Pain Management

definition of pain - classification - categories and different clinical types of pain - assessment of pain and how to manage using pharmacological and non-pharmacological intervention

1. PAIN MANAGEMENT Dr. Sameh Ahmad Muhamad abdelghany Lecturer Of Clinical Pharmacology Mansura Faculty of medicine

2. 2 CONTENTS 1 4 5 3 2 PAIN ASSESSMENT TREATMENT INTRODUCTION CLASSIFICATION TYPES

3. 3 1 INTRODUCTION

4. 4 Introduction Definition : An unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain may not be directly proportional to amount of tissue injury. Highly subjective, leading to undertreatment

5. 5 In cancer, the prevalence of pain in advanced disease is 70-90%. " In HIV disease, pain prevalence is about 50%. " Other illnesses may have significant pain but no clear data.

6. 6 2 CLASSIFICATION

7. 7 Classification Acute Chronic : Non malignant Malignant

8. 8 Injury, trauma, spasm or disease to skin, muscle, somatic structures or viscera; Perceived and communicated via peripheral mechanisms (pathways) Usually associated with autonomic response as well (tachycardia,­ blood pressure, diaphoresis, pallor, mydriasis (pupil dilation). Acute Pain

9. 9 Usually subsides quickly as pain producing stimuli decreases Associated with anxiety-(decreases rapidly) Can be understood or rationalized as part of the healing process. Cont.

10. 10 Non-malignant Pain persists beyond the precipitating injury Rarely accompanied by autonomic symptoms Sufferers often fail to demonstrate objective evidence of underlying pathology. Characterized by location-visceral, myofacial , or neurologic causes. II. Chronic Pain

11. 11 Malignant Has characteristics of chronic pain as well as symptoms of acute pain (breakthrough pain). Has a definable cause, e.g. tumor recurrence In treatment, narcotic habituation is generally not a concern. II. Chronic Pain

12. 12 3 TYPES OF PAIN

13. 13 Types of Pain Somatic Visceral Bone Neuropathic Emotional/Spiritual

14. 14 I- Somatic Pain Aching, often constant May be dull or sharp Often worse with movement Well localized Skin, Muscle, Joints, superficial or deep. Eg : Bone & soft tissue chest wall

15. 15 II- Visceral Pain Constant or crampy Aching, burning Poorly localized Referred Organs of Thorax & Abdominal Cavity. Usually as a result of stretching, infiltration and compression Eg : Liver capsule distension Bowel obstruction

16. 16 Both Somatic & Visceral pain travel along the same pathways. Pain stimuli arising from the viscera is perceived as somatic in origin. This can be confused by the brain and is often described as referred pain .

17. 17 III- Bone Pain Poorly localized, aching, deep, burning. Common with malignancy of Breast, Lung, Prostate, Bladder, Cervical, Renal, Colon, Stomach and Esophagus Can lead to pathological fractures. Vertebral Metastases can lead to cord compression.

18. 18 IV- Neuropathic Pain Caused by disturbance of function or pathological changes in a nerve. May arise from a lesion or trauma, infection, compression or tumour invasion. Described as burning, shooting, tingling. Does not respond well to standard analgesics.

19. 19 Categories of Pain Classified by inferred pathophysiology: Nociceptive pain (stimuli from somatic and visceral structures) Neuropathic pain (stimuli abnormally processed by the nervous system)

20. 20 Nociceptive: Caused by invasion &/or destruction &/or pressure on superficial somatic structures like skin, deeper skeletal structures such as bone & muscle and visceral structures and organs. Types: superficial somatic, deep somatic, & visceral.

21. 21 Neuropathic: Caused by pressure on &/or destruction of peripheral, autonomic or central nervous system structures. Radiation of pain along dermatomal or peripheral nerve distributions. Often described as burning and/or deep aching & associated with dysesthesia or lancinating pain.

22. 22 Effects of pain Sympathetic responses Pallor Increased blood pressure Increased pulse Increased respiration Skeletal muscle tension Diaphoresis

23. 23 Effects of pain Parasympathetic responses Decreased blood pressure Decreased pulse Nausea & vomiting Weakness Pallor Loss of consciousness

24. 24 4 Pain Assessment

25. 25 Pain History The site of pain Type of pain Exacerbating & Relieving factors How frequently Impact on daily life

26. 26 Pain History Other important additional questions to be asked. What is the response to past and current analgesic therapy? Any kind of diary or record about the pain? Fears they have about analgesics?

27. 27 PAIN ASSESSMENT Tools Verbal Analogue Scales . Visual Analogue Scales . The Faces Scale

28. 28 Factors to consider in choosing a pain scale Age of patient Physical condition Level of consciousness Mental status Ability to c ommunicate

29. 29 Numeric Pain Rating Scale Ask the patient to rate their pain intensity on a scale of 0 (no pain) to 10 (the worst pain imaginable). Some patients are unable to do this with only verbal instructions, but may be able to look at a number scale and point to the number that describes the intensity of pain.

30. 30 Numeric Pain Rating Scale

31. 31 Wong-Baker FACES Pain Rating Scale Can be used with young children (sometimes as young as 3 years of age) Works well for many older children and adults as well as for those who speak a different language Explain that each face represents a person who may have no pain, some pain, or as much pain as imaginable. Point to the appropriate face and say the appropriate description. e.g. “This face hurts just a little bit”

32. 32 Wong-Baker FACES Pain Rating Scale Ask the patient to choose the face that best matches how she or he feels or how much they hurt.

33. 33 Color Pain Rating Scale Ask the patient to point to the area on the scale that shows their level of pain from white (no pain) to dark red (worst possible pain). Obtain a number corresponding to the area where the patient points.

34. 34 Severity Assessment McGill Pain Questionnaire Scale from 0 to 5 From None to Severe Pain for children or adults who understand numerical relationships.

35. 35 PAIN ASSESSMENT Tools

36. 36 5 Pain Treatment

37. 37 Goals of Pain Management Therapy Decreased pain Decreased healthcare utilization Decreased “shopping” for care Decreased emergency room visits Improved functional status Increased ability to perform activities of daily living Return to employment

38. 38 Management Non- Pharamcological treatment Pharmacological treatment: Analgesics Adjuvants Others

39. 39 Non-pharmacological interventions Exercise Weight reduction Counseling Smoking cessation Massage ,Relaxation therapy Heat & cold applications

40. 40 Non-pharmacological interventions

41. 41 Analgesics Non-opioid e.g. aspirin,paracetamol Opioids e.g. codeine, morphine Adjuvant e.g. muscle relaxant, antidepressant, anti-epileptic

42. 42 Choosing the Appropriate Analgesic Match the severity of pain to the strength of the analgesic i.e. strong analgesics for severe pain. The WHO has developed 3-step model to guide analgesic choice depending on the severity of the patient’s pain.

43. 43 WHO Pain Management Ladder Step I: NSAIDS ± adjuvants Step II: NSAID + Mild opioids ± adjuvant Step III: Strong opioids + NSAIDS ± adjuvants

44. 44 Analgesics(Non-opioids) There are three types of non-opioid analgesics: Salicylates Non-Steroidal Anti-Inflammatory Drugs Acetaminophen

45. 45 Analgesics(Non-opioids) Used in full doses for the most part. All have a ceiling effect to their analgesia ( a maximum dose past which no further analgesia can be expected). COX-2 inhibitors may be associated with fewer side-effects

46. 46 Analgesics(Non-opioids) Use cytoprotection with NSAIDs only in patients who have symptoms suggestive of GI distress or who are at high risk of ulcer formation. For cytoprotection use sulcrafate or misoprostol.

47. 47 Analgesics(Weak Opioids) Useful drugs: Codeine & codeine combination products Oxycodone combination products. DO NOT USE : Dextropropoxyphene

48. 48 Analgesics(Strong Opioids) Useful drugs: Morphine , hydromorphone, fentanyl, oxycodone , methadone. DO NOT USE : Meperidine , anileridine , pentazocine

49. 49 Opioid Dosing Opioid analgesia is most effective when titrated to effect. Effective doses are highly variable between patients. “Standard” doses may be insufficient. When used properly for analgesia addiction occurs in less than 1% of patients.

50. 50 Opioid Side Effects Constipation : need proactive laxative use Nausea/vomiting: consider treating with dopamine antagonists and/or prokinetics (metoclopramide, domperidone, prochlorperazine, haloperidol) Urinary retention

51. 51 Cont. Itch/rash worse in children; may need low-dose naloxone infusion. May try antihistamines, however not great success Dry mouth Respiratory depression uncommon when titrated in response to symptom Neurotoxicity: delirium, myoclonus seizures. Drug interactions

52. 52 Adjuvant analgesics ( coanalgesics ) Are medications that when added to primary analgesics, further improve pain control. may themselves also be primary analgesics (e.g. tricyclic antidepressant medications for postherpetic neuralgia). They can be added into the pain management plan at any step in the WHO ladder.

53. 53 Adjuvants for Neuropathic Pain When pain is neuropathic there is good evidence for treating with adjuvant medication rapidly. Always remember the potential of using radiotherapy, chemotherapy and surgery as adjuvant modalities with neuropathic pain but they should not replace drug adjuvants completely. An adequate trial of 2-4 weeks at full dosage should be tried for each drug

54. 54 Adjuvants for Neuropathic Pain Cyclic Antidepressants : Amitriptyline - desipramine - nortriptyline –maprotiline Anticonvulsants: carbamazepine - valproic acid - gabapentin Local Anesthetics: mexiletine - lidocaine

55. 55 Other modalities Nerve blocks, epidural blocks and ablative neurosurgical procedures may be effective in pain management. Such procedures may be associated with return of pain after a number of months so that timing of procedures may be important.

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