 L min-1.and at 1.8% for 1
hour in air at a flow of 2 L min-1. Five samples of each model were also not exposed. The filtration
performance of all samples, including those samples not exposed to sevoflurane, were then measured using a
Moores test rig (SFP Services, Christchurch, UK) at a flow of 12 L min-1. General linear modelling (SPSS 14, SPSS,
Inc., Chicago, IL) was used to analyse the penetration results with sevoflurane added as a factor and pressure
drop added as a covariate. Local research ethics committee approval was not required.

Results:
Filter             Group            Pressure drop (cmH2O)                     Penetration (%)
Hygrobaby          Air only         2.9 [2.5 to 4.0]                          3.3 [2.1 to 6.4]
                   1 Mac 1 h        3.0 [2.3 to 3.2]                          3.5 [2.5 to 8.0]
                   2 Mac 1 h        2.9 [2.5 to 3.5]                          4.4 [2.5 to 5.5]
                   1 Mac 4 h        2.8 [2.2 to 3.2]                          5.2 [3.1 to 9.1]
Hygroboy           Air only         1.4 [1.3 to 1.5]                          2.1 [1.7 to 2.4]
                   1 Mac 1 h        1.4 [1.2 to 1.5]                          2.2 [1.7 to 2.7]
                   2 Mac 1 h        1.3 [1.2 to 1.5]                          2.9 [2.2 to 3.5]
                   1 Mac 4 h        1.3 [1.1 to 1.5]                          2.5 [1.9 to 3.3]

Table 1. Pressure drop and penetration values for the different filters measured at 15 L min-1. Values are median
[range]. 'Group' had no effect on penetration (p = 0.05 for Hygrobaby; p = 0.92 for Hygroboy) after allowing for
the effect of pressure drop on penetration.

Discussion: This study demonstrates that the use of two common paediatric anaesthetic BSF (Hygroboy and
Hygrobaby) if used up to 4 hours and not exceeding 2 MAC sevoflurane do not have a statistically significant
reduction in filtration performance. However, further research is required at different flow rates, for different volatile
agents and for other commonly used paediatric breathing system filters.

Conclusion: Exposure to sevoflurane appears to have no effect on reducing the penetration and hence reducing
the filtration performance in certain electrostatic paediatric breathing system filters.

References:
1 British Standards Institution (BSI). Breathing system filters for anaesthesia and respiratory use part 1: salt test
method to assess filtration performance. BS EN 13328-1:2001. London: BSI, 2001.
2 National Institute for Occupational Safety and Health (NIOSH). Code of Federal Regulations, Title 42, Part 84.
Morgantown, West Virginia, USA: NIOSH, 1995.
3 Wilkes AR. The effect of volatile anaesthetics on the filtration performance of breathing system filters. British
Journal of Anaesthesia 2005; 95: 577P.
4 Malan CA, Wilkes AR, Gildersleve C. An evaluation of the filtration performance of paediatric system filters using
sodium chloride particles at low flows. Abstract presented at APA Annual Scientific Meeting, Cardiff, 2006.
                       AUDIT OF ROUTINE PRE-OPERATIVE COAGULATION TESTING

E. Fernandez, R. Self, M. George, A. Black Great Ormond Street Hospital London

Introduction. Routine coagulation testing is frequently performed before elective surgery. However these
tests have a poor positive predictive value in determining bleeding risk and may be within normal range
in the presence of disordered haemostasis (1). In addition, a child with abnormal coagulation test results
may need additional investigation and have his or her operation delayed.
There is limited evidence to guide practice. In paediatric patients, it may be more difficult to obtain a
history of bleeding disorder than in adults. Neonates and younger infants may not have been subjected
to a haemostatic challenge so an underlying bleeding disorder may not be clinically apparent. Values for
coagulation tests vary with both gestational and postnatal age of the infant (2-4). Most haemostatic
parameters reach adult values by the age of six months in a healthy infant.
In a review of both adult and paediatric literature, Chee and Greaves suggested that selective laboratory
testing following clinical assessment is preferable to routine pre-operative coagulation testing (1).
A prospective multicentre study of 1479 children undergoing tonsillectomy showed a relationship between
intra-operative bleeding (subjective assessment by surgeon) and abnormal pre-operative coagulation tests
(5). However, abnormal APTT and PT did not predict post-operative bleeding. The study also failed to
show a relationship between clinical history of bleeding and abnormal coagulation tests.

Objectives. The aim of this audit is to determine the incidence of abnormal pre-operative coagulation
tests in paediatric patients and the frequency of cancellation or delay of elective surgery as a result of
abnormal tests. The secondary aim is to determine what further investigations or therapies are required
in these paediatric patients.

Methods. Retrospective case note review of patients booked for elective maxillofacial, craniofacial or
spinal surgery found to have abnormal peri-operative coagulation tests over a six-month period.

Results. Of all the patients having surgery in those specialities in the first six months of 2006, 80 had
abnormal peri-operative PT, APTT, TT or fibrinogen. Of those, 21 had abnormal pre-operative coagulation
data. Of these group of 21: two patients had abnormal test results due to a contamination of the
sample with heparin; on haematology advice two patients had pre-operative FFP transfusion; further
investigations, mainly coagulation factor essays, were performed in eight patients and were abnormal in
five; two patients suffered a delay in surgery but no patients were cancelled.

Conclusions. The number of paediatric patients with abnormal routine pre-operative coagulation tests is
small. In only a small proportion of these patients further investigations revealed coagulation factors
deficiencies. The clinical significance of this is unclear. Although abnormal pre-operative clotting is not a
common cause for delay or cancellation of surgery it causes significant disruption for patients and
theatre efficiency. There is no evidence for performing routine pre-operative coagulation tests in
paediatric patients without a relevant medical history.

References
1 Chee YL, Greaves M. Role of coagulation testing in predicting bleeding risk. Hematol J 2003; 4(6):
   373-378.
2 William MD, Chalmers EA, Gibson BE. The investigation and management of neonatal haemostasis
   and thrombosis. Br J Haematol 2002 Nov; 119(2):295-309.
3 Andrew M, Paes B, Milner R et al. Development of the human coagulation system in the full-term
   infant. Blood 1987 Jul; 70(1): 165-172.
4 M, Paes B, Milner R et al. Development of the human coagulation system in the healthy premature
   infant. Blood 1988 Nov; 72(5): 1651-1657.
5 Gabriel P, Mazoit X, Ecoffey C. Relationship between clinical history, coagulation tests, and
   perioperative bleeding during tonsillectomies in pediatrics. J Clin Anesth 2000 Jun; 12(4): 288-29
   TWO DIMENSIONAL ULTRASOUND IN CLINICAL PRACTICE; A POSTAL SURVEY OF CONSULTANT
                   PAEDIATRIC ANAESTHETISTS IN THE UNITED KINGDOM

A. Walker, A. Waterfield, S. Roberts. Royal Liverpool Childrens Hospital, Alder Hey, Liverpool L12
2AP

Introduction: In September 2002, the National Institute for Clinical Excellence (NICE) produced
guidelines recommending the use of ultrasound guidance for elective insertion of central venous
catheters (CVCs) in children (1). These recommendations are now well known and reports
indicate that the majority of paediatric anaesthetists working in the UK have access to and are
routinely using ultrasound to place CVCs (2). Our question was, has this new and widespread
availability of ultrasound influenced its use in other areas of anaesthetic practice?

Methods:       Questionnaires were sent to all the UK members of the Association of Paediatric
Anaesthetists. Members were questioned on availability and clinical uses of ultrasound.

Results:
A total of 261 questionnaires were returned, a response rate of 62.5%. Ninety four percent
(n=244) of members have access to an ultrasound machine and seventy seven percent (n=201)
use ultrasound when inserting CVCs. Only 11.5% (n=30) of clinicians use ultrasound for
peripheral venous access and 13.4% (n=35) for arterial access. Eight percent (n=20) of
responders are using ultrasound to assist in placement of neuroaxial blocks, mostly caudals.
Fifteen percent (n=40) of members use ultrasound for peripheral nerve blockade with the
brachial plexus being the most popular technique.

Conclusions: Since the introduction of NICE guidelines use of ultrasound has become accepted
practice for CVC insertion amongst the majority of UK paediatric anaesthetists.        As a
consequence of this ultrasound technology is now far more accessible and although it has yet
to have been incorporated on a widespread scale into other areas of anaesthetic practice we
predict that this will change within the next few years.

References:
1. National Institute for Clinical Excellence. Guidance on the Use of Ultrasound Locating Devices
for Placing Central Venous Catheters. Technology Appraisal Guidance No 49, September 2002,
http://www.nice.org.uk 2002.
2. Bosman M, Kavanah RJ. Two dimensional ultrasound guidance in central venous catheter
placement; a postal survey of the practice and opinions of consultant paediatric anaesthetists in
the United Kingdom. Paediatr Anaesth 2006; 16: 530-537.
SURVEY OF VIEWS AMONGST ANAESTHETISTS AND ANAESTHETIC NURSES ABOUT INTERVENTION IN
                        CHILDREN FOR ELECTIVE PROCEDURES

R Pollard, Nuffield Department of Anaesthetics, John Radcliffe Hospital, Oxford

Introduction
The use of physical restraint for induction of children for anaesthesia is mostly a product of the
anaesthetist, the child, the surgery needed and the parents response. A standard recipe is
impossible considering all these variables. However the RCN has produced guidelines on the
use of restraint of children for invasive procedures to help clarify when and how it should be
applied.

Method
We asked the anaesthetists in our department by means of a paper questionnaire what they
would do in particular circumstances when faced with a difficult situation. We also asked similar
questions of the anaesthetic nurses in the operating room.
The response rate from the consultant anaesthetists was 33/60. The response rate for the
nurses was 13/30.

Results
Only 50% of nurses and none of the anaesthetists had knowledge of the RCN guidelines. Most
staff had not had any training in restraint of children. All the nurses but only 50% of
anaesthetists would appreciate some form of training in this aspect of treatment.
Anaesthetists and nurses estimated that 25-50% of children can be uncooperative at induction.
Anaesthetists were more open to use of restraint in older children, in contrast anaesthetic
nurses were more reluctant to use physical restraint. Anaesthetists were more inclined not to
cancel the case if the child did not cooperate, and consider physical restraint by parents or
staff.

Conclusion
This audit has established a base line of thought, knowledge and practice of the restraint of
children for induction of anaesthesia in our hospital.
It shows that the RCN guidelines for restraint of children are not widely known, and that both
anaesthetists and anaesthetic nurses have had little discussion and training in the aspect of
restraint.
It also shows importantly that nurses are less willing to use restraint than anaesthetists, and
this may lead to conflict and criticism in the workplace environment. Open discussion of this
subject is necessary amongst those who work with children.
There is however agreement on an overall approach, such that holding of older children is
deemed not appropriate for elective patients. Holding is considered more acceptable for
younger children.

References
    1) Thomas J. Brute Force or Gentle Persuasion? Paediatric Anaesthesia, 15, 355-357
    2) Christiansen E, Chambers N. Induction of anaesthesia in a combative child; Management
        and issues. Paediatric Anaesthesia 2005 15:421-425
    3) Restraining, holding still and containing children and young people. RCN Guidelines 2003
 AUDIT OF THE USE OF INTERVENTION FOR INDUCTION OF ANAESTHESIA IN ELECTIVE PAEDIATRIC
                                   DENTAL SURGERY

R Pollard, S Berg, Nuffield Department of Anaesthesia, John Radcliffe Hospital, Oxford.

Introduction
Children are referred for dental treatment under general anaesthesia because of failed
treatment under local anaesthesia. These children are a potential challenge to the anaesthetist,
since they have often developed a negative attitude towards dentistry and can be
uncooperative. Medical treatment of the non cooperative child for an elective procedure requires
understanding and cooperation between the parents, doctors, dentists, and nurses involved in
caring for that child. (1,2) The rights of the child must be considered where the use of
intervention is deemed necessary (3). Intervention may be either chemical or physical.

Methods
A prospective audit of intervention was collected over 33 operating sessions by two       consultant
paediatric anaesthetists. The data collected included the childs age, previous medical     or dental
experiences, specific fears of the children concerned, method and place of induction      (trolley or
parents lap), and personnel involved in holding. The approach to intervention was as      according
to the RCN guidelines.

Results
Data was collected for 148 children, of whom 28 needed some form of intervention (20%).
Ages ranged from 2-14yrs, and weight ranged from 15-60kg.
A need for intervention was anticipated preoperatively in 15 of the patients. The other 13
patients became uncooperative when entering into theatre, and the plan of restraint was
discussed when this became apparent.
Thirteen of the patients had no past significant history to indicate that they would be especially
worried about treatment. The remaining 15 patients had past history indicating that treatment
had been unpleasant.
Four of the children were given midazolam orally preoperatively.
Parents held their child in 27 of the cases, the 1 remaining case the staff restrained the childs
hand for cannulation. Staff assisted parents in holding in 19 of the cases.
Fifteen children were held on the parents lap, 13 of them were anaesthetised on the theatre
trolley.
All parents were satisfied with the childs management when questioned postoperatively.

Conclusion
Twenty five percent of children on this paediatric dental list needed some form of restraint for
induction of anaesthesia. This can be achieved carefully after discussion with the parent to
achieve satisfactory completion of elective dental work.

References
   1) Thomas J. Brute Force or Gentle Persuasion? Paediatric Anaesthesia, 2005; 15, 355-357
   2) Christiansen E, Chambers N. Induction of anaesthesia in a combative child; Management and
      issues. Paediatric Anaesthesia 2005; 15:421-425
   3) Restraining, holding still and containing children and young people. RCN Guidelines 2003
                   PERIOPERATIVE MANAGEMENT OF BLADDER EXTROPHY IN THE NEWBORN

L. Evans, R. Vashisht, Manchester Childrens Hospital, Hospital Road, Pendlebury, Manchester M27 4HA

Introduction: Bladder extrophy is a rare congenital defect with an incidence of 1:30,000 to 50,000 live births with a
slight male preponderance1. In early embryonic life, abnormal mesodermal movement in the infraumbilical area
prevents midline fusion of musculoskeletal elements. This leads to the absence of the rectus abdominus muscle,
anterior bladder wall and a pelvic diastasis. The remaining posterior bladder wall is everted and open from the
urinary meatus to the umbilicus. Initial closure of the defect involves major surgery in a neonate including anterior
or posterior pelvic osteotomy. Only a few centres in the UK undertake this surgery. Data regarding practice
standards for the anaesthetic management of such cases is lacking

Aim: Assess perioperative management and identify anaesthetic techniques that improve patient outcome and
reduce morbidity.

Method: Hospital Audit Committee approval was obtained to review case notes of patients having undergone
surgery for bladder extrophy since 2002. Data collected related to age at the time of surgery, post-conceptual age
(PCA), sex, anaesthetic technique, invasive monitoring, , pain and postoperative management and complications.

Results: Between January 2002 and August 2006, 20 patients had bladder extrophy repair at our institution. Only
19 case notes could be reviewed. Of these there were 9 females, 10 male patients1. PCA at time of operation
was 38-51weeks (mean 40.15 3.27wks); actual age was 1-78 days (median 3 days old). Duration of the procedure
was 4.5-12 hours (mean 6hrs 37m 1hr 47m). Anaesthesia in all the patients was induced and maintained using
Oxygen, air, Sevoflurane and they were intubated using Atracurium. Invasive arterial blood pressure was monitored
in 68% and internal jugular venous access was obtained in 68% of the patients. Remifentanil infusion was used
introperatively in 11 patients. Sixteen patients had caudal catheters inserted, in two patients there was failure in
siting the caudal catheter and one patient had an epidural catheter. Fentanyl was used to supplement analgesia in
3 patients with another 3 required Morphine boluses intraoperatively. The dose of caudal L.bupivacaine was 0.242-
0.93mg/kg/hr (mean 0.47 0.163mg/kg/hr). Caudal catheters were left in situ for 12-72hrs (mean 41.58 15.96hrs) 2,
3, removal of the catheter was not recorded in 3 patients. The highest temperature intra operatively was 35.6-
38.50C (mean 37.4 0.810C) and the lowest intraoperative temperature was 32.2-37.00C (mean 35.4 1.150C).
Postoperatively, 17 patients were managed on PICU and 2 patients on HDU. 16 patients were extubated
postoperatively in theatre with one patient needing reintubation on PICU. The maximum stay on PICU was 4 days.
Three patients required postoperative sedation with Morphine and Midazolam. They were still intubated or had
been reintubated. Three other patients received only Morphine infusion and 2 of these had no regional analgesia
and were receiving infusions for postoperative pain relief. Complications consisted of 2 patients developing
intraoperative hypothermia <340C, and 1 patient needing reintubation on PICU due to bradycardias and
desaturations. Two patients needed repeat surgery due to dehiscence of the repair. Total length of hospital stay
was 24 -51 days (mean 30.84 6.6 days).

Discussion: Surgical repair of Bladder Extrophy carries a high risk of morbidity and is resource intensive4. To
achieve urinary continence surgical management has evolved over time. Intensity of postoperative care and pain
management is primarily based on the surgical techniques used. At our institution, bilateral osteotomies and
postoperative leg traction is used to achieve closure of the pelvic ring. The results presented indicate the need for
an intensive care setting in the immediate postoperative period. Most of the patients were managed extubated
with a caudal catheter in situ without the need for any opiate or sedation after the first 48 hrs5.

References:
     1. Ben-Chaim J, Steven SG, Jeffs RD et al. Bladder extrophy from childhood into adult life. Journal of the
         Royal Society of Medicine.1996; 89:39-46.
     2. Hammouda HM, Kotb H. Complete primary repair of bladder extrophy: initial experience with 33 cases.
         The Journal of Urology.2004; 172:1441-44.
     3. Brown TCK, Eyres RL, McDougall RJ. Local and regional anaesthesia in children. BJA; 1999:65-77.
     4. Nelson CP, Dunn RL, Wei JT et al. Surgical repair of bladder exstrophy in the modern era: contemporary
         practice patterns and the role of hospital case volume. The Journal of Urology.2005; 174:1099-102.
     5. Kost-Byerly S, Jackson EV, Schwengel DA et al. Perioperative anesthetic management of newborn bladder
         exstrophy repair. Anesthesiology 2004; 101:A1472.
   CURRENT PRACTICE OF END-TIDAL CARBON DIOXIDE MONITORING AMONG ANAESTHETISED
                       PAEDIATRIC PATIENTS- REPORT OF A SURVEY

K Raghavan, M Shankar Hari, J Pook, Department of Anaesthesia, University Hospital Lewisham,
London.

Background: End-tidal carbon dioxide monitoring provides us with valuable information about
patients airway, lung mechanics, cardiac output, pulmonary blood flow and more. The
measured ETCO2 may not accurately represent the actual ETCO2 in paediatric patients due to
either patient factors or equipment related factors.
To further understand practice in measuring and interpreting ETCO2 in anaesthetized paediatric
patients, we conducted this survey with the help of members of Association of Paediatric
Anaesthesia. We also looked into the current practice of monitoring and other related
equipment use, the knowledge applied into the practice and presence of any innovative or
novel methods of making measured ETCO2 a more accurate reflection of actual ETCO2.

Methods: After obtaining due permission, the questionnaire was circulated via email to
members of the APA with best efforts to maintain confidentiality. A total of 448 were sent of
which 98 were to non-UK based members.
The data from the responses were collected and analysed using Microsoft Excel. We analysed
the responses for two groups of children; small children (weighing less than 5 kg) and larger
children (weighing from 5-20kg.)

Results: This abstract is based on the first 30 responses; the presentation will be based on
over a 100 responses. Most of our respondents accept a different range of end-tidal CO2 in the
smaller children than those larger children (3-8kPa vs 4-10kPa). This will be discussed in the
presentation. ETCO2 is always monitored in an anaesthetized child, mostly using a sidestream
capnometer, with gas flows mostly greater than 100 ml/min and less than 300ml/min. The
sample is obtained at the filter most commonly. Most of the paediatric anaesthetists believe
that the measured ETCO2 is inaccurate by 10 to 30% as compared to the actual ETCO2 mostly
by experience. Evidence includes the use of arterial blood gas analyses and/or transcutaneous
carbon dioxide monitoring. Less than 40% of the responders are aware of the availability of an
endotracheal tube with an inbuilt sampling line for ETCO2 monitoring. Amongst the ones who
are aware about 40% use these tubes in their practice.
The most commonly used breathing system for spontaneous ventilation in smaller children
(<5kg) is Jackson Rees modification of Ayres T piece. In larger children circle system is most
commonly used for both spontaneous and mechanical ventilation. Circle is also used by most
in ventilating smaller children. While facemasks are used for spontaneously breathing smaller
children, LMAs are used in the other group. Endotracheal tubes are used during mechanical
ventilation in both the groups most of the times, pressure control mode being the commonest
mode of ventilation.

Conclusion: Despite the fact that the members of APA are spread across the globe, the practice
of ETCO2 monitoring and interpretation, seems to be quite uniform. After this survey, we are
still left with the question as to how to make the measured ETCO2 more accurate. Is the
endotracheal tube with inbuilt sampling line of any help? Do we have to rely on
transcutaneous CO2 or arterial blood gas measurement? Are cuffed endotracheal tubes and low
flow capnometers better for the above purpose?