Hamilton Anaesthetic Website by liaoqinmei

VIEWS: 14 PAGES: 70

									ACKNOWLEDGEMENT


This 1st Edition of the Waikato DHB Inpatient Pain Service Pain Management
Handbook for adult patients has been greatly assisted by having access to the Otago
DHB’s Acute Pain Guidelines as a template to guide the development of this
organisation’s document. The Otago Acute Pain Guidelines were primarily written by
Dr David Jones, Specialist Anaesthetist and Director of the Pain Management
Services, Otago DHB. I extend my thanks to him for allowing us to utilise his
document in the process of compiling our own.



Sue King
CNS
Inpatient Pain Service
July, 2010




Disclaimer: This material is designed as a guide only for the care of adult patients at
Waikato Hospital. It does not replace decisions tailored to individual patients by the
clinicians responsible for their care. No responsibility is taken for factual errors.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 2 of 70
TABLE OF CONTENTS


Acknowledgement....................................................................................................... 2
1.0Introduction to the Inpatient Pain Service Handbook ............................................ 4
1.1Referral to the Pain Services ................................................................................ 5
1.2Requirements of the Inpatient Pain Service .......................................................... 6
2.0Basic Principles of acute pain management .......................................................... 8
2.1Drugs used in acute pain management................................................................ 10
3.0 Methods of opioid administration......................................................................... 18
3.1 Titration of IV opioids for acute pain control in adults algorithm ......................... 20
3.2 Patient-Controlled Analgesia.............................................................................. 21
4.0Regional Analgesic Methods, Epidural Infusion Analgesia ................................. 28
4.1 Interpleural & Paravertebral Analgesia............................................................... 35
4.2 Peri-neural Analgesia ........................................................................................ 40
5.0 Inhalational analgesia ......................................................................................... 44
5.1 Nitrous Oxide (Entonox)...................................................................................... 44
5.2 Methoxyflurane.................................................................................................... 44


Appendix I
Acute pain: adverse physiological and psychological effects                                ........................ 49
Appendix II
Opioid Conversion Table........................................................................................... 52
Appendix III
PCA Pump drug library protocols.............................................................................. 53
Appendix IV
Troubleshooting Guidelines. ..................................................................................... 54
Appendix V
Guidelines for the treatment of Nausea and Vomiting .............................................. 55
Appendix VI
Anticoagulation and epidural anaesthesia................................................................. 57
Appendix VII
Ketamine/midazolam for ward based procedures .................................................. 59
Appendix VIII
Acute pain management in the opioid-tolerant patient .............................................. 63
Appendix IX
Acute neuropathic pain ............................................................................................ 66
Appendix X
Neuropathic screening tools...................................................................................... 69
References/resources............................................................................................... 71




                                                                               st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010              Page 3 of 70
1.0 Introduction

The purpose of this handbook is to help hospital staff manage severe pain in adults. It
provides guidance about techniques routinely available in Waikato Hospital. It is not a
comprehensive guide to pain management and it is not intended to dictate the way
individual clinicians practice. The handbook is written by the Waikato Hospital
Inpatient Pain Service (IPS) which is part of the Department of Anaesthesia. The IPS
hopes that the handbook will lead to a more consistent and coordinated approach to
pain management across the DHB. The major focus is severe acute pain, however,
the IPS provides a consultative service for inpatients with chronic and cancer pain.

The IPS operates within a collaborative care model. The ultimate responsibility for the
patients care rests with the primary medical team.

The role of the IPS varies depending on the situation for example:

              •   Management of acute pain following surgery or trauma with advanced
                  analgesic techniques e.g. Epidural analgesia, other regional analgesia,
                  PCA, ketamine infusion. In general the IPS will be responsible for all
                  aspects of these analgesic techniques i.e. commencement, titration,
                  problem solving, transition to oral analgesia.
              •   Assistance with the management of acute on chronic pain, neuropathic
                  pain, and cancer pain with oral analgesia.
              •   Assistance with the management of pain in patients with complex pain
                  related issues e.g. pain in patients on the methadone maintenance
                  programme.
              •   Assistance with the management of patients admitted with long term
                  interventional pain techniques e.g. intrathecal catheters.
              •   Consultation and assessment of patients that may need referral to the
                  Chronic Pain Clinic or to the Interventional Pain Procedure Clinic.
              •   Ongoing education of medical and nursing staff.
              •   Standardisation of protocols, procedures, and dosage regimes.
              •   Accurate record-keeping and maintenance of an inpatient pain service
                  database.

The IPS conducts a ward round each morning on weekdays and at weekends. During
these ward rounds patients are assessed for effectiveness of pain relief and for any
adverse effects of treatment. Any changes required to the acute pain management
regime are made in consultation with the ward medical and nursing staff caring directly
for the patient. The general pattern of staffing the IPS is:

    •    During weekday normal working hours - A Consultant Anaesthetist and/or
         Anaesthetic Registrar, plus a Clinical Nurse Specialist.
    •    After hours the On-call Anaesthetic Team covers the IPS service.

At any time during the day or night the IPS may be contacted about any patients with
acute pain problems being cared for by the IPS — see “Referral to the Inpatient Pain
Service’.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 4 of 70
1.1 Referral to the Inpatient Pain Service (IPS)

    a) Referral from the operating theatres

Severe post-operative pain is the commonest reason to refer a patient to the IPS.
Most referrals are made by the attendant anaesthetist using the ‘pink form system’.

If Post Anaesthetic Care Unit (PACU) staff believe a patient would be suitable for IPS
care but the patient has not been referred by the attending Anaesthetist, it is best to
contact the Anaesthetist involved first. If he or she is not available, the Duty
Anaesthetist is to liaise with the surgical team.

    b) Referral from the wards an other inpatient areas.

All ward referrals should be made directly to the IPS by a medical staff member of the
patient’s primary medical team. The IPS cannot accept medical referrals from ward
nursing staff.
    -      The IPS nurse may be used as the point of contact, when making the
           referral.
    -      Sometimes advice given over the phone is all that is required.
    -      The IPS has a specific referral form (see intranet – Pain Services). In most
           cases it will be necessary to fill out this form, scan it to xxxx and leave the
           original in the front of the patient’s notes, or deliver to the original to L3
           PACU, Kempthorne theatres.

Before referring a non-surgical patient to the IPS the referrer must check that the
primary medical team consultant is aware of, and supports, the referral.

For urgent referrals always contact the IPS by phone first.

IPS Commencement Procedures (for anaesthetic/IPS staff)

1) IPS Referral Form:                          Complete form with patient’s name and ward. Place
                                               either in appropriate ward section of the IPS folder
                                               or in the basket in Level 3 PACU. All details need to
                                               be included at this time.

2) Advanced Analgesic                          Make sure charting is completed accurately
   Techniques:                                 according to IPS guidelines/drug protocols.

3) Simple Analgesia:                           Ensure simple analgesia is accurately charted.

4) Check other drug charts:                    For drugs interactions involving analgesic regimes.


IPS Discharge Procedures

IPS Discharge: Document discharge from IPS in patient’s notes as part of daily IPS
entry.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 5 of 70
Cessation of Epidural: Sign off epidural infusion order on cessation of epidural. Make
sure the time/date that the catheter is to be removed is clearly documented in the
patient’s notes, and the ward nurse informed.

1.2 Requirements of the Inpatient Pain Service:

The IPS aims to function together with the patient’s primary medical team and the
ward staff as a team. For continuity, record-keeping, absence of confusion, and ease
of operation, the following should be adhered to where possible:
    • At any time during the day or night the IPS MUST be informed about any
       significant complications or side effects relating to pain treatment a patient is
       receiving, provided he or she has previously been referred to and followed up
       by the IPS
    • Please notify the IPS before discontinuing any pain treatment being managed
       by the IPS
    • Patients whose advanced analgesia regime is altered without consultation with
       the IPS will be assumed to have been withdrawn from IPS care, and the IPS
       will not accept further responsibility for that patient.
    • No changes to PCA/Epidural prescriptions should be made unless there has
       been prior consultation with an anaesthetist/IPS
    • All pain service infusion pumps must be cleaned and returned to PACU
       (epidural pumps) or Central Equipment Pool (PCAs) as soon as treatment is
       discontinued to allow for the best use of the pumps
    • Patients who are referred to the IPS should NOT receive any additional
       opioids or other analgesics/sedatives (including night sedation, TCA,
       gabapentin, antihistamines) without prior consultation with the IPS to avoid
       potentially serious drug interactions and adverse events

Ward Medical Staff Role:

Collaboration is encouraged between the ward medical staff caring primarily for the
patient and the IPS staff.

Consultation about patients and their pain is both to ensure efficacy of prescribed
analgesia and also to raise awareness of potential drug interactions relating to
concurrent administration of medical and analgesic medications. The IPS does not
wish to interfere with patients’ medical management, but on occasions consultation is
essential as drugs administered by the IPS may have various effects on the well-being
of the patient.

The IPS is available to suggest and advise on other anti-emetics if nausea and/or
vomiting persist after following the IPS regimes suggested, or for advice on the
minimization of constipation.

Ward Nurse’s Role:

The role of the ward nurse is vital to the appropriate management of patients in pain.
The nurse caring for the patient is in the best position to assess the patient’s need for
analgesia and to effectively manage the patient for optimum comfort, as well as the
early recognition of potential complications related to pain management.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 6 of 70
Effective and safe pain relief can be achieved through:
    • close observation, regular recording of patients’ cardiorespiratory parameters
        and intelligent interpretation of same
    • accurate documentation of volumes of drugs infused
    • documentation of sedation scores
    • assessment and documentation of pain, both at rest and on movement/with
        activity.

     Note: Patients should have no more than mild pain at rest and be able to
     participate in rehabilitation/recovery activities without pain preventing them from
     doing so.

This may result in a more rapid recovery for the patient and fewer complications.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 7 of 70
2.0 Basic Principles of Pain Management

          •    Comprehensive pain assessment using a structured approach with regular
               re-evaluation and adjustment of therapy

          •    Use combinations of drugs and techniques

          •    Optimise dose, frequency and route

          •    Treat side effects appropriately

          •    Provide calm reassurance

A significant degree of relief from pain can be obtained from optimal use of simple
techniques, and may involve the use of both non-pharmacological and
pharmacological approaches.

Although most patients under the care of the IPS will be managed with one or more
advanced analgesic techniques, optimal use of simple techniques still forms a
valuable adjunct to advanced pain relief therapies.

Optimal use of analgesics:

Simple analgesic drugs and techniques can produce a significant degree of analgesia
if used appropriately. The following are some simple guidelines, which can be used to
enhance the effectiveness of simple analgesic regimes.

    1. Relief of anxiety, fear, and apprehension by discussion with patients (and their
       relatives) and providing explanation and reassurance may significantly enhance
       an analgesic regime

    2. Use simple analgesics at maximum doses before adding stronger analgesics

    3. The oral route of administration should be avoided in patients with persistent
       nausea and vomiting

    4. PCA is the safest way to give strong analgesics in the severe pain setting

    5. Effective analgesia requires attention to and effective treatment of the side
       effects of analgesic therapy (e.g. nausea and vomiting, constipation, urinary
       retention, pruritus, dehydration)

    6. In patients with high opioid requirements (≥ 100mg oral morphine/day), slow
       release background oral opioid and rapid release option should be charted for
       “rescue”




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 8 of 70
Monitoring patients being treated for pain:

Assessment and recording of patient’s pain as the “fifth vital sign” is promoted as an
integral component of acute pain management, and one that is routinely carried out in
association with other measurements such as respiratory rate, blood pressure, pulse
and temperature. Monitoring of patients receiving analgesia, especially when it
includes strong opioids or other sedative adjuncts such as gabapentin or TCAs, is
essential to ensure effective analgesia and early recognition and/or minimisation of
complications associated with treatment.

1.       Pain Score:

There are a range of different scoring systems/scales to evaluate the intensity of
patients’ pain. At Waikato Hospital, we use the VNRS.

Verbal numerical rating scale (VNRS)

No pain I ----- I ----- I ----- I ----- I ----- I ----- I ----- I ----- I ----- I ----- I     worst pain
   0     1       2       3       4       5       6       7       8       9      10            imaginable

An alternative to the VNRS, is the descriptor scale – “nil”, “mild”, “moderate”, “severe”,
or “excruciating”, or the Faces scale for cognitively impaired adults.

Assessing pain in patients who speak little or know English can be difficult if an
interpreter is not readily available. To assist on these infrequent occasions, each
ward/unit has a flip chart for assessing pain translated into a number of different
languages.

Increasing sedation is a more reliable, and usually early, warning sign of evolving
opioid overdose than respiratory rate (Macintyre & Scott, 2009). Waikato Hospital
uses the following scale to measure degree of sedation and rousability:

                  0      =      none
                  1      =      mild — occasionally drowsy, easily roused
                  2      =      moderate — frequently drowsy, easily roused
                  3      =      severe — somnolent, difficult to rouse
                  S      =      normal sleep, easy to rouse
                  N.B. If patient asleep — please chart “S” on the Observation Chart if all
                  other observations are normal.

Reliability of SpO2 monitoring

As an indicator of respiratory depression, oxygen saturation monitoring is not a
reliable measure of respiratory drive. In addition, if the patient is receiving
supplemental oxygen, this may mask deterioration in respiratory function, because
“normal” saturations may be seen even if there is little evidence of respiratory
depression (Macintyre & Scott, 2009)




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010       Page 9 of 70
2.1 Drugs used in acute pain management (see also drug guidelines on Waikato
Hospital intranet under Anaesthesia)

Non-opioids:

Paracetamol

Effective non-opioid analgesic and antipyretic. Mechanism of action remains unclear.
Does not inhibit peripheral cyclo-oxygenase activity. There is increasing evidence for a
central antinociceptive effect.
Important basic analgesic drug in acute post-operative pain management. Single doses
are effective. Used regularly is also an effective adjunct to opioid analgesic with 20–30%
opioid sparing effect. Caution needed if patient has a history of heavy alcohol intake or
pre-existing liver disease, and in patients who are malnourished. Otherwise it has a
highly favourable risk: benefit ratio and can be considered as a near-routine post
operative background analgesic.
Available:
Oral/rectal 1 g q 4-hrly PO/PR adults (maximum 4 grams in 24 hours).
Intravenous (IV) 500 mg and 1 gram (IPS/Anaesthetist/ICU prescription only).

non-selective Non-Steroidal Anti-Inflammatory Agents (nsNSAIDs):

Analgesic, anti-inflammatory, and antipyretic effects. NSAIDs are effective in a variety
of acute pain settings including pain after minor and major surgery. Given in
combination with opioids, NSAIDs produce better analgesia and reduce opioid
consumption by 25–50% after surgery, and opioid related side effects such as nausea
and vomiting.
NSAIDs given in addition to Paracetamol improve analgesia.
NSAIDs are an integral component of multimodal analgesia.
Contraindications and significant adverse effects limit use.
Side effects are more common with long-term use. In the perioperative period the
main concerns are renal impairment, interference with platelet function, peptic
ulceration, and bronchospasm in individuals who have aspirin-exacerbated respiratory
disease.
In general, the risk and severity of NSAID associated side effects are increased in
elderly people.
Bone healing: There is no good evidence that any inhibitory effect NSAIDs have on
bone healing is clinically important. More studies are required (Bandolier, 2004).

nsNSAIDs and interactions with other drugs

NB. Patients on other medications affecting renal function such as ACE
inhibitors, IV radiocontrast media and antibiotics such as the aminoglycosides
may be at more risk of adverse effects on the kidney. If use is considered,
please monitor U+Es closely and use for the shortest time possible at the
lowest effective dose. If unsure, please consult a member of the IPS for advice.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 10 of 70
Most commonly used nsNSAIDs in Waikato Hospital:

Diclofenac (Voltaren)
       2–3 divided doses. PO or PR.
       Usual max limit adults: 150 mg/day.

Ibuprofen (Nurofen, Brufen) tablets, capsules, elixir.
       1200 – 1800mg/day initially, 600–1200 mg usually for maintenance
       Can use in first 48 hours. 1200–2400 mg/day.
       3–4 divided doses.

Cyclo-oxygenase 2 selective inhibitors (COX-2 inhibitors/coxibs):

Selectively inhibit the inducible cyclo-oxygenase enzyme, COX-2, and spare the
constitutive enzyme, COX-1.
COX-2 inhibitors offer the potential of equally effective analgesia with advantages in
specific situations, especially short term in the perioperative setting.
COX-2 inhibitors do not impair platelet function.
It is appropriate to use COX-2 inhibitors over traditional NSAIDs when GI
bleeding/ulceration is a concern.
COX-2 inhibitors are the anti-inflammatory of choice after some types of orthopaedic
surgery, neurosurgery, liver surgery, and tonsillectomy where the anti-platelets effects
of traditional NSAID’s are unwanted.
Can be used in patients with aspirin-induced airway hyperactivity.

COX-2 inhibitors are contraindicated in patients with ischaemic heart disease,
hypertension, cardiac failure, renal impairment, diabetes, or who have had previous
strokes, and perioperatively in cardiac or vascular surgery.
Parecoxib 40 mg IV 24 hourly – reserved for perioperative use only and if used in the
postoperative setting, only IPS prescription permitted.

There are no COX-2 inhibitors in the Waikato Hospital formulary.
However Celecoxib (celebrex) and Meloxicam (mobic) can be sourced if prescribed.

Opioids:

Opioids remain the mainstay of systemic analgesia for the treatment of moderate to
severe acute pain, although opioid requirements vary greatly. Therefore, opioid doses
need to be titrated to suit each patient. In adult patients, age rather than weight is the
better predictor of opioid requirements.

Choice of Opioids:

All strong opioid agonists given in equianalgesic doses produce the same analgesic
effect, but such equianalgesic doses are difficult to determine due to interindividual
variabilities in pharmacokinetics and -dynamics (see Appendix II Opioid Conversion
Chart).

Available data does not suggest that any one strong opioid agonist is superior to
another; either in terms of better pain relief, differences in side effects, or patient


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 11 of 70
satisfaction, but rather that some opioids may be better in some patients. Therefore
the concept of opioid rotation is a useful strategy in the management of acute pain in
patients with intolerable opioid related side effects that are unresponsive to treatment.

NB. A regularly administered oral opioid (eg LA-morph BD) is the equivalent of a
continuous opioid infusion, so as patients’ pain subsides postoperatively, the
doses of strong oral opioids, such as morphine or oxycodone, will need to be
reviewed and adjusted regularly.

Information about specific opioids: -

Codeine:          is classified as a weak opioid but the molecule itself is devoid of
                  analgesic activity. The metabolism to morphine (2–10% of the dose
                  given), the minor metabolic pathway accounts for most of the analgesic
                  effect of codeine.
                  The enzyme responsible for the conversion to morphine is cytochrome
                  isoenzyme P450 (CYP) 2D6, which is lacking in about 10% of
                  Caucasians.
                  There is a ceiling effect. This results in the opioid side effects, nausea,
                  and constipation occurring without the benefit of potent analgesia offered
                  by strong opioids.
                  - Available as tablets for oral use. Dose: 30–60 mg PO q4-6 hrly prn.
                      Single oral dose 60 mg is not an effective analgesic. It is significantly
                      more effective when given in conjunction with Paracetamol.

Dihydrocodeine: is a semi-synthetic derivative of codeine but with an analgesic effect
            independent of its metabolism to dihydromorphine.
            - Available 60 mg slow release (SR) tablets. Dose 60–120 mg SR BD.
            - As slow release may take 3-4 hours to reach peak effect
            - Tend to only use if patient already on when admitted.

Oxycodone: is a semi-synthetic opioid agonist. Commonly used in acute pain
           management for patients able to take opioids by mouth. Useful for
           moderate to severe pain. Commonly used as a ‘step-down’ analgesia
           following patient-controlled analgesia (PCA) with doses based on (PCA)
           opioid requirements.

                  -    Twice as potent as oral morphine (i.e. 5 mg oral Oxycodone equals
                  10 mg oral morphine).
                  -     Available as immediate release (IR) (Oxynorm): 5, 10, & 20 mg
                  capsules. IR capsules 5–15 mg PO q4 hrly prn.
                  -     Controlled release (CR) formulation (Oxycontin): 5, 10 & 20 mg
                  tablets.

                  N.B. CR Oxycodone comprises an IR component as well as the
                  delayed release compound and therefore has a more rapid onset of
                  action than other CR agents.

Morphine:         Remains the most widely used opioid for the management of pain and
                  the standard against which other opioids are compared. Morphine 6-


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 12 of 70
                  glucuronide (M6G) and M3G, the main metabolites of morphine, are
                  formed by morphine glucuronidation primarily in the liver. M6G is a mu
                  opioid agonist and may have more potent analgesic effects than
                  morphine. M3G has no analgesic activity. It may antagonise the
                  analgesic effects of morphine and be responsible for neurotoxic
                  symptoms, such as hyperalgesia, allodynia, and myoclonus sometimes
                  associated with high doses of morphine. Both M3G and M6G are
                  dependent on the kidney for excretion.
                  Impaired renal function, oral route of administration, high doses and
                  advanced age are increased risk factors for accumulation of these
                  metabolites.
                  - Oral formulations: bioavailability 20–33%.
                  - Immediate release: q 1-2hrly prn.
                  -    Morphine elixir 1mg/mL usually used for break-through pain when
                  patient established on oral opioids.
                  - Morphine rapid release tablet (sevradol) 10 & 20 mg.
                  - Controlled release: q 8–12 hrly, and comes as LA-Morph CR tablets:
                  10, 30, 60, 100, 200 mg or m-Eslon capsules: 10, 30mg, 60mg, 100 mg
                  and 200mg for patients admitted to hospital established on this
                  formulation.

                  Intravenous Morphine Adults:

                  Available as 10mg/mL for titration/bolus dosing (See ‘IV Opioid Titration
                  algorithm for Acute Pain in Adults, pg )
                  Patient-controlled analgesia: Premixed polybags 100mg/100mL

Methadone: Commonly used for the maintenance treatment of patients with opioid
           addiction because of its good oral bioavailability (60–95%), high potency
           and long duration of action.
           In addition, its lack of active metabolites, low cost, and additional effects
           as an n-methyl-D-aspartate (NMDA) receptor antagonist and serotonin
           re-uptake inhibitor have led to its increasing use in the treatment of
           cancer and chronic non-cancer pain.
           Its use in acute pain treatment is difficult and limited by its long and
           unpredictable duration of action and risk of accumulation, so should only
           be prescribed by practitioners familiar with its complex
           pharmacodynamic/pharmacokinetic features, eg IPS, Palliative Care.

                  Available as:
                  Ampoule — 10 mg/mL for IV administration.
                  Tablets — 5 mg
                  Elixir — 2 mg/mL or made up to desired concentration.

Fentanyl:         Synthetic opioid and pure mu agonist. Commonly used opioid intra-
                  operatively. Is being increasingly used in the treatment of acute pain
                  because of its lack of active metabolites and fast onset of action.
                  The lack of metabolites makes it the drug of choice in patients with acute
                  or chronic renal failure.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 13 of 70
                  Available as:
                  Ampoule 100 mcg/mL for IV bolus administration
                  Prepacked 1000 mcg / 100 mL polybag for PCA use.

                  Transdermal Fentanyl Patch (TTS) commonly used in the management
                  of cancer and chronic pain. Due to the intradermal (reservoir) formation,
                  onset and offset times are very slow (eg takes 12 hours at least for
                  steady state), making short-term titration impossible. There is also
                  marked interpatient variability in blood concentrations reached. These
                  factors make TTS fentanyl unsuitable for acute patient management.
                  Can be used in selected situations in opioid tolerant patients.
                  Available as 12.5, 25, 50, 75, 100 mcg patches – respectively these
                  deliver 12.5mcg/hr, 25 mcg/hr, 50 mcg/hr, 75 mcg/hr and 100 mcg/hr.
                  Usually changed every 3rd day.

Pethidine:        A synthetic opioid still widely used even though it has multiple
                  disadvantages. Despite common belief, there is no evidence that
                  pethidine is better than morphine in the treatment of renal or biliary colic.
                  Accumulation of its active metabolite, norpethidine, is associated with
                  neuroexcitatory effects that range from nervousness to tremors,
                  twitches, multifocal myoclonus and seizures.
                  As norpethidine is renally excreted, renal dysfunction increases the risk
                  of norpethidine toxicity. Overall, the use of Pethidine is discouraged in
                  favour of more effective and less harmful opioids.

Tramadol:         Listed as a weak opioid by the World Health Organisation. However it is
                  commonly referred to as an atypical centrally-acting analgesic because
                  of its combined effects as an opioid agonist and a serotonin and
                  noradrenaline re-uptake inhibitor.
                  Risk of respiratory depression is lower at equianalgesic doses compared
                  with other opioids. In addition Tramadol causes less sedation, has
                  limited effects on gastrointestinal motor function, causes less
                  constipation and has less adverse effects on gastric emptying and post-
                  operative bowel recovery than morphine.
                  Nausea and vomiting occur at rates similar to other opioids. Tramadol is
                  an effective treatment of neuropathic pain.
                  Available as:
                  Capsule 50–100 mg q4–6 hrly prn (maximum 600mg/day)
                  Ampoule 100 mg / 2 mL. For intravenous administration
                  Either as a bolus use or via PCA.


Other Analgesics:

Ketamine

    Intravenous anaesthetic agent that has clinical useful analgesic activity at sub-
    anaesthetic doses.
    Action:   N-methyl-D-asparate (NMDA) receptor antagonist.
    Has opioid-sparing effect in post-operative pain.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 14 of 70
    May have preventative analgesic effects.
    Improves analgesia in patients with severe pain. Ketamine may be a useful adjunct
    in conditions of allodynia, hyperalgesia, and opioid tolerance.

Ketamine’s use is limited by side effects of unpleasant dreams and hallucinations that
occur with ketamine anaesthesia. These side effects are reported as zero to mild
when low-dose ketamine is used for analgesia, and can also be reduced with the
addition of low dose benzodiazepine such as midazolam.


Ketamine Infusions
     A labelled syringe driver pump should be used for ketamine infusions.
     Ketamine should be ordered on the APS Ketamine Infusion prescription chart,
     although sometimes an inpatient medication chart may be used depending on
     the individual situation.
     Standard dilution regime should be used: Ketamine: 200 mg diluted to 50 mL in
     saline in a 50 mL syringe (4 mg/mL).
     Usual doses range from:
     4–10 mg/hr (1–2.5 mL/hr) in younger patients to
     2–4 mg/hr (0.5–1 mL/hr) in the older patient.
     Sometimes smaller doses will be required.
     Doses up to 12 mg/hr have occasionally been used in patients.

Ketamine infusions can be ordered ‘IV/SC’. They may run in the same IV line as PCA,
but separate iv access is preferred, as ketamine is quite irritating to the subcutaneous
tissues when administered via this route. Should IV access be an issue, the addition of
a local anaesthetic such as lignocaine can reduced tissue irritation via subcut route.

Follow General Management protocol on IPS ketamine infusion prescription chart.

Clonidine

Clonidine is an alpha-2-adrenoceptor agonist that acts as an analgesic at the level of
the spinal cord.
Systemic administration (oral, IV), decreased perioperative opioid requirements in
surgical patients. Clinical usefulness may be limited by the high frequency of side
effects including sedation and hypotension.
IV use: titrated slowly in 15 mcg doses because of high frequency of bradycardia and
hypotension.

Preservative-free clonidine is used in combination with local anaesthetics to prolong
the duration of regional analgesic blocks (epidural and plexus blocks).
Transdermal continuous release patches are occasionally used by the IPS as an
adjunct analgesic in “complex” cases, eg. acute neuropathic pain.
Available as: TTS-1, TTS -2, TTS-3: 100, 200, and 300 mcg/day respectively.
Note: onset and offset times are slow.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 15 of 70
Calcitonin

As many as 75% of patients may report phantom limb pain within the first few days
after amputation (Nikolajsen et al, 1997).
Calcitonin by intravenous (IV) infusion is effective in the treatment of acute phantom
limb pain (Jaeger and Maier, 1992, Level II)probably via receptor-modulation of
serotonergic activity in descending pain pathways (Visser, 2005).
Treatment should start as soon as possible to prevent chronic pain. Informed consent
must be obtained.

    -    Dose: Calcitonin 100 mg in 100 mL saline via intravenous infusion pump over
         one hour. Can also be given subcutaneously, and may be better tolerated
    -    Frequency      — dose repeated for 3 consecutive days.
                        — can be repeated 1–2 x per year.

Contraindications: Salmon allergy or sensitivity.
Side effects: Flushing, hypotension, and nausea. All reduced by slow infusion, with the
administration of an antiemetic 30 mins before commencing each day’s infusion also
advised.
Analgesia: Onset comes on gradually over greater than one week and a good result
may last many months
Calcitonin has also been shown to be effective in the treatment of acute pain after
osteoporosis and related vertebral fractures (Blau & Hoehns, 2003, Level 1).

Gabapentin:

Gabapentin is an anticonvulsant that works as a Ca2+ channels antagonist, and
reduces neurotransmitter release (glutamate,aspartate, substance-P and calcitonin
gene-related peptide) leading to a reduction in neuronal hyperexcitability. It may also
antagonise glutamate receptors - NMDA and AMPA – reducing hyperalgesia and
allodynia which is part of wind-up and central sensitization.

Uses: Treatment of neuropathic pain.
       Has opioid-sparing effect in post-operative pain and may have preventative
       analgesic effects.
May be given preoperatively as a premedication or prescribed postoperatively for
certain types of surgery, eg thoracotomy.

Precautions:
   • Use reduced doses in patients with impaired renal function, on dialysis
    •    Avoid abrupt withdrawal of the drug
    •    Pregnancy – benefits must outweigh the risks of treatment, and ensure folic
         acid 5mg supplementation)
    •    Concommitant use of another AED
Side effects: sedation, fatigue, dizziness, headache, nausea




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 16 of 70
NB When gabapentin is prescribed in addition to opioid analgesia, it should be
anticipated that the opioid requirement will be reduced by up to 50%. Care should be
taken therefore when prescribing appropriate doses to reduce the risk of
oversedation/narcosis.

Funding – gabapentin is not funded outside hospital. If commenced for the treatment
of neuropathic pain, unless the patient has tried and failed on or not tolerated a TCA,
funding               will               not                be                approved.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 17 of 70
3.0 Methods of Opioid Administration

1. Parenteral administration

Intravenous administration is the best means by which severe acute pain can be
treated effectively. Small doses of opioid can be given repeatedly by a medical officer
or registered nurse/midwife but balanced against patient response/side effects. Time
to onset and time to peak is much faster via intravenous route than via subcutaneous
or intramuscular routes.

         Eg.      Morphine subcut/IM – onset = 15-20mins; peak = 60-90mins
                  Morphine IV        - onset = 3-5 mins; peak 15-20mins

(See pg 20 for IV Opioid Titration algorithm)

2. Patient controlled analgesia (see pages 21 - 27 for further information on PCA)

The term IV PCA or more commonly known as simply PCA refers to the method of
pain relief that allows a patient to self-administer small doses of an opioid analgesic as
required, via a programmable pump that delivers the opioid intravenously or if
intravenous access is scarce, subcutaneously. IV opioid PCA provides better
analgesia than conventional [intramuscular (IM), subcutaneous (SC)] opioid regimes,
and works well for incident-related pain.

3. Nurse Controlled Analgesia (NCA)

Nurse controlled analgesia takes the equipment and principles of PCA and puts
control for pressing the demand button in the hands of the registered nurse. NCA is
selected for those patients who are cognitively or physically impaired. The patient is
protected from over dose by routine observation and monitoring, which includes the
principle of “assess-intervene-reassess”.

4. Subcutaneous/intramuscular opioids

Intramuscular administration is rarely used now.
Subcutaneous administration - the usual drug is Morphine, although occasionally Fentanyl is
used. This technique is used for maintenance therapy, once acute severe pain is addressed.

Key to remember:

    •    Slow injection over 30-60 seconds as it can sting
    •    A fixed concentration of drug is used
    •    Do NOT flush between doses
    •    The elderly need longer intervals between doses because of delayed absorption.

NB. Hypovolaemic/hypotensive patients may have poor blood supply to the
subcutaneous tissues secondary to vasoconstriction. The subcut opioid may
therefore form a depot in the tissues that is released as the patient is
resuscitated/warmed. This can lead to delayed sedation following an administered
dose.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 18 of 70
5. Transdermal fentanyl (See page 14)

6. Use of oral opioids

Oral opioids are not for severe acute pain, or pain experienced in the acute
postoperative/postnatal period because of the unpredictability of pain in this period and
patients’ opioid requirements. Also patients’ GI tracts are often not functioning well, if at all, for
a variety of reasons so use of oral opioids is contraindicated.

However, once the acute postoperative/post-trauma phase is past and/or gastrointestinal
function has returned, the oral preparations may be useful. Long-acting or sustained release
preparations provide good background analgesia with the option for the quicker acting
preparations available for ‘break-through’ /incident pain if required.

Oral opioids also allow for a ‘step-down’ regime, where those patients on parenteral opioids
for longer than 7-10 days may require a weaning off opioid therapy.

Because of the first-pass effect and difficulty in predicting absorption, conversions
from parenteral to oral need to be carefully calculated. It is also important to remember
that the majority of patients are opioid naïve. What this means is that they are not
used to or tolerant to opioids. Prescribers should therefore be vigilant when choosing
a dose and regularly review it for effect/side effect.

As a guide, an adult patient receiving PCA morphine of 50mg in 24 hours, would
probably need around 2.5 to 3 times this dose given orally. This converted dose
may be given as a combination controlled release (CR) and shorter-acting
opioid. Using the example above:

50mg IV morphine = 150mg oral morphine in 24 hours. One third of this dose
can be prescribed as a controlled release preparation (eg 30mg LA-morph BD)
with the remainder given as rescue (eg 10 – 20mg sevredol prn- 2hourly).

The dosing intervals for oral preparation will depend on the form used. Controlled
release morphine can be given as a daily, twice daily or three times daily drug,
whereas the shorter acting elixir or tablets can be given up to 2 hourly. As a general
rule, for adult patients in Waikato Hospital, LA-morph is the preferred CR opioid,
unless patients are admitted already taking and used to M-eslon.

Oral opioids and nasogastric tube/PEG tube administration

As a rule of thumb, short-acting preparations can be given via NGT/PEG and
preferably either as a solution (eg morphine elixir) or capsules opened and sprinklets
flushed through with H2O. Never crush a controlled release tablet as this changes
its pharmacokinetics, which could give the patient an overdose of opioid.
If unsure, seek advice from a pharmacist or the IPS.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 19 of 70
         3.1 IV Administration of Opioids for Acute Pain Control in Adults

When to use this protocol                                            Unacceptable pain on routine
                                                                          analgesic regime
This protocol is intended to guide the rapid and
safe titration of strong opioids IV to treat acute
opioid responsive pain.
                                                                               Yes
It is designed for rescue analgesia for a patient
whose routine prescribed analgesia is either
ineffective or poorly tolerated.                                                                         Call ward medical staff, or
                                                                                                   No    APS if patient is already an
                                                                          Is IV opioid charted?
It may also be used for analgesia during                                                                        APS patient.
painful procedures.

                                                                               Yes


                                                                    Prepare syringe with prescribed
                                                                    opioid. Check that naloxone is
Standard opioid solutions for use within                                 charted and available
this protocol.
                                                                               Yes
All solutions involve dilution of the opioid to 10
ml with 0.9% saline in a 10 ml syringe.

Morphine 10 mg diluted up to 10 ml with 0.9%                                                                            Patient needs
normal saline.                                                                                                         medical review
Final Conc =1mg/ml                                                                                                    before any further
                                                                  Easily rousable to voice HR and BP         No to     opioid is given.
Fentanyl 200 mcg diluted up to 10 ml with                                 within patient's norm               any     Call ward medical
0.9% normal saline.                                               Resp rate 10/min or more. O2 Sats
                                                                                                                       staff, or APS if
Final conc = 20 mcg/ml                                                      95% or greater?
                                                                                                                      patient is already
                                                                                                                       an APS patient.
Tramadol 100mg diluted up to 10 ml with
0.9% normal saline.
Final conc = 10 mg/ml
                                                                             Yes to
Pethihdine 100mg diluted up to 10 ml with                                     all
0.9% normal saline.
Final conc = 10 mg/ml                                                                                                No      Give 0.5
                                                                                                    Age < 80 yrs &
                                                                        Age < 65 yrs?                                           ml
                                                                                                     wgt > 50 kg?
Do not use any other solution with this protocol
unless it has been approved by the APS.
Pethidine is seldom indicated.                                                                      Yes to
                                                                           Yes
                                                                                                     both


                                                                       Pain severe or                   Give 1
                                                                                              No         ml
Notes of caution:                                                   unacceptable despite
                                                                       2 prior doses?
Oxygen, Naloxone and suction must be rapidly
available to the patient and oximetry must be                            Yes
used.
                                                                           Give 2
                                                                             ml
Do not start this protocol unless you can stay
in close attendance with the patient while the
opioid is being given and for 15 min after.                                Wait 3
                                                                          min then
If the patient has renal impairment the fentanyl                          reassess
or tramadol are the preferred drugs. If they                                pain
are markedly at risk for respiratory depression                                                         Patient's pain is now under
then tramadol is the preferred drug option.                                                             control. Continue basic obs.
                                                                         Is pain still        No        Q5min for a further 15 min.
The peak effect of IV morphine occurs up to 15                         unacceptable?                    Return to the routine prescribed
mins after the dose is given.                                                                           analgesia and consider whether
                                                                         Yes                            it is adequate.
This protocol is not intended to be used for
routine analgesia or the management of
chronic pain.                                                          Have less than                   Patient's pain is unacceptable
                                                                     5 doses been given            No
                                                                                                        despite rescue opioid. Further
If the patient's pain seems much worse than                              within the                     assessment is needed urgently.
you would expect then seek medical advice.                              last 30 min.                    Call ward medical staff, or APS
                                                                                                        if patient is already an APS
                                                                       Yes                              patient.


         Note: Pethidine should not be prescribed as the opioid for PCAs, because of
         the toxicity problems associated with extended use. Consider using Fentanyl
         in this situation.

         Fentanyl is the recommended opioid for patients with severe acute or chronic
         renal failure.



                                                                                         st
         WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010            Page 20 of 70
3.2 Patient-Controlled Analgesia

For post-operative/post-trauma analgesia, the Anaesthetist prescribes on the patient’s
PCA prescription form the dose, lockout interval, and maximum hourly dose rates. The
patient self-administers the opioid within these prescribed limits.

Additional bolus doses of the prescribed opioid may be given by an RN certificated for
PCA, if the patient cannot achieve adequate pain relief with self-administration. These
additional, RN-administered boluses may only be given if prescribed and must be
given according to the instructions on the Pain Service Prescription form for patient
controlled analgesia.

Patient selection.

Prior to commencement/prescription of PCA.
        The patient should:
           • Be mentally alert.
           • Be able to comply with instructions.
           • Want to participate in his or her own pain management.
           • Be able to operate the PCA pump.
        Preoperative instructions by the Anaesthetist should include:
           • The rationale for PCA.
           • Use of machine: PCA information for patients (pamphlet).
           • Explanation of safety features.
           • Explanation of monitoring: sedation and pain scores, etc.
           • The role of the IPS in the management the PCA.
           • The likely duration of PCA therapy.


Management of patients with PCA at Waikato Hospital

 Opioid             Comments                                      Preparation
 Morphine *         First choice in most patients.               • 1 mg/mL solution: available in pre-
                    Less suitable in patients with                filled 100 mL polybags.
                    significant     PONV      (post-             • Higher concentrations can be ordered
                    operative       nausea      and               but require to be prepared by ward
                    vomiting),            “morphine               nursing staff.
                    sensitivity”, and in those with
                    renal impairment/failure
 Fentanyl           First choice in patients with                • 10 mcg/mL solution: available in pre-
                    renal impairment (lacks active                filled 100 mL polybags.
                    metabolites)      and    useful              • Higher concentrations may be ordered
                    alternative opioid.                           for specific patients but require to be
                                                                  prepared by ward nursing staff.

 Tramadol *         May be useful in patients:                   • 10 mg/mL: standard solution in
                    - Where it is important to avoid              100 mL bag
                    sedation (e.g. elderly patients              • Required to be prepared by ward
                    or those with obstructive sleep               nursing staff.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 21 of 70
                    apnoea).                 • Usefulness restricted by limits placed
                                              on maximum dose that can be used.
                    - Or to minimise opioid-related
                    adverse effects on bowel  Product information sheet suggests
                    function.                 maximum 600 mg daily.
                                              Note: There are a number of
                                              contraindications & precautions listed
                                              in the Product Information sheet. This
                                              includes other drugs that affect re-
                                              uptake of serotonin (e.g. SSRIs),
                                              MAOIs, and other drugs or diseases
                                              that may lower the patient’s seizure
                                              threshold.
                                              • Recommend stopping tramadol and
                                              contacting the IPS if signs suggestive
                                              of serotonin toxicity noted (e.g.
                                              agitation/restlessness,            fever,
                                              confusion, tremor, hyperreflexia).
    Oxycodone Less familiar    but useful • Required to be prepared by ward
              alternative to morphine and nursing staff.
              may cause less sedation        • 100mg/100mL        with     a       final
              Does      not  have     active concentration of 1mg/mL
              metabolites                    • Dosing is the same as for morphine
                                              PCA

* Note: These opioids have active metabolites that depend on the kidney for
excretion, and therefore should be used with caution in patients with renal impairment.

Prescribing doses for PCA

There are a number of standardised drug protocols pre-programmed into the PCA
pump library (see appendix 3). In most instances these will be adequate for the
majority of patients prescribed PCA. For opioid tolerant patients, eg those on a
background of opioid already for pain relief or those who are on the “methadone
programme”, customised doses will be required. If unsure, seek advice from a
member of the Pain Service.

•     In patients > or = 70 yrs consider reducing doses by 50%
•     PCA is essentially a maintenance therapy, therefore a patient’s pain should be
      controlled before PCA is started.
•     It is best to titrate the opioid analgesia before starting the PCA using the ‘IV Opioid
      Titration’ protocol (see pg 20).
•     The clinician activated dose refers to nurse-administered bolus doses of the opioid.
      This bolus is used when the patient’s pain is no longer controlled. It is best to use
      this bolus dose to titrate the opioid analgesia using the algorithms (refer ‘IV Opioid
      Titration’ protocol).



Concurrent background (continuous/basal) opioid infusions



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 22 of 70
There is no evidence to show that the routine addition of a background infusion to IV
PCA improves pain relief or sleep patterns. It does not always reduce the number of
demands made by the patient but does increase the total amount of opioid delivered.
Large audits of adult patients have shown that background infusions significantly
increase the risk of respiratory depression (ANZCA, 2010). Therefore routine use of a
background infusion is not recommended.

However, a background infusion may be of benefit to some patients: those who are
opioid-tolerant on admission to hospital, those requiring very high doses of opioid, and
also patients who wake in severe pain at night. In these situations the opioid
requirement of the patient is likely to be known and the infusion rate calculated
accordingly. Alternatively, if the patient has a functioning GI tract, background oral
opioid can be provided, especially for those patients who wake at night with severe
pain. This is in fact easier and safer than reprogramming the PCA pump for such
delivery.

Calculation of background infusion rate:

         (a) Opioid-naïve patients:
         Infusion rate ~ 30 - 50% or less of patient’s current opioid requirements. The
         daily opioid requirement should be recalculated daily.


  Example:
  A patient has used 100 mg morphine in the               previous 24 hours and is complaining
  of waking in severe pain.
                        100 mg in 24 hours                =         4 mg/hr (approx)
                        30-50% of 4 mg/hr                 =         1.5 - 2 mg/hr
         Therefore background infusion                    =         2 mg/hr



         (b) Opioid-tolerant on admission:
         If the patient is unable to take oral medication, consider a background infusion
         equal to 50% of his or her normal maintenance opioid requirements.

Transitional oral analgesia after PCA

PCA can be discontinued when the patient is able to tolerate oral fluids, unless opioid
requirements are high (eg undergoing repeated operations) or the patient is at risk of
significant incident pain (e.g. fractured ribs, underwater sealed drain (UWSD or ICD)
or dressing changes). Any of the oral opioids suitable for the management of acute
pain may be used following PCA.

The dose of oral opioid prescribed can be based on the amount of opioid used in the
24 hours prior to ceasing PCA and the relative equianalgesic doses of opioids (see
Appendix II for opioid conversion table).

There is little benefit in charting two different low-dose opioids — if one opioid is
inadequate then the dose should be increased.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 23 of 70
Suggestions for transitional oral analgesia after PCA

PCA requirements in last 24 hours Suggested analgesic agent.
(morphine)
< 10mg                            Paracetamol,
< 20mg                            Paracetamol plus Tramadol or
                                  Codeine Phosphate +/- NSAIDs
20–50mg                           Paracetamol plus Oxycodone or
                                  Tramadol +/- NSAIDs
> 50mg                            Paracetamol                   plus
                                  Oxycodone/sevredol +/- NSAIDs

Calculation of Oral Oxycodone dose

If oral oxycodone is prescribed to follow IV morphine PCA, it is a good idea to convert
the daily IV morphine dose to its equivalent oral morphine dose. For example: 60mg
IV morphine roughly equates to 180mg oral morphine.

Oral oxycodone is twice as potent as oral morphine, largely because of its better
bioavailability, so once the oral morphine dose is calculated, halve it for the oral
oxycodone dose. In the example above, this means that rather than 180mg oral
morphine, the oral oxycodone dose would equate to only 90mg.

When prescribing the oxycodone, it may be appropriate and beneficial to prescribe a
small dose of long acting preparation (Oxycontin) (using the formula which
recommends ⅓ of the daily total). Using the oxycodone example above 30mg could
be given in divided doses 12 hourly with a small dose of oxynorm (the immediate
release form of oxycodone) e.g. Oxynorm 5 mg q2-3 hourly prn for ”rescue” analgesia.
If unsure, please consult with a member of the Inpatient Pain Service

PCA plus Oral Oxycodone:

If PCA requirements are higher than 100 mg morphine (or equivalent) in the last 24
hours, oxycontin can be used to substitute for approximately half of this requirement
and the PCA dose can then also be halved. PCA can be further reduced or ceased the
next day with appropriate increases made as needed to oxycodone doses.

General Management of PCA Therapy

1. OXYGEN
By mask or nasal cannula should be given initially during PCA until oxygen saturations
on room air have been checked as satisfactory by pulse oximetry and maintained at
the level prescribed on the general treatment orders by the anaesthetist.

2. NALOXONE (NARCAN)
Naloxone 0.4 mg ampoules must be available in the ward at all times.

3. ADDITIONAL OPIOIDS/SEDATIVES




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 24 of 70
Unless prescribed by IPS/Anaesthetist, the concurrent use of additional shortacting
opioids, eg sevredol with PCA is not acceptable, nor does it offer any additional
benefit to the patient’s analgesia. Some anaesthetists may permit the use of tramadol
in association with PCA because of its pharmacodynamics that may provide additional
pain relief for individual patients, and will indicate this on the patient’s medication
chart.

Any other medicine that has sedative properties, and this includes antihistamines,
sleeping tablets, anxiolytics, anticonvulsants, antiemetics, antidepressants may be
given if ordered but close observation and documentation of sedation is essential.

4. ROUTINE PCA OBSERVATIONS

Sedation Score, Respiratory Rate/Depth, Blood Pressure, Pulse, Pain (at rest and with
movement/activity) and Oxygen saturations
    q ¼-hourly for 1 hour
    q 1-hourly for 4 hours
q 2-hourly sedation and respiratory rate if stable, with q 4-hourly B/P, pulse, oxygen
saturations and pain score

Sedation Score


Sedation is the most reliable indicator of pending respiratory depression.

    0    =        none
    1    =        mild – occasionally drowsy, easily roused
    2    =        moderate – frequently drowsy, easily roused
    3    =        severe – somnolent, difficult to rouse
    S    =        sleeping normally, easily roused

Note: if patient asleep please note ‘S’ on the chart if all observations are normal

If there is a trend of increasing sedation, the appropriate troubleshooting guidelines
(on PCA form) should be consulted and the IPS/anaesthetist should be informed.


    Pain Intensity
The best way to assess pain in a patient is by using the verbal or visual analogue
scale, which should be done at rest and also movement e.g. coughing. Omit pain
score if patient is asleep. The patient’s pain score should be equal to or less than 4/10
at rest, and pain should not limit the patient’s ability to participate in their activities of
daily living/recovery.


    Pain Scale



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 25 of 70
NO PAIN         0----1----2----3----4----5----6----7----8----9----10                          WORST
                                                                                              IMAGINABLE

5.       INADEQUATE ANALGESIA

•    Consider another cause, e.g. the development of a post-surgical or post-injury
     complication.
•    If the patient is administering ≤2 doses/hr (average), re-educate the patient and
     encourage more frequent use of the demand button.
•    If the patient is requesting ≥3 doses/hr (average), the dose size may need to be
     increased.
•    The patient cannot use the hand-held demand button. Consider infusion +/- nurse-
     administered boluses (refer opioid protocol)
•    The pain may be poorly responsive to opioids (e.g. neuropathic pain).

6.       NURSE-ADMINISTERED (CA) BOLUS DOSE

If patient’s pain is severe, nurse administered bolus doses may be required to achieve
control. Please follow the instructions on the front of the Pain Service patient
controlled analgesia prescription form.

7.       SIDE EFFECTS

(a) Sedation/respiratory depression (see Appendix III for Troubleshooting Guidelines
Flowchart)

(b) Nausea / Vomiting

     Administer antiemetics as per guidelines (see Appendix V)
     Consider addition of droperidol to PCA — 2.5-5 mg droperidol added to 100ml
     polybag of morphine. Nausea and vomiting may be significantly reduced but at the
     cost of over sedation.
     Consider dexamethasone 4-8mg IV once only.
     Consider other possible causes of nausea/vomiting.
     Consider changing to another opioid.

(c) Pruritus

     Check that pruritus is likely to be opioid related (e.g. if on face and trunk ensure it
     is not an itchy rash with another aetiology)
•    Change to fentanyl if pruritus is thought to be due to morphine and is annoying the
     patient.
•    Consider cyclizine 12.5 mg IV. NB: pruritus is not due to histamine release but an
     action on opioid receptors.
•    Low-dose naloxone may relieve pruritus but it may reverse analgesia if
     administered repeatedly, therefore consider a single 100 mcg dose
     subcutaneously or 40 mcg IV q. 30 mins up to a maximum of 3 doses.
•    Owing to the sedative nature of promethazine (phenergan) it is generally not
     recommended for the management of itch. Loratidine is a non-sedating alternative.
     10mg once daily with/without food.

                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010    Page 26 of 70
(d) Constipation:

      Nursing and medical staff equally are responsible for ensuring that patients’ bowel
      habits are not neglected during their hospital admission. Where possible avoid
      constipation by maintaining adequate hydration/nutrition and exercise. When
      prescribing opioids, routinely chart laxatives.

      The following foods are effective laxatives – kiwifruit, prunes, kina.
      Other pharmacologic remedies include lactulose, coloxyl and senna, laxsol,
      movicol.

(e) Urinary retention

      Catheterise

(f) Confusion

      Possibly not PCA opioid-related, however PCA should be reviewed. All other
      potential causes need to be excluded. Look for other possible causes (e.g.
      hypoxia, sepsis, and alcohol or benzodiazepine withdrawal).

8.        AMBULATION AND SHOWERING

      Opioids do not cause muscle weakness. Assess patient for postural hypotension
      by first sitting him or her in a chair before commencing assisted ambulation.
      Remain with the patient when showering.

9.        ADMINISTRATION SETS and POLYBAGS

      Administration sets: changed every 72 hrs and labelled with date
      Note: Check that it is the correct infusion tubing with a one-way valve.
      Polybags: in the majority of patients, PCA will be discontinued within 48 hours,
      but for those patients still on PCA at 48hrs, the polybag MUST be changed. The
      new polybag must be labelled with the patient’s identification, as well as time and
      date.

10.       NURSING COMPETENCY

      Registered and enrolled nurses may care for patients using a PCA only after
      instruction on the use of the PCA pump and attending the pain management
      education.

11.   PCA KEY — Is kept with the Controlled Drug Keys
4.0 Regional Analgesic Methods

Continuous Epidural Infusion Analgesia (CEIA)

      •   Pain relief by continuous infusion of agents (i.e. local anaesthetics and/or
          opioids) into the epidural space via an indwelling epidural catheter.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 27 of 70
    •    Used for management of acute pain following some types of surgery, trauma,
         and labour analgesia.
    •    Anaesthetist places epidural space catheter at various levels for a wide variety
         of operations.
    •    Can provide better pain relief than parenteral opioid administration when
         working well
    •    Epidural opioids alone seem to be of limited benefit.
    •    Combination of low-concentration local anaesthetic plus opioid provide
         consistently superior pain relief compared with either alone.

Patient-Controlled Epidural Analgesia (PCEA)

    •    Pain relief by continuous infusion of local anaesthetics and/or opioids into the
         epidural space via an indwelling epidural catheter with a patient-controlled
         demand device that allows additional boluses upon patient request.
    •    Used instead of CEIA for management of acute pain following some types of
         surgery, trauma, and labour analgesia.

Management of patients with epidural infusions in Waikato Hospital

Set-up for Epidural Infusion Analgesia:
   • Administer via Epidural pump. These pumps have a yellow “epidural” label
      attached and are used for epidural infusions only.
   • Use only specially designed YELLOW epidural tubing, with no injection ports.
   • Label this tubing with “Epidural only” labels.
   • These precautions help avoid accidental injection of IV medication into the
      epidural, and IV injection/infusion of local anaesthetics which may lead to
      cardiac arrest.

Epidural Analgesic Solution:

 Solution                              Comments              Preparation
 Ropivacaine/Fentanyl                  Pre packaged polybags Ropivacaine 0.2%
                                       available        from Fentanyl 2 mcg/mL
                                       Pharmacy

Usual infusion rate range:
       Younger patients (16–35)                                          8–15 mL/hr
       Older patients (e.g. over 75 yrs)                                 4–8 mL/hr

Notes:
   • Doses can vary according to factors such as catheter site and patient size.
   • High thoracic epidural infusions may require lower infusion rates.
   • Epidural will rarely cover both the thoracic wound and chest drains. PCA may
       be required but should only be used in consultation with the IPS.
   • Lower infusion rates are used with higher concentrations of local anaesthetic.
   • Do not change infusion rate outside prescribed range without first contacting
       IPS.

General Management:


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 28 of 70
1. OXYGEN

By mask or nasal cannula should be given initially during epidural infusion and only
stopped after oxygen saturations on room air have been checked by pulse oximetry.
Ward protocols may vary from this and should be followed. Sedation is more accurate
than respiratory rate or Sp02 in assessing respiratory depression. Thus the sedation
scores and respiratory rate must be monitored and recorded.

2. IV CANNULA

IV access must be maintained for 6 hours after ceasing the epidural infusion.

3. NALOXONE (NARCAN)

Naloxone 0.4mg ampoules must be available in the ward at all times.

4. ADDITIONAL OPIOIDS/SEDATIVES

Do NOT give additional opioids/sedatives by any route unless discussed with IPS or
prescribed by an Anaesthetist.

5. PHYSIOLOGICAL PARAMETERS

Aside from standardised and pre-printed acceptable sedation, respiratory rate, pulse
and pain score parameters, the anaesthetist will document acceptable parameters for
systolic blood pressure and oxygen saturations for individual patients on the epidural
prescription form.
If these parameters are exceeded, contact the APS/Anaesthetist immediately.

6. CHANGING OF INFUSION RATE

The infusion rate may be changed in 2 mL increments within the prescribed range to
improve the block.
Do NOT change the rate outside the prescribed range without first contacting IPS.
Provided all observations are stable, a slightly higher sensory block is better than a
block which only just covers the painful area.

7. BOLUS DOSES

Only to be given by RNs or Midwives who hold epidural certification, IPS staff or an
Anaesthetist and must be recorded by them on the Epidural Prescription Form and
Observations Chart.
Observations as per clinical observations.

8. CLINICAL OBSERVATIONS

Routine post-operative blood pressure, pulse, sedation, respiratory rate, pain and
oxygen saturation.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 29 of 70
         q ½-hourly 4 hrs
         q 1-hourly 4 hrs
         q 2-hourly 12 hrs, if stable q 4-hourly
Urine output should be measured and should be assessed within the clinical situation.


If an epidural bolus is given:
•   Blood pressure, pulse — every 5 minutes for 20 minutes.
•   Blood pressure, pulse, respiratory rate, sedation and pain scores — at 20
    minutes.
The IPS or the Anaesthetist concerned must review patients who are unable to move
their legs and feet. It is often seen immediately post-operatively if high concentrations
of local anaesthetics have been used with lumbar epidurals.


9. MONITORING FOR POTENTIAL NEUROLOGICAL COMPLICATIONS

Each patient should be checked daily by IPS for:
      • any inflammation / induration at the epidural catheter insertion site
          Note: if present, remove catheter at appropriate time relative to any
          anticoagulants (see appendix VI For anticoagulants and epidural
          anaesthesia/paravertebral analgesia protocol)
      • back pain or radicular pain
      • pain or tenderness at insertion site
      • pyrexia
      • any neurological deficit (sensory, motor, bladder/bowel)

Motor and sensory function must also be monitored 4hourly. Close observation and
documentation of pressure areas is also expected at least once per shift

For thoracic epidurals: contact IPS immediately if there is any neurological
abnormality in upper or lower limbs.
For lumbar epidurals: sensory and motor block in lower limbs is common. If it
progresses, contact IPS or an Anaesthetist immediately.

10. MANAGEMENT ISSUES:

         a. Inadequate Analgesia:
               • contact IPS to assess patient
               • regular simple analgesics (e.g. paracetamol, NSAIDs if appropriate)
               • Additional opioids should not be prescribed without consultation with
                   the IPS
            Note: shoulder tip pain may require small doses of IV opioids.

         b. Respiratory            Depression:           (See      Appendix          III   -       Troubleshooting
            Guidelines)


                 APNOEA
                                    o    BASIC LIFE SUPPORT
                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010          Page 30 of 70
                                    o    Dial 777, activate cardiac arrest

                                    o    Administer naloxone 0.4mg (1 ampoule) IV
         c. Hypotension

                  •    Look for hypovolaemia and other causes of hypotension, eg
                       bleeding.
                  •    Check sensory level
                  •    Inform IPS/Duty Anaesthetist
                  •    Call H/S to see and assess the patient immediately

         d. Epidural haematoma/abscess

              Signs and symptoms may include:
                 • Back pain
                 • Radicular pain
                 • Neurological deficits (motor, sensory, bowel, bladder)
              Note: a patient with an epidural abscess may not be pyrexial.

              For possible epidural abscess/haematoma, IPS/Anaesthetic staff must:
                 • Immediately — perform history and examination
                 • Immediately contact surgical team
                 • Arrange an Urgent MRI scan within 6 hours of onset of symptoms to
                    be of benefit.
                 • Obtain Urgent Neurosurgical assessment
                 • Urgent surgical decompression is required if evidence of nerve or
                    spinal cord compression present and no contraindications to surgery.
                 • Routine culture of epidural catheter tips is not required because
                    contamination on removal is common and results are therefore
                    unreliable.

         e. Nerve or spinal cord injury

                  •    Nerve injury is more commonly seen owing to causes unrelated to
                       epidural and spinal analgesic/anaesthetic — such as after trauma
                       (e.g. # pelvis) and surgery.
                  •    History and examination will help to determine site and extent of
                       injury as well as onset of signs and symptoms.
                  •    Liaise with surgical team to discuss findings.
                  •    A formal neurological assessment may be warranted.

         f. Post-Dural Puncture Headache (PDPH):

                  •    History and examination to assess if signs and symptoms are
                       suggestive of post-dural puncture headache:


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 31 of 70
                          a. Postural (eg worse on sitting up, easing when patient lies
                              down), frontal, & /or occipital headache
                          b. nausea &/or vomiting
                          c. exclude other serious causes of headache.
                  •    Analgesic (simple and/or opioid)
                  •    Hydrate (oral or IV)
                  •    Reassess
                  •    Positioned prone if practical
                  •    Blood patch is an option for persistent and disabling headache.
                       Note: Patient must have a normal temperature and WCC (white cell
                       count and coagulation screen). Informed consent must be obtained.


         g. Localised infection at the catheter insertion site

                  •    Culture only if frank pus seen
                  •    Daily IPS review to check insertion site and for any neurological
                       changes, until infection is resolved
                  •    Consider referral for surgical intervention if infection failing to resolve

         h. Urinary retention

                  •    Contact house surgeon
                  •    Should catheterise.

         i. Pruritus

                  •    Check that pruritus is likely related to epidural
                  •    Consider naloxone 100 mcg S/C
                         Or 40 mcg IV Q 30 min, max 3 doses.

11. AMBULATION AND SHOWERING

Thoracic epidural infusion does not exclude patient mobilisation or showering. With
low-dose infusion regimes most patients may be mobilised as usual. Assess patient
for postural hypotension by first sitting him or her on the edge of the bed, then in chair
before commencing assisted ambulation. Remain with patient at all times while
ambulatory or showering.

Lumbar epidural infusion does usually exclude patient mobilisation.
Criteria for safe weight bearing with lumbar epidural:
   • Ability to maintain a straight leg raise, one at a time, in both limbs, in bed.
   • Ability to sit and then stand, with support, without syncope, dizziness or
       postural hypotension.
   • An ability to stand unsupported.
   • Patient confident that he or she can walk.
   • Patients must be assisted and escorted on each occasion they mobilise.
   • Avoid darkened areas and uneven surfaces. Proprioception (position sense) is
       often lost so there is extra reliance on other sensory input to maintain balance.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 32 of 70
These are suggested safe criteria. If there are any worries err on the side of caution. If
there are problems please check with IPS or Duty Anaesthetist.

12. PREVENTION OF PRESSURE SORES AND DEEP VEIN THROMBOSIS

Most patients should retain motor function with current low dose infusion regimes, i.e.
should be able to move legs and feet.
      • Check patient can move legs and feet.
      • Remind patients to move legs and feet regularly.
      • If the patient cannot move legs and feet contact IPS.
      • Check on pressure areas (heels and sacrum) regularly to avoid pressure
          sores.

13. NURSING COMPETENCY

    Registered nurses/midwives with epidural certification may care for patients on
    epidural infusions.

14. POLYBAG CHANGES

         •    Polybag changes should be performed by 2 nurses, one of whom is an RN.
         •    Remember to reconfirm infusion pump settings against Medication Chart
              prior to recommencing infusion.

15. ADMINISTRATION SETS

         •    Only to be changed by certificated nursing staff or IPS staff if required.

16. EPIDURAL CATHETER CARE

         •    Occlusive dressings should keep catheter dry and immobile.
         •    AND allow inspection of insertion site.
         •    A slight ooze of tissue fluid is common.
         •    Epidural insertion site will be inspected daily on IPS ward round
         •    Epidural insertion site should ALSO be assessed by ward nursing staff on
              each shift, and the condition of the site documented in the patient’s clinical
              record.
         •    Ward nursing staff MUST contact IPS if concerned about the site (redness
              or induration around insertion site, fluid leak, pus, dressing becoming
              detached or loose, etc.) or the patient’s temperature is ≥ 38.
         •    If epidural catheter becomes detached from the filter, cover with a sterile
              dressing and contact IPS/anaesthetist immediately, as the catheter may
              need to be removed.

17. INFUSION PUMPS

         •    Keep on mains power at all times except for ambulation.
         •    Clean and return to the Post Anaesthetic Care Unit (PACU) when
              discontinued on patient for which it was prescribed.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 33 of 70
         •    Do not discontinue infusions without notifying IPS and pumps should not be
              used for other purposes without IPS approval.

18. ADDITIONAL ANALGESIA

Commence additional analgesics (preferably non-opioid e.g. Paracetamol, NSAIDs)
as soon as possible, to improve overall analgesia and facilitate successful
discontinuation of epidural when appropriate.

19. DISCONTINUATION OF EPIDURAL ANALGESIA

         •    Before discontinuing an epidural infusion commence an effective alternative
              analgesic regime, e.g. Oral Oxycodone (good choice post-thoracotomy).
              Note: do not send patients home on recently started oxycodone without
              discussing with an IPS consultant or Anaesthetist.
         •    Epidural infusions are not “weaned”. The infusion should be stopped.
         •    After epidural infusion is discontinued, leave epidural catheter in place until
              epidural block has worn off completely (usually 2 hours) and don’t remove it
              within the stated delay following administration of anticoagulants (see
              epidural blockade protocol). Discuss with IPS/anaesthetist.
         •    If pain remains well controlled: Remove epidural catheter as per protocol
              (see epidural –removal of catheter procedure on the Intranet).
         •    If severe pain returns: May need to restart epidural infusion at previous rate.
         •    Infusion restart may need to be combined with a bolus dose.
         •    Significant alterations to epidural management should be discussed and/or
              made known to IPS or duty Anaesthetist. IPS cannot accept further
              responsibility without such consultation
         •    If patient is not tolerating oral fluids or the epidural has been removed earlier
              than expected, PCA needs to be provided as alternative analgesia.

20. REMOVAL OF EPIDURAL CATHETER

         •    To reduce risk of epidural haematoma, removal time must be optimised
              against other treatments which may lead to coagulation system alterations.
         •    Catheter removal timing must be as prescribed by IPS, in accordance with :
                 ‘Anticoagulation and Epidural Anaesthetia’ guidelines (see appendix…)
         •    Epidural catheters must only be removed by RN with current ‘Nurse
              Epidural Certificate’, or Anaesthetist.
         •    Check removed catheters to ensure tip is still attached.
         •    Document both condition of site and removal of catheter in patient’s clinical
              record




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 34 of 70
4.1 Interpleural and Paravertebral Analgesia

Interpleural infusion analgesia

Used for relief of chest and abdominal pain by infusing local anaesthetic between the
visceral and parietal pleura via a fine catheter.

Local anaesthetic solution diffuses through parietal pleura and innermost intercostals
muscles to block the intercostal nerves and sympathetic chain.

Interpleural infusion analgesia is commonly used post-operatively in conjunction with
intravenous PCA or opioid infusions as supplementary analgesia.

If combined with PCA, also observe protocols for managing PCA usage.

Paraverterbral analgesia

A fine catheter sits longitudinally in the potential space between the parietal pleura
and ribs posteriorly, about 5 cm from the midline. Can be positioned either blindly by
the anaesthetist preopratively or under direct vision, to avoid vessel placement, at
thoracotomy. The aim is to place the catheter so that a pocket of local anaesthetic
(LA) overlies the relevant nerves. The block is used to provide unilateral analgesic
after thoracotomy (see paravertebral analgesia procedure guideline on the intranet).

Management of patients with Interpleural/Paravertebral catheters:

INFUSION REGIMES USED AT WAIKATO HOSPITAL

Ropivacaine 0.2% recommended rate range 5–10 mL/hr

PCA often prescribed simultaneously for patients with paravertebral analgesia

Do not change the infusion rate outside the prescribed range.
      • If inadequate analgesia contact IPS.

GENERAL MANAGEMENT

1. Oxygen
      • Mask or nasal cannula initially during interpleural infusion, and may need to
         be given continuously with paravertebral analgesia
      • Stop after pulse oximetry oxygen saturations on room air have been
         checked and fall within prescribed limits.
      • Ward protocols may vary from this and should be followed.
      • Sedation is more accurate than respiratory rate in assessing respiratory
         depression.

2. IV CANNULA

         •    Must be maintained for 6 hours after ceasing the local anaesthetic.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 35 of 70
3. BOLUS DOSES

         •    Only by RN with epidural certification, IPS staff, or an Anaesthetist.

4. CHANGING OF INFUSION RATE

         •    Within the prescribed range, to achieve a better block.
         •    Do NOT change rate outside prescribed range without first contacting IPS.

Provided that all observations are stable, a slightly higher sensory block is better than
a block, which only just covers the painful area.

5. OBERVATIONS

Observations should be taken in accordance with Waikato DHB protocol for
intravenous opioids if PCA used, otherwise follow epidural protocol for monitoring.

6. PAIN SCORE


The best way to assess pain in a patient is by using the verbal or visual analogue
scale, which should be done at rest and also movement e.g. coughing. Omit pain
score if patient is asleep. The patient’s pain score should be equal to or less than
3/10.


    PAIN SCALE

NO PAIN         0----1----2----3----4----5----6----7----8----9----10                          WORST
                                                                                              IMAGINABLE
7. SEDATION SCORE


Sedation is a significant indicator of pending respiratory depression.

   0 =         none
   1 =         mild — occasionally drowsy, easily roused
   2 =         moderate — frequently drowsy, easily roused
   3 =         severe — somnolent, difficult to rouse
   S =         sleeping normally, easy to rouse
Note: if patient asleep please note ‘S’ on the chart if all observations are normal.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010    Page 36 of 70
8. MANAGEMENT ISSUES

         •    Respiratory: shortness of breath or decreased oxygen saturation
         •    Consider pneumothorax and the need for an erect chest X-ray
         •    Administer oxygen
         •    Stop infusion
         •    Contact IPS and surgical/medical team

    Apnoea:
       • Basic Life Support = ABC
                  APNOEA
                                     o    BASIC LIFE SUPPORT

                                     o    Dial 777, activate cardiac arrest

                                     o    Administer naloxone 0.4mg (1 ampoule) IV


    Local anaesthetic toxicity:

    Symptoms of Local toxicity may include:
      • Ringing in the ears, numbness of the face, tingling in the hands/arms
      • Confusion
      • Unconsciousness
      • Convulsion
      • Cardiac Arrest

    Actions
       • Stop infusion
       • Basic Life Support – Dial 777 (if severe compromise or cardiac arrest)
       • Contact IPS and surgical/medical team

9. AMBULATION AND SHOWERING

         •    Interpleural or paravertebral infusion does NOT exclude patient mobilisation
              or showering.
         •    Most patients may be mobilised as usual.
         •    Assess patient for postural hypotension by first sitting him or her on the
              edge of the bed and then in a chair before commencing assisted
              ambulation.
         •    Remain with the patient at all times while ambulatory or showering.

10. NURSING COMPETENCY

         •    Registered nurses with epidural certification may care for patients on
              interpleural and paravertebral infusions.

11. ADMINISTRATION SETS
      • Will be changed as needed by APS staff.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 37 of 70
12. INTERPLEURAL/PARAVERTEBRAL CATHETER CARE

The occlusive dressings used should keep the catheter dry and immobile, but also
allow for inspection of the insertion site. A slight ooze of tissue fluid is common.

The interpleural/paravertebral insertion site will be inspected daily on IPS ward round
and should also be assessed by the ward nursing staff on each shift. Ward nursing
staff MUST contact IPS should they be concerned about the site (redness or
induration around the insertion site, fluid leak, pus, dressing becoming detached or
loose, etc.) or the patient’s temperature is ≥ 38.

13. INFUSION PUMPS

To be kept on mains power at all times except for ambulation etc. To be cleaned and
returned to the Post Anaesthetic Care Unit (PACU) as soon as discontinued on the
patient for which it was prescribed.

They are not to be discontinued without the prior discussion with IPS and should not
be used on the ward for other purposes without the approval of IPS.

14. DISCONTINUATION                      OF      INTERPLEURAL/PARAVERTEBRAL                        INFUSION
ANALGESIA

When an infusion has been discontinued, the infusion catheter should be left in place
until the block has worn off completely (usually 4 hours), and alternative analgesia
administered as appropriate. If the patient’s pain is then well controlled, the infusion
catheter may be removed. If severe pain returns the infusion may need to be restarted
at the previous rate. Restarting the infusion may need to be combined with a bolus
dose.

15. REMOVAL OF INTERPLEURAL/PARAVERTEBRAL CATHETERS

To be removed only after consultation with IPS, and following the recommendations of
removal of catheters for patients on anticoagulants (see epidural blockade protocol on
the intranet)

Removed catheters must be checked to ensure that the tip is still attached to the
catheter, and a note made to this effect in the patient notes. Occlusive plastic dressing
to be applied to insertion site for 24 hours and then removed.

If pus or extreme redness or induration is seen around the insertion site, a swab is to
be sent in a labelled specimen bottle to the microbiology laboratory for MC&S and IPS
informed.

16. ADDITIONAL ANALGESIA

Additional analgesics (preferably non-opioid e.g. Paracetamol, NSAIDs) should be
commenced as soon as possible to facilitate successful discontinuation of the
interpleural or paravertebral infusion when appropriate.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010    Page 38 of 70
4.2 Peri-neural Analgesia

Continuous regional and intermittent bolus analgesia is the relief of pain by instillation
of local anaesthetic around the nerves supplying the area that has been operated
upon — commonly an arm or leg. This includes local anaesthetic via brachial plexus,
fascia iliacus, femoral, trans-abdominal plane (TAP) block, and surgically placed peri-
neural catheters as with sciatic nerve/stump catheters following amputation. Wound
infusion catheters can be considered peri-nerve infusion catheters by the instillation of
local anaesthetic around nerves in the surgical wound.

Local anaesthetics such as Ropivacaine block impulse conduction in nerves. Sensory
and sympathetic and occasionally motor nerve blockade occurs. With the lower
concentrations of local anaesthetics used today motor blockade is seen less
commonly and patients may be mobilised even while the infusion is running. This form
of analgesia is commonly used in conjunction with PCA, as 100% analgesia is not
always achieved.

During a continuous regional infusion, boluses of the local anaesthetic infusion may
have to be given for break-through pain. Such boluses should only be used in
consultation with the IPS.

Patient-initiated boluses may be prescribed in addition to an infusion, but only with
prior consultation with the IPS. Such boluses are administered automatically via the
infusion pump on pressing the request button. Caution should be taken to ensure
potentially toxic amounts of local anaesthetic cannot be administered by over-
enthusiastic requests for boluses. Methods to avoid this include lengthy lockouts
between requested boluses and conservative rates for background infusions.

Pre-operative instruction to the patient should include:
• Instructions not to get out of bed unless instructed to do so by the nursing staff
• Explanation of the monitoring — pain scores and testing the level of sensory block

Set-up for peri-nerve local anaesthetic continuous regional infusions:

Administered either via an epidural volumetric pump or a syringe driver. Pump and
tubing to be clearly labelled with a yellow sticker “Local Anaesthetic” to avoid
accidental injection of IV medication. Use only the specially designed YELLOW micro
set epidural only tubing, or fine bore administration with no side ports.

Set-up for peri-nerve local anaesthetic intermittent bolus technique:

Bolus doses may be administered by direct injection into the wound catheter which is
labelled with a yellow sticker “local anaesthetic”, or by syringe driver/volumetric pump-
delivered bolus.

Note: the IV injection or infusion of local anaesthetics may lead to cardiac arrest.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 39 of 70
GENERAL MANAGEMENT

1. IV CANNULA

       IV access must be maintained during and for 6 hours after ceasing the regional
       (LA) infusion.

2. ADDITIONAL BOLUS DOSES WHILST ON INFUSION

       May be given as instructed by the anaesthetist and must be recorded on the
       Medication Chart.
       May only be given by an anaesthetist, medical staff member, or RN.

3. INTERMITTENT BOLUS DOSING WITHOUT INFUSION

       May only be given by an anaesthetist, medical staff member, or RN medicine
       management certification.
       Particular attention and care must be taken to avoid the accidental IV injection
       of local anaesthetics, therefore before injecting the local anaesthetic, the
       syringe should be aspirated to check for blood indicating IV placement of
       the catheter tip.
       Any wound catheter injection of local anaesthetic should be performed in 5 mL
       aliquots of the prescribed dose over 5–10 mins to allow the early detection of
       inadvertent intravascular injection.

       Signs of inadvertent IV injection or LA toxicity may include:
            Ringing in the ears (tinnitus)
            Tingling around the mouth
            Numbness of face
            Unconsciousness
            Convulsion
            Cardiac arrest

5. CHANGING OF INFUSION RATE

       The infusion rate may be changed within the prescribed range to achieve a
       better block. Do NOT change the rate outside the prescribed range without first
       contacting the IPS.
       Provided all observations are stable, a slightly higher sensory block is better than
       a block which only just covers the painful area.

6. OBSERVATIONS

       Routine post-op observations: blood pressure, pulse respiratory rate and pain
       and sedation scores and volume infused.
       Omit pain score if patient sleeping normally. Record any side effects.
       Observations to be recorded 4-hrly if stable for the duration of the infusion and
       for a further 12 hours once infusion discontinued.
       For intermittent dosing via catheter: observations taken and recorded every 10
       minutes for 30 minutes post administration of dose.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 40 of 70
       Inform IPS staff of any side effects: insertion site leaking excessively or any other
       problems or symptoms you think may be related to the therapy.

7. PROBLEMS

Apnoea:                       Basic Life Support = ABC etc.
                              Dial 777

Toxic reaction:               Symptoms
                               Ringing in the ears, numbness of the mouth, face
                               Confusion
                               Unconsciousness
                               Convulsion
                               Cardiac arrest
                              Actions
                               Stop infusion
                               Basic life support
                               Dial 777 (if severe compromise or cardiac arrest)
                               Contact IPS

8. AMBULATION AND SHOWERING

       The presence of a peri-nerve infusion does not exclude patient mobilisation or
       showering. Most patients may be mobilised as usual with the present infusion
       regimes. Assess patient for postural hypotension by first having him or her sit on
       the edge of the bed and then in a chair before commencing assisted ambulation.
       Remain with the patient at all times while ambulatory or showering.

9. PREVENTION OF PRESSURE SORES AND DEEP VEIN THROMBOSIS

       Most patients should retain motor function with the current infusion regimes and
       should be able to move their legs and feet. Remind patients regularly to move
       legs and feet. Check on pressure areas (heels and sacrum) regularly to avoid
       pressure sores.

10. NURSING COMPETENCY

       Registered nurses may care for patients on peri-nerve infusions ONLY after
       instruction in peri-nerve infusion pumps and procedures.

11. REGIONAL (LA) INFUSION CATHETER CARE

       The occlusive dressings used should keep the catheter dry and immobile, but
       also allow for inspection of the insertion site. An ooze of tissue fluid and/or local
       anaesthetic is common and may on occasions be substantial.
       The catheter insertion site will be inspected daily on the IPS ward round and
       should also be assessed by the ward nursing staff on each shift.
       Ward nursing staff MUST contact the IPS should they be concerned about the
       site (redness or induration around the insertion site, fluid leak, pus, dressing
       becoming detached or loose, etc.).


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 41 of 70
12. INFUSION PUMPS

       To be kept on mains power at all times except for ambulation etc, and to be
       returned to the Post Anaesthetic Care Unit (PACU) as soon as discontinued on
       the patient for whom it was prescribed.
       Infusion pumps should not be discontinued without the approval of the IPS and
       should not be used on the ward for other purposes without the approval of the
       IPS.

13. ADDITIONAL ANALGESIA

       Additional analgesics (preferably non-opioids, e.g. Paracetamol, NSAIDs) should
       be commenced as soon as possible to facilitate successful discontinuation of the
       peri-nerve infusion when appropriate.

14. DISCONTINUATION OF PERI-NERVE INFUSION ANALGESIA

       Do not discontinue regional (LA) infusion analgesia without having first
       prescribed and instituted an adequate and effective alternative analgesic regime.
       When an infusion has been discontinued the infusion catheter should be left in
       place until the block has worn off completely (usually 4 hours). If the patient’s
       pain is then well controlled the infusion catheter may be removed. If severe pain
       returns the infusion may need to be restarted at the previous rate. Restarting the
       infusion may need to be combined with a bolus dose.

15. REMOVAL OF REGIONAL (LA) CATHETERS

       To be removed only after consultation with the IPS. Removed catheters must be
       checked to ensure that the rounded tip is still attached to the catheter, and a note
       made to this effect in the patient notes.
       Occlusive plastic dressing to be applied to insertion site for 24 hours and then
       removed.
       If pus or extreme redness or induration is seen around the insertion site a swab
       must be sent in a labelled specimen bottle to the microbiology laboratory for M.C.
       & S. The IPS should be informed




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 42 of 70
5.0 Inhalational Analgesia

5.1 Nitrous Oxide (Entonox)

Nitrous oxide (N2O) was an early anaesthetic agent with potent analgesic properties.
It causes minimal respiratory and cardiovascular depression, and is widely used in the
management of labour pain and for painful procedures such as       burns     dressing
changes and venous cannulation.

Its use is contraindicated in patients with pneumothorax, bowel obstruction, air
embolism and severe bone marrow depression or similar haematological disorders
as well as in people who have altered level of consciousness, head injury,
maxillofacial injuries, intoxication with alcohol or other drugs (see Waikato Hospital’s
Entonox Administration guidelines on the intranet)

Onset of action is quick – following 20 seconds or five deep breaths, the patient will
begin to feel the analgesic effect. Full potential is reached at approximately 1 – 2
minutes.

Side effects can include: sedation, nausea, headache, dizziness

With prolonged use bone marrow depression and neurological damage can result,
with symptoms including neutropenia and neuropathy respectively. A daily FBC and
B12 is recommended.

If entonox is to be used, it must be prescribed on the patient’s medication chart.

5.2 Methoxyflurane (Penthrox)

The following guideline is for the administration of inhaled Methoxyflurane (Penthrox) to
patients at Waikato Hospital in order to provide short-term analgesia during acute pain
episodes.

Penthrox can be administered in specially designated areas of the hospital by
nursing/medical staff who have undergone specific training in its use. If your work place
has not been educated in the use of Penthrox but you feel it could benefit your patients,
please contact the Inpatient Pain Service to discuss and arrange a training session

Methoxyflurane is an inhalational anaesthetic agent that provides profound analgesia at
concentrations that do not cause unconsciousness. It is no longer used for general
anaesthesia because prolonged exposure to anaesthetic doses is associated with renal
toxicity. No cases of renal toxicity have been reported with analgesic doses.
Methoxyflurane alters the perception of pain and reduces suffering. Patients describe
‘floating separately from the pain’ or feeling ‘discomfort rather than pain’. There is a
degree of amnesia related to the painful event. At analgesic doses there is no clinical
depression of respiration or the circulation.

Methoxyflurane is self-administered via a Penthrox inhaler only. It enters the lungs in the
form of a vapour. It is rapidly distributed into the blood and tissues. 50-70% of the dose
is metabolised in the liver and kidneys, the remaining drug is exhaled unchanged.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 43 of 70
Analgesia commences after 6-8 breaths. As the drug is self-administered, the patient
spontaneously ceases administration should excessive drowsiness occur and restarts if
required. Methoxyflurane is not flammable or explosive.

Indications

         •    Dressing Changes: Burns/ necrotising fasciitis/ surgical wounds
         •    Minor procedures: Superficial abscess drainage/ Manipulation of greenstick
              fractures/ Biopsies/ Adjunct to local anaesthesia for termination of early
              pregnancies/ Chest drain insertion or removal
         •    Radiation Oncology: Removal of brachytherapy rods
         •    Interventional radiology: Vascular access/ drainage of collections
         •    Physiotherapy: Mobilisation post- joint replacements, other fractures, burns
         •    Anaesthesia: Insertion of regional anaesthesia blocks and vascular access

Presentation

3 mL ampoule to be added to Penthrox inhaler as directed

Dose

12 years and over: Maximum volume of 6mL/ day and 15mL/week.
Under 12 years: Maximum volume of 3mL/day and 9mL/week.

3 mls will last approx 20-25 min of continuous use; 6 mls will last 50-60 min
Administration on consecutive days is generally not recommended.

Contraindications

•   Inadequate patient cooperation/understanding
•   Pts < 8yr/age
•   Known renal dysfunction
•   Possible renal dysfunction (including all diabetic patients) without evidence of
    normal creatinine
•   Previous liver dysfunction related to volatile anaesthesia
•   Malignant hyperpyrexia (MH) / Family history of MH without negative personal test
•   Decreased level of consciousness
•   Raised intracranial pressure
•   Significant cardiovascular compromise
•   Concurrent administration of drugs with known nephrotoxic potential, in particular:
    tetracyclines, gentamycin, kanamycin, colistin, polymyxin b, cephalodrine,
    amphotericin b.
•   Pre-eclampsia
•   Psychosis

If in doubt, please discuss with Inpatient Pain Service



Precautions


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 44 of 70
•    Concurrent sedative drugs
•    Mild renal impairment
•    Concurrent administration of drugs with know enzyme inducing properties, in
     particular barbiturates
•    Do not expose to temperatures >40ºC

Drug/drug interactions and incompatibilities

• Co-administration with nephrotoxic drugs, as listed above.
• Co-administration with enzyme inducing drugs, as listed above

Adverse effects

•    Headache
•    Nausea
•    Marked sedation
•    Coughing
•    Dizziness
•    Malignant Hyperpyrexia (MH)

Rescue medication if needed: Dantrolene for Malignant Hyperpyrexia under direct
instruction of Department of Anaesthesia or Intensive Care

1.       Administration

Doctor or Registered Nurse - must hold current certification for administration of
Methoxyflurane. To achieve this, attendance at a penthrox training program and
successful completion of the subsequent test is required.

2.       Monitoring

Blood Pressure, O2 Saturation, Heart Rate, Sedation level (verbal contact) prior to
commencing then every 5 minutes until stable post procedure
Baseline temperature then 15min and 30 min post procedure


3.       Patient advice/ explanation

Explain planned procedure and give patient a copy of Penthrox Consumer
Information leaflet to read. Ensure understanding.

Demonstrate use with un-primed inhaler.

Ensure:
• Patient understands why and how drug is to be used.
• Patient expects characteristic smell/ taste.
• Patient understands how to administer stronger concentration if required.
• Patient alert to potential contraindications/side effects.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 45 of 70
•    Patient understands they should not drive or operate complex machinery after
     using device.

4.       Preparation and administration
a.   Ensure access to a supply of oxygen (wall/ cylinder)
b.   Know how to access the emergency trolley should it be required
c.   Check baseline temperature
d.   Establish monitoring: NIBP, pulse, SpO2, sedation. Take baseline observations
     and repeat at 5 min intervals during procedure. NB. Assessment of sedation
     throughout ensuring verbal contact is sufficient.
e.   Check activated charcoal (AC) chamber is pre-inserted into dilutor hole of inhaler.
     This is to absorb exhaled vapour and minimise staff exposure.
f.   Tilt penthrox inhaler to 45 degrees and slowly pour all of the contents of the 3ml
     bottle into base of inhaler while rotating the inhaler
g.   Shake lightly to ensure even distribution throughout inhaler
h.   Place wrist loop around patient’s wrist.
i.   Advise patient to inhale and exhale through mouthpiece of inhaler slowly at first,
     then deeper breaths. Warn them to expect the sweet smell/ taste.
j.   Pain relief should be obtained in 8-10 breaths (may take up to 2 minutes); if
     stronger pain relief is required advise patient to cover dilutor hole on top of AC
     chamber with a finger when inhaling.
k.   Patient can use inhaler continually or intermittently during procedure.
l.   If procedure lasts more than 20-25 mins a further 3 mls of penthrox may be
     required
m.   If at any time the patient seems to be over-sedated (verbal contact is lost) remove
     the inhaler device from patient, make sure the patients’ airway remains clear, and
     that the patient continues to breathe well. Once their level of consciousness
     improves they can continue to use the inhaler as needed.

     Notes:
     At no point during the administration should the patient be left unattended.
     Unconsciousness should never be deliberately induced

5.     After procedure
a. If no further procedures are anticipated for this patient place used inhaler in
   supplied sealed plastic bag and dispose of into clinical waste bin.
b. If further procedures are likely attach patient identification sticker onto inhaler and
   place the inhaler in the sealed bag provided.
c. Store the device in an appropriate environment eg. Locked dispensary
d. Continue observations every 5 mins until stable
e. Recheck temperature at 15 min and 30 min post-procedure
f. A temperature increase of greater than 2ºC per hour or cardiovascular instability,
   especially sustained tachycardia, may indicate malignant hyperpyrexia – contact
   the acute pain service (APS ph 021759512) urgently. If the APS is not contactable
   then ring the duty Anaesthetist (ph23322).




6.       Follow-up Documentation


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 46 of 70
Once patient has recovered from procedure ask them to rate the effectiveness of the
analgesia as instructed in the Methoxyflurane data collection form. Complete the rest
of the form and fax/send to Inpatient Pain Service (fax via anaesthetic secretary ext.
8761). Retain a copy of the completed form in the patients’ notes The information is
important both as a record of administration and to allow the IPS to optimise the use of
Penthrox analgesia in the hospital.

References
    •   Penthrox (Methoxyflurane) inhalation product information, Medical
        Developments International Ltd
    •   Penthrox Consumer Information leaflet, Medical Developments International
        Ltd




Appendix I Acute Pain: Adverse Physiological and Psychological effects




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 47 of 70
“Pain is a more terrible Lord of mankind than Death itself” – Albert Schweitzer

Effective management of acute pain is required not only for ethical reasons (a basic
human right) but to modify the response to injury (Cousins 2000; Cousins et al. 2004)

The magnitude of the injury response is proportional to the degree of tissue damage.
(Cousins 1989).

This injury response leads in turn to a number of physiological changes that promote
catabolism, increased sympathetic activity, immunosuppression, and other adverse
effects.

The psychological effects of acute pain are just as harmful although they may be less
obvious. They interact with the physical changes and often form part of a vicious
cycle. (Dinarello 1984; Cousins & Phillips 1986)

Figure 1: The Injury Response


Injury                                  Intermediate                               Injury response


                                                                                   Inflammation
Post-operative pain                      Acute phase
                                         ‘cytokines’ (e.g.)                        Hyperalgesia
                                         Interleukin 1,6)
Surgical trauma                                                                    Catabolism
                                         Neural
Psychological                                                                      Other systems
                                         Humoral                                   adaptations
Environmental
factors                                  Metabolic                                 Physical/mental
                                                                                   deactivation
Other factors (e.g.                      Immune
drugs)




Physiological effects

Pain and injury result in activation of both peripheral and central nervous systems.
This ‘stress response’ evoked includes a systemic metabolic response due to release
of neuroendocrine hormones and the local release of cytokines at the site of injury
leading to physiological alterations in all major organ systems.

Cardiovascular — Pain can activate sympathetic efferent nerves leading to increase in
heart rate, inotropy and blood pressure. This increases myocardial oxygen demand and
reduces myocardial oxygen supply, increases the risk of cardiac ischaemia, particularly in
patients with pre-existing cardiac disease.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010     Page 48 of 70
Gastrointestinal — increased sympathetic activity can also reduce gastrointestinal mobility and
contribute to ileus.

Respiratory — severe pain after upper abdominal and thoracic surgery contributes to
an inability to cough and a reduction in functional residual capacity. This results in
atelectasis and ventilation–perfusion abnormalities, hypoxaemia, and an increased
incidence of pulmonary complications.

Immune function and coagulation — The stress response also contributes to
suppression of cellular and humoral immune function and a hypercoagulable state
following surgery. Both of these can contribute to post-operative complications (Lieu et
al. 1995).

Patients at greatest risk of adverse outcomes from acute unrelieved pain include the
very young, the elderly patient, those with concurrent medical illnesses, and those
undergoing major surgery.

Effective analgesia is capable of modifying many of the pathophysiological responses
to injury, thereby assisting recovery (Kehlet 1999; Kehlet & Dahl 2003).

Psychological changes:

Failure to relieve acute pain may result in anxiety, inability to sleep, demoralisation, a
feeling of helplessness, loss of control, and inability to think and interact with others. In
the most extreme situation, it can lead to loss of autonomy.

In some forms of acute pain psychological responses in the acute phase may be
major determinants of progression to a persistent phase.

Progression of Acute to Persistent pain

There is a well-defined association between acute and persistent pain. Acute pain
states, which may progress to persistent pain, include post operative and post-
traumatic pain, acute back pain, and acute zoster.

There is some evidence that specific early analgesic intervention may reduce the
incidence of persistent pain, after surgery.

Risk factors that predispose to the development of persistent post-surgical pain
include the severity of pre- and post-operative pain, intraoperative nerve injury, and
psychological vulnerability.

References:

Cousins MJ (1989). JJ Bonica lectures. Acute pain and the injury response: immediate
and prolonged effects. Reg Anaesth Pain Med 14: 162–178
Cousins MJ (2000). Relief of acute pain: a basic human right? Med J Aust 172: 3–4.
Cousins MJ, Brennan F, Carr DB (2004). Editorial: Pain relief a universal human right.
Pain 112: 1–4.



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 49 of 70
Kehlet H (1999). Acute pain control and accelerated post operative surgical recovery.
Surg Chn North Am 79: 431–443.
Dinarello C (1984). Interleulin-1. Rev Infect Dis 6: 51–95.
Liu S, Carpenter RL, Neal JM (1995). Epidural anaesthesia and analgesia: Their role
in postoperative outcome. Anesthesiology 82: 1474–1506.
Kehlet H & Dahl JB (2003), Anaesthesia, surgery and challenges in postoperative
recovery. Lancet 362: 1921–1928.




Appendix II – Opioid Conversion Table



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 50 of 70
Equianalgesic doses: 10mg morphine is roughly equivalent to:


OPIOID                               IV DOSE (mg)                          ORAL (mg)

MORPHINE                             10mg                         30mg

OXYCODONE                                      15mg                        20-30mg

PETHIDINE                            100mg                                 400mg

FENTANYL                             150-200mcg                   n/a

TRAMADOL                             100mg                                 100mg


Ref: Acute Pain Management (2nd ed); Macintyre/ Ready; 2005




Appendix III PCA Pump Protocols



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 51 of 70
 Waikato DHB Bodyguard 575 Pain Pump - Updated Medication Library 2009

Protocol Full Protocol                                                                    Select Protocol
A        Morphine 0.5mg bolus, 5min lockout, 6mg/hr                                       Mor 0.5mg 5min 6mgh
         limit
B        Morphine 1 mg bolus, 5min lockout, 12mg/hr                                       Mor 1mg 5min 12mgh
         limit
C        Morphine 1.5mg bolus, 5min lockout, 18mg/hr                                      Mor 1.5mg 5min 18mg
         limit
D        Morphine 2mg bolus, 5min lockout, 24mg/hr                                        Mor 2mg 5min 24mg
         limit
E        Morphine Custom                                                                  Morphine Custom
F        Fentanyl 10ug bolus, 5min lockout, 60ug/hr limit                                 Fent10ug 5min 60ugh
G        Fentanyl 20ug bolus, 5min lockout, 120ug/hr                                      Fent20ug 5min 120ugh
         limit
H        Fentanyl 20ug bolus, 5min lockout, 240ug/hr                                      Fent20ug 5min 240ugh
         limit
I        Fentanyl Custom                                                                  Fentanyl Custom
J        Tramadol 10mg bolus, 5min lockout, 120mg/hr                                      Tram10mg5min120mg
         limit
K        Tramadol 10mg bolus, 10min lockout, 60mg/hr                                      Tram10mg10min60mg
         limit
L        Tramadol Custom                                                                  Tramadol Custom
M        Procedure Custom                                                                 Procedure Custom
N        Ketamine Infusion                                                                Ketamine Infusion
O        Alfentanyl 200ug bolus, 3min lockout, 2000ug/hr                                  Alfen 200ug3min 2mgh
         limit
P        Pethidine Custom                                                                 Pethidine Custom
Q        Oxycodone Custom                                                                 Oxycodone Custom
R        Methadone Custom                                                                 Methodone Custom
S        Paediatric NCA(Nurse Controlled)                                                 NCA Paediatrics
         Rate 0mls per hour - Max Rate 2mls per hour
         This allows the Nurse to titrate the basal rate
         between 0-2ml per hour depending on
         prescription, child’s pain and condition.
         Bolus 1ml, 20min lockout, 5ml/hr limit
T        Paediatric PCA                                                                   PCA Paediatrics
         Rate 0ml per hour – Max Rate 1ml per hour. This
         allows the Nurse to titrate the basal rate
         between 0-1ml per hour depending on
         prescription, child’s pain and condition.
         Bolus l ml, 5min lockout, 10ml/hr limit
U        Custom                                                                           Custom

 Note: If patient prescription is not in the drug library only alter the Custom
 Protocols
 Appendix IV Troubleshooting Guidelines



                                                                               st
 WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010    Page 52 of 70
Appendix V Guidelines for the Treatment of PONV (Post-operative nausea and
vomiting)


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 53 of 70
Risk factors for PONV

    •    History of PONV or motion sickness
    •    Emetogenic drugs post-operatively, especially opioids
    •    Surgery type e.g. laparoscopic, gynaecological, total joint replacement,
         strabismus, tonsillectomy, adenoidectomy, otoplasty, orchidopexy, middle ear,
         any ENT
    •    Pain (especially visceral and pelvic) and anxiety
    •    Movement
    •    Age (peak PONV risk 11–14 years old)
    •    Stage of menstrual cycle  PONV during first 7 days cycle
    •    Concurrent illness
    •    Obesity

General Principles to reduce PONV after Ward admission

    •    Movement care – feet first
    •    Decompression of stomach with NGT may be helpful
    •    Remove patient from company of other patients who are vomiting
    •    Keep hydrated and maintain BP
    •    Keep pain and anxiety well managed
    •    Consider providing take home antiemetic for Day Surgery patients who have
         had PONV problems
    •    PONV can be reduced if first fluid intake is delayed

Treatment Procedure

    •   Administer first drug in sequence as soon as possible for treatment of Post-
        operative nausea and/or vomiting (PONV)
   • Assess each treatment 15 min after its administration;
        If effective, continue use with the drug prn
        If PONV has not improved, or if unacceptable side effects are experienced, give
        the next drug in the sequence (and assess 15 minutes later)
For first line agent (Cyclizine)
   • If 12.5mg - 25 mg of Cyclizine is partially effective or is initially effective but
        loses its effectiveness within 4 hours.
   • If PONV recurs within 4 hours of administration of 50 mg of cyclizine, give the
        next drug in the sequence (and assess 15 minutes later)
   • If effective, continue with this agent prn

Subsequent Agents

    •    If the second and third line agent was initially effective, but appears ineffective
         on repeat administration, or loses its effectiveness before another dose can be
         given (e.g. ondansetron loses effectiveness at 5 hours rather than 8 hours),
         assume the initial effectiveness was due to the combination of this drug plus
         the previous agent. This combination should therefore be administered prn.
    •    If the combination is not effective, or if unacceptable side effects are
         experienced, give the next drug in the sequence.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 54 of 70
    •    Seek help if no drug options remain: refer to medicines.


    TREATMENT GUIDELINES

    Adult Drug Options

    (Administer according to the Treatment Procedure)


                                           Cyclizine IV 12.5–50 mg
                                           q4-8hprn (max 150
                                           mg/day) Try 25 mg first
                                           unless patient old/frail
                                           then try 12.5mg


GI Surgery/Gastroparesis                                                   All            other      Surgery



    Metoclopramide 10 mg IV q6h                                Ondansetron 4 mg IV
    prn                                                        q8h prn



    Ondansetron 4mg IV q8h prn                                 Droperidol 1 mg q6h prn
                                                               (Consultant only)




     Droperidol 1 mg IV q6h prn
     (Consultant only)




Appendix VI Anticoagulation and Epidural Anaesthesia/Paravertebral Analgesia

The combination of anticoagulant therapy and epidural/ spinal analgesia poses an
increased risk to the patient of spinal haematoma formation. The peak period of risk


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 55 of 70
for haematoma occurs at the insertion and again at the removal of the epidural
catheter. Below are some recommended guidelines in relation to anticoagulant
therapy to minimise this risk however, each case needs to be evaluated on its own
benefit or risk.

LOW MOLECULAR WEIGHT HEPARINS:
e.g. clexane and fragmin (once-daily prophylactic doses)
Epidural catheter placement should not occur until at least 12 hours (preferably 18-24
hours) has passed since the previous standard prophylactic dose. Similarly, at least
12 (preferably 18-24) hours should elapse before removing the epidural catheter. The
first post operative dose should be given 6-8 hours post operatively with subsequent
doses every 24 hours after that. From a pain management point of view in Waikato
DHB, early to mid afternoon timing for the daily dose allows for the patient to be
reviewed on the morning pain round and an optimal time to have passed since the
previous dose to minimise the risk of haematoma formation.
Following removal of the catheter 4 hours should pass before reinstituting the
anticoagulant.

Full anticoagulant doses of LMWH for treatment of DVT, pulmonary embolism or
unstable angina for instance will result in prolonged anticoagulant effect and 24-48
hours should pass prior to siting or removing an epidural catheter. It is recommended
that if the clinical situation permits it, prior to insertion of a neuraxial block factor Xa
levels should be checked and the results discussed with a haematologist.

UNFRACTIONATED HEPARIN:
e.g low dose subcutaneous heparin (5,000 IU 8-12 hrly or 7,500 IU 12 hrly)
Wait 4-6 hours after dose before instituting a spinal or epidural block or removing the
catheter as there may be a transient rise in APTT.

HEPARIN INFUSIONS:
Stop heparin infusion 4-6hrs pre-op
Check APTT 90 mins pre-op. If less than 40 seconds, and in the absence of other
contraindications, neuraxial anaesthesia can be safely administered

ORAL ANTICOAGULANTS:
e.g warfarin
Full anticoagulation is an absolute contraindication to spinal or epidural block.
Discontinue established therapy at least 4-5 days prior to neuraxial blockade.
Recommend INR of <1.5 for 2 consecutive days (or <1.5 and falling) prior to instituting
a block or removing a catheter.

ANTIPLATELET AGENTS:
NSAIDS alone do not significantly increase the risk of spinal haematoma. However, if
they are used in conjunction with other anticoagulants they should certainly be
considered a risk factor.

Recommended time intervals between                              discontinuation          of    other   antiplatelet
medications and neuraxial blockade are:
Tirofiban and Eptifibatide 8 hours
Abciximab 48 hours


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010        Page 56 of 70
Clopidogrel 7 days
Ticlopidine 14 days

FIBRINOLYSIS AND THROMBOLYSIS:
Neuraxial blockade NOT recommended for patients receiving these drugs. No safety
data available re time intervals required for safe catheter insertion. Discuss with
haematologist.

NEW ANTICOAGULANTS:
Caution advised as limited data available re safe timing intervals between drug
administration and instituting any major regional analgesia.

HERBAL THERAPY:
e.g garlic, ginko, ginseng
Currently, no specific concerns about their use with neuraxial blockade.

ANY PATIENT receiving anticoagulant prophylaxis and epidural analgesia
should be monitored closely for signs of cord compression due to epidural
haematoma formation.
Symptoms : New onset of backpain (may or may not be present)
           Progressive weakness or numbness in lower extremities
           Bowel or bladder dysfunction

If spinal haematoma is suspected, diagnostic imaging (MRI) and possible
surgical intervention must be performed rapidly to reduce the risk of permanent
paralysis.

References:

Horlocker TT, Wedel D J, Benzon H et al (2003) regional anaesthesia in the anticoagulated
patient: defining the risks (the second ASRA Consensus Conference on Neuraxial
Anaesthesia and Anticoagulation). Reg Anesth Pain Med 28:172-97

Acute Pain Management: Scientific Evidence second edition 2005 p117-119

Priestly, M. Central neural blockade (CNB) in anticoagulated patients (draft)
http://www.westmeadanaesthesia.org

Schunemann HJ; CookD; Grimshaw J; Liberati A; Heffner J; Tapson V; Guyatt G
Antithrombotic and thrombolytic therapy: from evidence to application:the Seventh ACCP
Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004 Sept; Vol.126 pp688S-
696S.

Scottish Intercollegiate Guidelines Network Prophylaxis of Venous Thromboembolism section
7: Spinal and epidural block. Dec 2002 http://www.sign.ac.uk

Checketts MR; Wildsmith JAW; Central nerve block and thromboprophylaxis – is there a
problem? BJA 82 (2): 164-7 (1999)
Appendix VII Ketamine/Midazolam for Ward Based Procedures

Purpose



                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 57 of 70
          •    To provide optimal and safe analgesia during repeated painful procedures
               on the ward e.g dressings and wound debridements on burns patients.
          •    To avoid unnecessary trips to the operating theatres which would require
               pre-op fasting at a time when prolonged periods of starvation could be
               detrimental to patient healing and immunity.
          •    To enable clinical staff (nurses, physiotherapists, occupational therapists)
               to provide treatments and therapies in a time efficient manner while the
               patient is suitably analgesed.
          •    To minimise adverse psychological effects of patients’ repeated exposure
               to painful stimuli.

Level of competency required

    IV Opioid certification with IV Midazolam certification.

Equipment needed
  Functioning luer
  50 ml BD syringe
  PCA tubing and pump
  Monitoring equipment ( BP, HR, Oxygen saturations, RR)
  Drugs: 10 mls of 1mg/ml midazolam (10 mg)
           2 mls of 100 mg/ml ketamine (200 mg)
            8 mls of normal saline
  This will give a 20 ml volume containing 10 mg/ml ketamine and 0.5 mg/ml
  midazolam.
  Occasionally this prescription may be adjusted (e.g. midazolam omitted) on clinical
  grounds so check PCA form.

    Anexate (Flumazenil) available as the antidote to midazolam.
    Emergency trolley on ward
    Oxygen in room and facemask, tubing, ambubag, guedel (oropharyngeal) airway
    Suction available if required



                    Action                  Rationale
     •   Talk with patient and discuss         This should reduce the anxiety of
         with them the reasons why             the patient who will know what to
         ketamine and midazolam could          expect from these drugs.
         be      an      effective     drug
         combination with which to treat       It allows procedures to be done on
         the pain they may experience          the ward rather than in theatre.
         during       major        dressing
         changes/procedures.                   It also allows the patient the option
         i.e. Patient remains awake, but       not to have these drugs.
         should        have         minimal
         recollection of events later on.
         Staff can do a thorough job
         without causing severe pain to
         the patient.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 58 of 70
         Explain the possibility of side
     effects
         e.g hallucinations, excessive
         salivation, nausea and vomiting
         with ketamine.

         The patient may feel drowsy,
         but sedation is likely to be
         minimal.

         Ensure full education is given
         and allow the patient the
         opportunity to give their verbal
         consent.

     Contact the Inpatient Pain Service:                 To ensure there is immediately
     bleep 20439 (or Duty anaesthetist                   available help should difficulties arise.
     at weekends: direct dial 23322) to                  NO PROCEDURE SHOULD BE
     advise them that a procedure is                     UNDERTAKEN          WITHOUT          THIS
     planned.                                            BACKUP

                                                         There must be satisfactory IV access
     Check for a functioning luer.                       for PCA.

                                         The PCA can be commenced
     Using aseptic technique and while the dressing trolley is being set
     correct                             up.
     equipment, prepare ketamine/
     midazolam PCA as charted. RN
     with appropriate certification and
     RN/EN with IV generic cert should
     prepare   this    prescription   in
     advance of the dressing.


     Preferably the same senior nurse                    This will ensure continuity of care,
     would be involved on each                           and an understanding of the patient’s
     occasion and will inform the Acute                  medication       requirements        and
     Pain Service pre-procedure. (It is                  responses to it.
     recommended       that    wherever
     possible    procedure/therapy   is
     performed in the morning).
     Stop any other IV/SC analgesia for This reduces interaction with other
     the duration of the ketamine/      potentially sedating drugs which could
     midazolam PCA                      compromise       patient    level   of
                                        consciousness and respiratory rate.
     Keep excess noise and disruption Some level of disorientation and/or
     to a minimum. Turn down TV and sedation is likely to be experienced by
     radio sets and keep voices lowered the patient. It is beneficial to keep


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 59 of 70
     if possible.                                        stimulation to a minimum.

     Commence PCA 20 minutes prior                       Starting the PCA early allows for
     to the commencement of the                          optimal analgesic drug levels to be
     procedure and advise the patient                    reached prior to the painful stimuli of
     to start using the PCA several                      dressing/procedure.
     times prior to the dressing and
     throughout the procedure as
     required.

     Commence observations with start To ensure patient safety, and monitor
     of PCA. Q5 min SpO2, BP, RR, patient response to drugs.
     sedation score up until 30 minutes
     post-procedure.        Longer     if
     indicated. Watch particularly for
     any periods of apnoea, airway
     obstruction and desaturation, also
     hallucinations. The patient may be
     disoriented for several hours after
     procedure.

     If any untoward events occur, To provide rapid intervention in the
     follow                              unlikely event of problems arising.
     trouble shooting guidelines on PCA
     chart and notify a member of the
     Inpatient Pain Service (bleep
     20439), or cell phone (021) 759-
     512. If during the weekend or out
     of normal hours call the duty
     anaesthetist      (23322)       for
     assistance.

     Following the procedure, discard To provide adequate analgesia and
     any unused drug remaining in the dispose of any unused medication
     syringe by disposing down a safely.
     suitable drainage system and
     reconnect     any       previously
     prescribed PCA as charted.

     Continue monitoring patient, as To provide a safe post procedural
     above for 30 minutes post environment.
     procedure and until the patient
     condition is satisfactory i.e easily
     rouseable, no hallucinations, vital
     signs       within       acceptable
     parameters.

     Question the patient several hours To monitor effectiveness of treatment.
     post-procedure to evaluate the
     patient’s    recollection      and To enable changes in treatment that


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 60 of 70
     impression         of    the     experience. need to be made                                  for   future
     Document.                                    dressings/treatment.




Appendix VIII Acute Pain Management in the Opioid-Tolerant Patient




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010           Page 61 of 70
Three main groups of opioid-tolerant patients are encountered in surgical and other
acute pain settings:
• Patients with chronic cancer and non-cancer pain being treated with opioids (some
   of whom may exhibit features of opioid addiction).
• Patients with a substance abuse disorder either using illicit opioids or on an opioid
   maintenance treatment programme.
• Patients who have developed acute opioid tolerance due to perioperative opioid
   administration, particularly opioids of high potency.
In all cases managing acute pain in these patients requires close liaison with other
treating clinicians.

The main aims of treatment in these patients are:
• To provide adequate analgesic
• To prevent withdrawal — remember in the case of substance abuse, polysubstance
  abuse is common and they may be at risk of withdrawal from benzodiazepines and
  alcohol especially.
• Symptomatic treatment of any affective or behavioural disorders.

Opioid Doses

These patients are likely to require much higher doses of opioid in the acute pain
setting.
The doses of opioid prescribed should be based on their current opioid use, so
knowledge of the equianalgesic doses of opioids is required (see appendix II).

Pre-op

Regardless of the analgesic techniques, perioperative management begins with
pre-operative administration of the patient’s normal daily maintenance opioid
dose prior to operation.

Post-op

In non ambulatory patients, IV PCA may be the most useful analgesic technique,
provided pain intensity and opioid consumption are carefully monitored.
If/when patients can take oral medication they should continue with their usual oral
opioid.
If patients are unable to absorb oral medications, their background requirements must
be provided by an equianalgesic dose of the same or another opioid background via
an IV infusion.
It may be of benefit to check pre-admission opioid doses with the patients’ Doctors or
Pharmacists to prevent incorrect doses being prescribed.

Some examples of PCA calculations

The following examples assume that the patients are unable to take their normal
maintenance oral opioid.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 62 of 70
Example One
A patient taking 60 mg BD M Eslon prior to admission and is to have PCA morphine
after surgery.

Oral 60 mg BD                                = 120 mg in 24 hrs
IV equivalent                                = 40 mg in 24 hrs
                                             = 2 mg/hr (approx)
Therefore PCA morphine bolus                 = 2 mg
And background infusion                      = 2 mg/hr



          Example Two
          Note equianalgesic doses of methadone are more difficult to accurately calculate due
          to the long and variable half life of oral methadone.

          A patient taking 60 mg methadone daily prior to admission and is to have PCA
          morphine after surgery.

           IV morphine                                 = equivalent 40 mg
                                                       = 2 mg/hr (approx)
          Therefore PCA morphine bolus                 = 2 mg
          And background infusion                      = 2 mg/hr


              Example Three
              A patient is taking 20 mg BD Oxycontin prior to admission and is to have PCA
              morphine after surgery.

              20mg BD                                       = 40 mg in 24 hrs
              IV morphine equivalent                        = 20 mg in 24 hrs
                                                            = 1 mg/hr (approx)

              Incomplete cross-tolerance with morphine therefore need to reduce dose by 50%.
              Therefore is really               = <1 mg/h
               PCA morphine bolus               = normal aged-based dose.
               And background infusion          = 0 mg/hr


Requirements may be too high to change immediately to oral opioids only, and
conversion over a few days may be needed. The patients’ maintenance CR opioid or
methadone doses are usually not increased unless long-term requirements are likely
to be higher and the original prescriber is consulted.

For Example:
Day 1: Restart usual oral opioids (CR opioids or methadone) and cease any PCA
background infusion.

Day 2: Replace half of the immediate-last-24-hr-PCA morphine requirements with oral
continuous release opioid (oxycontin and morphine MST) and reduces PCA bolus
PCA bolus dose by half.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 63 of 70
Day 3: Calculate additional CR opioid required to replace last 24hr PCA morphine
requirement, and cease PCA.
OR repeat Day 2 step as needed until doses are such that oral opioids only can be
used. May also need to chart small additional doses of immediate release opioid, i.e.
5–10 mg of Oxynorm or morphine elixir three hourly for breakthrough pain.

Example
A patient using 250 mg morphine/day by PCA. The background infusive is running at 4
mg/hr and the bolus dose is 4 mg. The patient normally takes LA-Morph 100 mg BD.

Day 1:
  • Cease background and restart LA-Morph 100 mg BD.


Day 2:
  • The patient’s PCA morphine use in now 180 mg morphine in last 24 hours.
  • Half of this is 90 mg, which can be taken to equal 90 mg Oxycodone in 24
       hours.
  • Order Oxycontin 40 mg BD or 30 mg tds.
  • Reduce PCA bolus dose to 2 mg.

Day 3:
  • The patient’s PCA morphine use is now only 60 mg morphine in last 24 hours.
       This is equivalent to 60–120 mg oral Oxycodone,
       i.e. 20 mg tds or 30 mg BD oxycontin.
  • PCA can be stopped.


Adjuvant Agents:

Ketamine: The NMDA receptor is involved in the development of opioid tolerance and
a low-dose ketamine infusion may benefit or reduce opioid requirements in some
patients.

Clonidine: May help minimise withdrawal symptoms and also has some analgesic
activity.
Oral, Sc, or clonidine patches may be used.

Neuraxial Opioids: Have been used effectively in opioid-tolerant patients. Higher
doses may be required. Will not prevent symptoms of opioid withdrawal.

While multimodal analgesia regimes will be a benefit, these patients are at risk of
opioid withdrawal and incomplete analgesia, if at least the maintenance opioid
requirements are not met.

Liaison with all clinicians involved in the treatment of the opioid tolerant-patient is
important. Discharge planning should involve communication with the primary
physician, possibly community alcohol and drug service (CADS) as well as patient
education and support.


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 64 of 70
      Appendix IX Acute Neuropathic Pain

      Neuropathic pain has been defined as ‘pain arising as a direct consequence of a
      primary lesion or disease affecting the somatosensory system’ (Treede, Jensen,
      Campbell et al., 2008)

      Nerve injury is a risk in many surgical procedures, and may present as acute
      neuropathic pain in the post-operative period or following trauma.

      Some neuropathic pain subsides spontaneously, however the majority of these have
      persistent pain at 12 months, suggesting that early analgesic interventions may
      reduce the incidence of chronic pain (often neuropathic pain) after some operations
      (e.g. thoracotomy, amputation).

      The prompt diagnosis of acute neuropathic pain is therefore important.

      Features in the pain history that may suggest a diagnosis of neuropathic pain include:

i.                   1. Lack of or less responsiveness to opioids (especially morphine).
                     2. Persistent pain or a new pain emerging later.
                     3. Pain descriptors such as burning, shooting, and stabbing.
ii.                  4. The paroxysmal or spontaneous nature of the pain which may have no
                     clear precipitating factors.
                     5. The presence of dysaesthesias (spontaneous or evoked unpleasant
                     abnormal sensations), hyperalgesia (increased response to a normally
                     painful stimulus), allodynia (pain due to a stimulus that does not normally
                     evoke pain, such as light touch), or areas of hyperaesthesic and regional
                     autonomic features (changes in colour, temperature, and sweating), and
                     phantom phenomena.

       Management

       Is based on extrapolation of data from the chronic pain setting.

       Initial Treatment

       Guidance can be obtained from the Inpatient Pain Service (IPS). Agents that may be
       used:

       First-line:

       (a)     Tricyclic Antidepressant (TCAs). Better results are obtained with the ‘older’
               TCAs, and Amitriptyline is still the most commonly used. The newer SSRIs are
               not as effective. Initial doses should be small then increased if needed, every
               3–4 days as needed. It can take 6 – 8 weeks for an adequate trial of treatment
               but benefits may be gained earlier than this.

               Check the patient is not already on another antidepressant and be aware of any
               contraindications/precautions, such as ischaemic cardiac disease or ventricular
               conduction abnormalities, to their use.


                                                                                    st
      WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 65 of 70
         Amitriptyline             10–25 mg nocte (before 8pm) if < 60 years.
                                   10 mg nocte (before 8pm) if > 60 years.

 (b)     Calcium Channel α2-∂ antagonists – gabapentin and pregabalin

These drugs bind to voltage-gated calcium channels and inhibit excitatory
neurotransmitter release. Gabapentin’s pharmacokinetics are non-linear (due to
saturable absorption meaning that as the dose is increased, its bioavailability drops).
Pregabalin is a better alternative but is not funded. Side effects include sedation,
fatigue, dizziness, headache, nausea.

Recommended gabapentin starting dose:                             100 – 300mg nocte
Recommended pregabalin starting dose:                                   150mg a day, taken in divided
doses

Precautions:
   • Use reduced doses in patients with impaired renal function, on dialysis
    •    Avoid abrupt withdrawal of the drug
    •    Pregnancy – benefits must outweigh the risks of treatment, and ensure folic
         acid 5mg supplementation)
    •    Concommitant use of another AED


Funding – gabapentin is not funded outside hospital. If commenced for the treatment
of neuropathic pain, unless the patient has tried and failed on or not tolerated a TCA,
funding will not be approved.

Second line:

 (c)     Tramadol but less effective than strong opioids such as oxycodone

Less risk of abuse with tramadol, but also lowers the seizure threshold and can
interact with other medications such as SSRIs, SNRIs, TCAs to cause serotonin
toxicity, which is potentially fatal.

Start with 50mg once or twice daily and then increase gradually as needed/tolerated to
a maximum of 600mg/day. Remember to use smaller doses in the elderly and those
with renal or hepatic impairment/failure.

 (d)     Strong opioids – oxycodone, methadone, morphine

Should not be routinely used as first-line and instead should be reserved for patients
who do not respond to the first-line medications as above.
Issues are more with longer term use and include: risk of hypogonadism, immunologic
changes, opioid misuse/abuse




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 66 of 70
Other treatments include (but should be discussed with a pain consultant):

 (e)     Clonazepam. Starting at low dose 0.25–0.5 mg nocte, increasing if necessary
         to 1–2 mg nocte. Side effects include sedation, and this may help sleep.
 (f)     Clonidine - Small IV boluses 15–30 mcg followed by a clonidine patch
         (clonidine TTS1).
 (g)     Ketamine via infusion 4mg/mL
 (h)     Lignocaine via infusion
 (i)     Capsaicin
 (j)     Mexilitine

 Referral to the outpatient Chronic Pain Service is usually required for further
 management advice and follow-up.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 67 of 70
Appendix X Neuropathic Pain Assessment Tools

Several tools are available to distinguish nociceptive from neuropathic pain. Tools that
combine self-report and physical examination are more precise than simply self-report.
The two tools below have been validated across many settings and in different
countries. They are the Leeds Assessment of Neuropathic Symptoms and Signs
(LANSS) and the Douleur Neuropathique en 4 questions (DN4) which was originally
developed in French (hence its name) but is now translated into English. The latter
tool, DN4 is easier to score and hence may possibly be the better tool to use.

LANSS Pain Scale

                                       Symptom/Sign                                                Score       for
                                                                                                   “yes”
Does the pain feel like strange unpleasant sensations? (e.g pricking,                                      5
tingling, pins/needles)
Do painful areas look different? (e.g. mottled, more red/pink than                                         5
usual)
Is the area abnormally sensitive to touch? (e.g. lightly stroked, tight                                    3
clothes)
Do you have sudden unexplained bursts of pain? (e.g. electric                                              2
shocks, ‘jumping’)
Does the skin temperature in the painful area feel abnormal? (e.g.                                         1
hot, burning)
Exam: Does stroking the affected area of skin with cotton produce                                          5
pain?
Exam: Does a pinprick (23GA) at the affected area feel sharper or                                          3
duller when compared to an area of normal skin?

0 – 12 = likely nociceptive pain, Score > 12 likely neuropathic       Total:
Adapted from: Bennett, M. (2001). Note: this is a smaller sample of the actual scale,
see pp 156-157 in ref listed below.

DN4 Questionnaire

                                       Symptom/Sign                                                  No = 0
                                                                                                     Yes = 1
Does       the   pain                 have      the       following          characteristic?
Burning?
Does       the   pain                 have      the       following          characteristic?
Painful cold?
Does       the   pain                 have      the       following          characteristic?
Electric shocks?
Does      the  area              of     pain       also       have        the      following?
Tingling?
Does      the  area              of     pain       also       have        the      following?
Pins & needles?
Does      the  area              of     pain       also       have        the      following?


                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010       Page 68 of 70
Numbness?
Does     the area     of   pain     also   have     the following?
Itching?
Exam: Decrease in touch sensation (soft brush)?
Exam: Decrease in prick sensation (von Frey hair # 13)?
Exam: Does movement of a soft brush in the area cause or increase
pain?

0 – 3 = likely nociceptive pain  ≥ 4 = likely neuropathic pain       Total:
Adapted from: Bouhassira, D., Attal, N, Alchaar, H., et al. (2005). Note: this is a
smaller sample of the actual questionnaire.

References:

Bennett, M. (2001). The LANSS Pain Scale: The Leeds assessment of neuropathic
symptoms and signs. Pain, 92(1-2); 147 – 157.

Bouhassira, D., Attal, N., Alchaar, H., Boureau, F., Bruxelle, J., Cunin, G, et al. (2005).
Comparison of pain syndromes associated with nervous or somatic lesions and
development of a new neuropathic diagnostic questionnaire (DN4). Pain, 114; 29-36.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 69 of 70
References

ANZCA (2010). Acute Pain guidelines – Scientific Evidence 3rd Edition

Bandolier (2004). NSAIDs, coxibs, smoking and bone. Retrieved 15/04/2009 from
www.ebandolier.com

Blau, LA. & Hoehns, JD. (2003). Analgesic efficacy of calcitonin for vertebral fracture
pain. Ann. Pharmacotherapy 37(4); 564-70

Dworkin, R et al. (2010). Recommendations for the pharmacological management of
neuropathic pain: an overview and literature update. Mayo Clinical Proceedings, 85(3)
(suppl): S3-S14.

Gan, T. et al. (2007). Society for ambulatory anesthesia guidelines for the
management of postoperative nausea and vomiting. Ambulatory Anesthesia 105(6),
1615-1628

Jaeger, H. & Maier, C. (1992). Calcitonin in phantom limb pain: a double-blind study.
Pain 48(1); 21-7

Macintyre, P. & Scott, D. (2009). Managing acute pain safely. Pt 1: opioid-induced
respiratory depression. ANZCA Bulletin, December, 56-59

Treede, RD., Jensen, TS, Campbell, JN. Et al (2008). Neuropathic pain: redefinition
and a grading system for clinical research purposes. Neurology, 70(18); 1630-1635

Visser, E. (2005). A review of calcitonin and its use in the treatment of acute pain.
Acute Pain 7(4); 143-8

Vuolteenaho, K., Moilanen, T., & Moilanen, E. (2008). Non-steroidal anti-inflammatory
drugs, cyclooxygenase-2 and the bone healing process. Basic & Clinical
Pharmacology & Toxicology, 102(1), 10-4.




                                                                              st
WaikatoDHBInpatient Pain Service Pain Management Handbook for adult patients 1 Edition July 2010   Page 70 of 70

								
To top