1. Acute Pain Management Dr Ashish Shetty MBBS, MD(USA), FRCA, FFPMRCA National Hospital for Neurology & Neurosurgery, UCLH Honorary Consultant, Guys & St Thomas Hospital, London

2. Definition 1 Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. IASP 1986

3. Acute Pain 1Cause is known 2Temporary (< 6 weeks) 3Located in area of trauma 4Resolves spontaneously 5 Trauma, Medical, Surgical

4. Clinical characteristics of Acute Pain Sudden, sharp, intense, localised Usually self-limited Consequences Neuro-endocrine, Cardio-Respiratory, Gastrointestinal, Urinary Musculoskeletal Siddall PJ, et al. Neural Blockade in Clinical Anesthesia and Management of Pain; 1998:675–713. Bonica JJ. The Management of Pain. Vol. 1; 1990.

5. 24 yr old Jim Writhing in Pain Fracture of tibia Waiting to go to OR

6. So do post-surgery patients still have pain? Main cause of concern of 57% of patients before surgery 1 Of 3000 surgical and medical patients discharged from UK hospitals: 87% had moderate-to-severe pain in hospital 33% had pain that was present all or most of the time 2 1. Warfield CA and Kahn CH:. Anaesthesiology 1995, 83:1090-1094. 2. Bruster S et al: National survey of hospital patients. British Medical Journal 1994, 309:1542-1546.

7. How effective is postoperative pain therapy? Dolin SJ, Cashman JN, Bland JM. BJA. 2002; 89(3);409-423 Severe painHypoventilation % (95% CI) Hypotension % Mean (95% CI) Intramuscular analgesia 29.1 0.8 (0.2-2.5)3.8 (1.9-7.5) PCA 10.41.2 (0.7-1.9)0.4 (0.1-1.9) Epidural analgesia 7.81.1 (0.6-1.9)5.6 (3.0-10.2) 1973–1999: ‘significant (P<0.000l) reduction in the incidence of moderate-severe pain of 1.9 (1.1–2.7)% per year.’

8. Modulation Transmission of the pain signal to the brain Input Activation of CNS at spinal cord Transmission Activation of the peripheral nervous system Noxious stimulus Nociception- inhibiting neurons Acute pain pathways Peripheral nociceptors Descending modulation Dorsal horn Ascending input Spinothalamic tract Dorsal root ganglion Peripheral nerve Perception Pain

11. I II III IV V VI To dorsal columns C AA AA Primary sensory neurone termination in the dorsal horn

12. Mechanism Peripheral and central sensitisation Wind-up Recruitment of receptive fields Longterm potentiation Immediate early gene expression

13. Importance of Pain management Reduce the Risk of Adverse Outcomes Maintain the Patient’s Functional Ability, as well as Psychological Well-being Enhance the Quality of Life Shortened Hospital Stay and Reduced Cost Patient comfort and satisfaction 1. Eisenach JC, et al. Anesthesiology. 1988;68:444–448. 2. Harrison DM, et al. Anesthesiology. 1988;68:454–457. 3. Miaskowski C, et al. Pain. 1999;80:23–29. 4. Finley RJ, et al. Pain. 1984;2:S397.

14. Pain Assessment Tools

15. In Adults: Self Report Measurement Scales, such as Numerical Scales In Pediatric Patients: Physiologic and Behavioral Indicators of Pain ( Infants, Toddlers, Nonverbal or Critically Ill Children) Face Scale (Age 3-10 yrs) Visual Analogue Scales (Age 10-18)

18. Management of Acute Pain Pharmacologic Interventional

19. Pharmacologic Management Alter Nerve Conduction (Local Anesthetics Modify Transmission in the Dorsal Horn (Opioids, Antidepressants) CNS modulation

20. Routes of Administration PO PR IV IM Transdermal Transmucosal Epidural Intrathecal

21. Principles Of Pain Management

22. WHO

23. Analgesic ladder

24. Acute Pain Analgesic Staircase Stage 1:Immediately post-operative Strong opioid eg morphine or epidural +/- non-opioid analgesic Stage 2: Oral opioid for moderate to strong pain +/- non-opioid analgesic( NSAID) Stage 3: Prior to discharge Non- opioid analgesic

25. What Endpoint Should Be Achieved? Patient awake and not nauseated Ability to mobilise, cooperate with physiotherapy, eg coughing, deep breathing VAS of below 30mm on a scale of 0-100mm seen as adequate

26. New developments: Delivery technology

27. Non-opioid Analgesics Paracetamol: Acetaminophen centrally acting 1g 6h or 15- 20mg/kg for children Diclofenac sodium: 50mg TDS orally NSAIDs: Analgesic, antipyretic,antiinflammato ry Opioid sparing SE: Prostaglandin and prostacyclin effect Ibuprofen, diclofenac, naproxen, piroxicam COX 1 and COX 2

28. Non-Opioid Analgesics Acetaminophen NSAIDs ( Ibuprofen, Diclofenac) COX-2 inhibitors Lidocaine Patch

29. NSAIDs Relieve of Mild to Moderate Pain Complication: GI Discomfort GI Bleeding (Inhibition of COX-1) Nephrotoxicity Inhibition of Platelet Aggregation Osteogenesis

30. IV NSAID: Ketorolac Potent Analgesic Parenteral (IV or IM) 15-30 mg Q 6hr Patients Older than 16 yrs Should not Exceed 5 days

32. Cox-2 Inhibitors DrugDose Celecoxib (Celebrex) 100-200mg PO Bid Rofecoxib (Vioxx) Valdecoxib (Bextra) 10-20mg PO Qd Parecoxib 20-40mg IM 20-100mg IV

33. Compound Analgesics Co-Proxamol: Paracetamol 325mg, Dextropropoxyphene 32.5mg Co-Dydramol: Paracetamol 500mg, Dihydrocodeine 10mg Co-Codamol: Paracetamol 500mg, Codeine phosphate 8mg Aspav:Aspirin 500mg and opium alkaloids

34. Weak opioids Dihydrocodeine 30mg 4 hrly po Tramadol weak iv,po agonist 50- 100mg Buprenorphine 200-400mcg sl 4-6h Codeine phosphate 30-60mg 4h Strong opioids Morphine Fentanyl Diamorphine Pethidine: max 1.2g daily

35. Opioid Analgesics Bind to Opioid Receptors Morphine, Fentanyl, Codeine, Oxycodone, Hydrocodone, Tramadol Multimodal analgesia enhance Opioid Analgesic Effect

36. Opioid Analgesics Equianalgesic Conversion Charts are used when Converting form one Opioid to Another, or Converting from Parenteral to Oral Form Respiratory Monitors may be Used Depending on the Patients Age, Co-existing Medical Problems, or Route of Opioid Administered

37. Conversions : Morphine Oral Parenteral Epidural Intrathecal 300100 10 1

38. Patient controlled analgesia

39. Patient Controlled Analgesia Small Doses of Analgesic Drug (Usually Opioids), are Administered (IV) by Patient Allows Basal Infusion and Demand Boluses Over Dosage is Avoided by Limiting the Amount and Number of Boluses in a Set Period of Time

40. Dose Regimens for PCA Drug Bolus Dose (mg) Lock-Out (Minutes) Morphine15 Fentanyl0.01-0.023

41. Patient Controlled Analgesia Advantages Safe, effective, good analgesia, reduces delay, saves nursing time, high patient satisfaction, few complications Disadvantages Respiratory depression, nausea and vomiting, programming errors, costs

42. PCA

43. OpioidsDrug PO mg IV mg Starting Oral Dose mg Comments Morphine301015-30 MS Contin, Release 8-12 hrs MSIR for BTP Methadone2010 5-10 Qd Long Half-Life, 24-36 hrs Accumulates on Days 2-3 Fentanyl 0.02- 0.05 Fentanyl Patch, 12 hrs Delay Onset and Offset

44. Opioids Drug PO mg CommentsPrecautions Codeine30-60 Combined With Nonnarcotic Analgesics Maximal Dose for Acetaminophen 4gm/d Oxycodone5-10 Oxycodone 10-30mg Q 4h Oxycontin 10mg Q 12h Acetaminophen or Aspirin toxicity Tramodol 50-100 Q4- 6hr Central Acting, Affinity for Mu Receptors Maximal Dose 400 mg/d

45. Multimodal Analgesia Reduced doses of each analgesic Improved pain relief Synergistic / additive effects Reduces severity of side effects of each drug Kehlet H, Dahl JB. Anesth Analg. 1993;77:1048-1056. Playford RJ, et al. Digestion. 1991;49:198-203. Morphine NSAIDs, paracetamol, nerve blocks Potentiation

46. Multimodal Therapy: Diclofenac  Paracetamol  Codeine Breivik et al, Clin Pharmacol Ther 1999;66:625-635 D = 100 mg diclofenac alone; P = 1 g paracetamol alone; P+C = 1 g paracetamol plus 60 mg codeine; D+P = single oral dose 100-mg enteric-coated diclofenac with 1 g paracetamol; D+P+C = 100-mg enteric-coated diclofenac with 1 g paracetamol plus 60 mg codeine Mean (SE) total pain relief for the 0.5- to 8-hour observation period 0 10 20 30 40 50 60 DPP+CD+PD+P+C ** *** * *p= 0.044; **p= 0.029; *** p= 0.002

47. Adjuvant analgesics for opioid sparing strategies Established NSAIDs and coxibs (safety and tolerability issues) Paracetamol Local anaesthetic techniques Recent additional choices Gabapentin Low dose ketamine Dexamethasone

48. Mr Jones will undergo a thoracotomy. What would be your analgesia of choice?

49. Interventional Management Epidural Analgesia (Continuous Lumbar or Thoracic Epidural Catheter Placement, PCEA) Spinal Analgesia Peripheral Nerve Block ( Single Shot or Continuous)

50. Epidural Space Surrounds the Dural Sac Anteriorly: Post. Long. Ligament Posteriorly: Ligamentum Flavum Laterally: Pedicles and Intervertebral Foramina

51. Anatomy of Epidural Space AP Dimension of the Epidural Space is Largest in the Lumbar Region, 5-6 mm In Thoracic Region the AP Dimension Decreases but the Space is More Continuous

52. MIDLINE SAGITTAL VIEW OF THE LUMBAR SPINE

54. Epidural Anesthesia Acts the emerging nerve roots from Spinal Cord “dermatomal “band” of Anesthesia Level of Anesthesia Depends on : Volume of the Drug Level of Injection

55. Epidural Anesthesia Lumbar Epidural: Lower Extremity, Pelvic, and Lower Abdominal Procedures Thoracic Epidural: Upper Abdomen and Thoracic Procedures Caudal Injection: More Commonly Used for Pediatric Patients (Genitourinary and Lower Abdominal Procedures)

56. Advantages Superior Pain Relief with Lower Incidence of DVT and Pulmonary Emboli Decrease Blood Loss Intraoperatively More Rapid Recovery of Bowel Function Earlier Ambulation Better PFT Suppression of Neuroendocrine Stress Res Grass JA. The Role of Epidural Anesthesia and Analgesia in Postoperative Outcome. Anesthesiol Clin North America 01-JUN-2000; 18(2): 407-28

57. Contraindications Absolute  Patient Refusal  Coagulopathy  Increased ICP  Skin Infection Relative  Uncooperative Patient  Pre-existing Neurologic Disorder  Anatomical Abnormalities

58. Drugs used in Epidural Local Anesthetics Lidocaine: 1-2%, 45-90 min. Bupivacaine: 0.25-0.5%, 90-120 min. Opioids : Diamorphine, Fentanyl Others :Clonidine, Ketamine etc.

59. Opioids in Epidural Space DrugDosage Onset (min) Duration (hrs) Morphine 2-3 mg 30-906-24 Fentanyl 50-100 mcg 5-152-4

60. Diamorphine Advantages  Prolonged Single Dose Analgesia  Thoracic Analgesia with Lumbar Administration  Minimal Dose Compared with IV Administration Disadvantages  Delayed Onset of Analgesia  Unpredictable Duration  Delayed Respiratory Depression

61. Local Anaesthetic Techniques Local anaesthetics are either esters or amides Influence action potential along the nerve Local infiltration Nerve block/ Plexus block Caudal/ epidural/spinal analgesia

62. Epidural analgesia

63. Promises of epidural analgesia Mortality Morbidity Cardiovascular Respiratory Coagulation Major infections Quality of pain relief Hospital costs

65. Problems Dural puncture Epidural haematoma Epidural abscess Failure of technique Training Resource restraint

66. Epidural complications Failure of Block (Patchy or Unilateral Block) Injury to Nerve Infection Epidural Hematoma or Abscess Dural Puncture (Total Spinal or PDPH)

67. Epidural complications - Hypotension Secondary to Sympathetic Blockade - Intravascular Injection (Local Anesthetic Toxicity) - Respiratory Depression - Sedation - Bladder Distention - Difficulty in Ambulation

68. Spinal Anesthesia Spinal Anesthesia : injecting small amount of local anesthetic in the CSF Results in Rapid Onset of Block Rapid onset and requiring low dose of drugs

69. Spinal Anesthesia CSE, Used in Labor Preservative Free Morphine -Provides Pain Relief for Abdominal, Pelvic, or Lower Extrimity Surgeries Complications Similar to Epidural Technique Except for Higher Risk of PDPH

72. Caudal Block Single Injection or Continuous Infusion through a Catheter Excellent Intraoperative and Postoperative Pain Control Easier to Perform in Children Analgesia that Last About 12 hrs if Bupivacaine Used Performed Following Induction of General Anesthesia

73. Indications for Caudal Block Surgeries in Sacral Segments, (Circumcision and other Urologic Surgeries, Rectal Dilation) Combined with Light General Anesthesia Provides Adequate Intraoperative Analgesia

74. Complications of Caudal Block Infection Dural Puncture and Spinal Anesthesia Intravascular Injection of Local Anesthetics

75. Peripheral Nerve Block Anesthetising the Nerve that is Innervating Surgical or Painful Area Single Shot or Continuous Infusion through Catheter Upper Extrimity: Brachial Plexus, Median, Ulnar or Radial Nerve

76. Peripheral Nerve Block Lower Extrimity: Sciatic, Femoral, Posterior Tibial, Sural, Saphenous, Deep and Superficial Peroneal Nerve Intercostal Nerve Block Surgical Wound Infiltration of Local Anesthetic

78. Julie 4yrs old is scheduled for a fixation of her fractured femur.

79. Pain Management in Children Consider Physiologic and Anatomic Differences Assessment and Communication barriers Pain and Anxiety Associated with Minor Procedures or Unfamiliar Situations

80. Children Opioid sensitive PCA/NCA Simple analgesics very useful Regional analgesia

81. The Elderly patient Slow circulation time Associated diseases Respiratory recovery important Early mobilisation

82. Elderly Patient Population Older than 65 yrs of Age is Growing Age Related Physiologic Changes (Decreased Muscle Strength): Decreased Cough Decreased Mental Status (Dementia): Decreased Narcotic Dose

84. Mr Jones Your consultant has decided to discontinue the epidural analgesia. What are the appropriate next steps?

85. Step down analgesia Aim: To discharge the patient on non-opioid analgesic medication, often simple analgesics such as paracetamol 1g QDS If the patient is discharged on strong opioids the GP is informed and a reduction plan advised.

86. Chronic pain after surgery: Phantom limb pain

87. Summary Every patient has got individual needs. Pain is best treated in a multimodal fashion Balanced analgesia with opioids, reduced peripheral stimulus (NSAID’s), interrupted pain pathways, eg nerve block and alteration of emotional and behavioural response Careful monitoring of cardiovascular and respiratory functions in the postoperative patient Evidence that good pain relief will reduce the incidence of ongoing pain

88. Multidisciplinary Approach Acute Pain Team Pharmacist Nurse Anaesthetist Physiotherapist Psychologist Surgeon

89. My Philosophy No Pain….

90. My Philosophy No Pain….no Pain Thank you