This document was developed by the Surgical and Emergency Medicine Services Unit, Medical Development Section of the Medical Development Division, Ministry of Health Malaysia and the Editorial Team for the Pain Management Handbook Published in October 2013 A catalogue record of this document is available from the library and Resource Unit of the Institute of Medical Research, Ministry of Health; MOH/P/PAK/257.12 (HB), MOH Portal: www.moh.gov.my And also available from the National Library of Malaysia; ISBN 978-967-0399-38-6 All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means or stored in a database or retrieval system without prior written permission from the Director of Medical Development Division, Ministry of Health Malaysia (MOH). CONTENTS Editorial Team/Contributors viii Foreword ix Preface x CHAPTER 1: PRINCIPLES OF PAIN MANAGEMENT Objectives of Pain Management Services Principles of Pain Management CHAPTER 2: PHYSIOLOGY OF PAIN Definition of pain Pain pathway Problems of postoperative pain Spectrum of pain CHAPTER 3: PHARMACOLOGY OF ANALGESIC DRUGS Opioid Analgesics Mechanism of Action Pharmacokinetics of Opioids Pharmacodynamics of Opioids Indications Precautions Side Effects Dosages Important Points about Commonly Used Opioids Nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 selective inhibitors Mechanism of action Indications Contraindications Side effects Dosages Local anaesthetics Mechanism of action Pharmacokinetics Indications Contraindications Toxicity of Local Anaesthetics Other analgesic drugs Paracetamol Ketamine Methoxyflurane Nitrous oxide Adjuvants Pharmacology of analgesics in special groups Renal disease Liver Disease Elderly Patients CHAPTER 4: ASSESSMENT AND MONITORING Assessment of pain Taking a Brief Pain History Pain assessment tools Pain as the 5th vital sign Monitoring of patients on APS CHAPTER 5: MANAGEMENT OF ACUTE PAIN Acute Pain Service (APS) Setting up an APS Pain management techniques Factors to consider when choosing a technique Non-pharmacological approaches Pharmacological approaches Multi-modal Analgesia Patient controlled analgesia (PCA) Indications Contraindications Advantages Disadvantages Features of PCA and programming modes Common problems with PCA and what to do When to stop PCA Analgesia after PCA is stopped Adverse effects of PCA opioids Complications related to PCA Responsibilities of doctors and nurses Central neuraxial block Anatomy relevant to epidural analgesia Definitions Indications Contraindications Advantages Disadvantages Drugs used Mechanism of action of drugs used Epidural analgesia using mixtures of LA and opioids (“cocktail”) Patient-Controlled Epidural Analgesia (PCEA) Epidural analgesia using opioids alone Intrathecal Opioid Analgesia Subcutaneous morphine Peripheral nerve blocks Types of blocks Local anaesthetic selection Catheter placement Contraindications Complications Transversus Abdominis Plane (TAP) Block Pain management in non-APS patient CHAPTER 6: COMPLICATIONS AND MANAGEMENT Complications related to drugs Complications related to technique Management of complications Nausea and vomiting Excessive drowsiness Respiratory Depression Pruritus Ileus / Constipation Hypotension Urinary Retention Motor Blockade Post Dural Puncture Headache Neurological complications CHAPTER 7: ACUTE NEUROPATHIC PAIN Characteristic of neuropathic pain Causes of acute neuropathic pain Recommended treatment CHAPTER 8: ACUTE PAIN MANAGEMENT IN OPIOID TOLERANT PATIENT Identification of opioid tolerant patient Acute pain management in opioid tolerant patient CHAPTER 9: ANALGESIA FOR PROCEDURAL PAIN Management of procedural pain Non-pharmacological Pharmacological Oral route Subcutaneous route IV route Topical Inhalational CHAPTER 10: PAEDIATRIC ACUTE PAIN MANAGEMENT Principles of pain management in children Pain assessment in children Methods of pain management in children Non-pharmacological methods Pharmacological methods Management of procedural pain Guidelines for pain management in children with burns Management of post-operative pain Paracetamol NSAIDs Tramadol Intravenous opioid infusion How to prescribe an IV opioid infusion Standard orders for opioid infusion Management of major complications Patient Controlled Analgesia (PCA) Indications Contraindications How to prescribe PCA Preparation of solution for PCA infusion Standard orders for ward nurses and doctors Management of major complications Local and Regional Analgesia Instillation LA Wound infiltration Peripheral nerve blocks Epidural Infusion How to prescribe an epidural infusion Standard orders Management of major complications Pain Scoring Systems for Paediatric Patients FLACC Score Faces Scale Numerical Scale Grading Severity for all three Pain Scales Sedation Score Vomiting Score Bromage Score CHAPTER 11: OBSTETRIC ANALGESIA AND ANAESTHESIA SERVICE (OAS) Principles of pain relief in the obstetric patient Mechanisms of pain transmission in the parturient Factors that may influence the pain of childbirth Physiological changes in labour Guidelines for regional techniques for labour analgesia Prior to performance of regional technique Criteria for initiation of epidural analgesia Monitoring Techniques Protocols for management of labour pain Lumbar Epidural Combined Spinal-Epidural PCA Fentanyl Management of complications of regional analgesia Hypotension Unintentional dural puncture Post Dural Puncture Headache (PDPH) Unintentional intravascular injection of Local Anaesthetic Unexpected high block Inadequate analgesia Pruritus Post-operative analgesia Intrathecal Morphine Epidural Morphine Epidural Cocktail (LA + fentanyl) Patient Controlled Analgesia (PCA) Supplemental analgesia Prevention of post-LSCS nausea and vomiting (PONV) CHAPTER 12: MANAGEMENT OF PAIN IN ADULT DAY SURGERY PATIENTS General Principles Techniques for Intraoperative analgesia Regional Analgesia Parenteral and oral analgesics Pain management in the Post-Anaesthesia Care Unit (PACU) Pain management in the Day Surgery Unit before discharge Non-pharmacological methods of pain management Analgesic therapy on discharge Analgesia according to the anticipated severity of pain Special considerations CHAPTER 13: CHRONIC NON-CANCER PAIN Differences between Acute and Chronic Pain Making a diagnosis of chronic pain Principles of management of chronic non-cancer pain Management of chronic pain patients in the Pain Clinic Appendices Appendix 1: Instructions for Medical Officers and APS nurse Appendix2: APS Nursing Observation Chart Appendix 3: Acute Pain Audit Form Appendix 4: Guidelines for Use of Oxynorm® in Patient Weaned off PCA Morphine Appendix 5: IV Morphine Pain Protocol Appendix 6: Analgesic Ladder for Acute Pain Management Appendix 7: Recommendations on Neural Blockade and Anticoagulant Appendix 8: Management of Severe Local Anaesthetic Toxicity Appendix 9: Drug Formulary List of Figures Figure 2.1: Pain Pathway Figure 2.2: Spectrum of Pain Figure 3.1: Plasma concentration for Intermittent IM/SC Injection Figure 3.2: Plasma concentration for Intermittent IV Injection Figure 3.3: Plasma concentration for Continuous IV Infusion Figure 3.4: Plasma concentration for Continuous IV Infusion plus Loading Dose Figure 3.5: Plasma concentration for IV Patient Controlled Anaesthesia Figure 3.6: Cyclo-oxygenase Pathways Figure 3.7: Chemical Structure of Local Anaesthetics (LAs) Figure 3.8: The relationship between Lignocaine Plasma Concentration and Pharmacological Effects Figure 5.1: Anatomy of the Vertebra column Figure 5.2: Cutaneous innervations of upper limb Figure 5.3: Cutaneeous innervations of lower limb Figure 5.4: Surface Landmark of Triangle of Petit Figure 10.1: WHO analgesic ladder Figure 11.1: Pain Pathways in a parturient Figure 11.2: Dermatomes of the lower abdomen, perineal area, hips and thighs List of Tables Table 3.1: Analgesic Medications for Acute Pain Management Table 3.2: Features of Opioid Receptors Table 3.3: Pharmacokinetic & Pharmacodynamic Profile of Opioids Table 3.4: Commonly Available Local Anaesthetics (LAs) Table 3.5: Use of IV Ketamine as Analgesic Adjuvant to General Anaesthesia and PCA Table 3.6: Commonly Available Adjuvants Table 3.7: Recommended Use of Selected Opioids in Patient with Renal dysfunction & Dialysis Patients Table 3.8: Recommended Dosage Adjustments for Selected Opioids in renal insufficiency Table 3.9: Recommended Use of opioids in Hepatic Dysfunction Table 5.1: Comparison of Effects between Opioids and Local Anaesthetics Table 5.2: Recommended Epidural Bolus dosing Table 5.3: Epidural Opioids: Dosage, Onset and Duration of Action Table 5.4: Pharmacological Properties of Common Opioids Used for Intrathecal Analgesia Table 5.5: Optimal Intrathecal Opioids Dose for Specific Surgical Procedures Table 5.6: Incidence, Proposed Mechanism and Treatment for Intrathecal Opioids related Side Effects Table 5.7: Upper Extremity Blocks and Indications Table 5.8: Lower Extremity Blocks and Indications Table 5.9: Truncal Blocks and Indications Table 5.10: LA Selection & Concentration Table 5.11: Concentration for intermittent IV injection Dose of LA for continuous infusion with or without PCA bolus Table 8.1: Terminology Table 8.2: Signs and Symptoms of Opioids Withdrawal Table 8.3: Comparison of oral Morphine and Transdermal Patch Dosage Table 8.4: Suggested Dose Conversion Ratio Table 8.5: Recommendation and Equianalgesia Dose Conversion Ratios for Peri-operative Pain Management Table 10.1: Suggested Ketamine Dose for infusion Table 10.2: Guildeline