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 firstname.lastname@example.org, 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 . 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 . 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 . The LIP is regarded as the opening pressure of collapsed lung units and the target of „best PEEP‰ . The UIP is regarded as the pressure at which alveolar distension occurs; it therefore defines the upper limit of pressure during mechanical ventilation . 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 . 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 . Studies have shown that increasing the information available to parents may lessen anxiety [1, 2]. One source of such knowledge is information leaflets . 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 . Studies show that parents prefer to have more information and giving such information does not increase anxiety levels . 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 . 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 . 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?
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