When Pain Becomes a Disease Than a Symptom!

1. When Pain Becomes a Disease Than a Symptom! Dr R Jayamaha MBBS(Col), MD(SL), FIPP(USA) Consultant Physician Special Interest in Interventional Pain Practice Teaching Hospital, Kandy 08.10.2011

2. History of Pain… Pain; Gods Punishment? • In 1591 Eufan MacAyane of Edinburgh, a young mother, was dragged from her home and taken away. Her pleas for mercy were ignored, and she was thrown into a pit and buried alive.

3. So What Was Her Crime? • She had just given birth to twin sons and during her difficult labor she had asked for pain relief.The church’s teachings of the day regarded the pain of childbirth as a punishment justly inflicted by God!

4. The concept that pain is a visitation from a just God dates at least from the earliest days of ChristianityGenesis 3:16

5. It may be even older….. • Among Egyptian papyri from as much as 4500 years ago there are clear descriptions of what would have been painful surgical procedures. • Although certain herbs were available at that time, that could relieve pain, and were discussed in other papyri, the surgical descriptions themselves make no mention of them.

6. By A.D. 150 to A.D. 200 a few Greek and Roman surgeons were giving herbs that not only relieved pain but also put the patient to sleep, thereby approaching the capabilities of modern anesthetists. • In fact Dioscorides, a Greek army surgeon who was first to use the term Anesthesia

7. But these isolated measures did not spread in Christian Europe • In later centuries Muslim physicians did begin to use various herbs for the relief of pain, soaking a sponge in the appropriate herbs to be inhaled by the patient known as soporific sponges. • They were introduced in Christian Europe by monks between the fourteenth and seventeenth centuries.

8. So…. What is Pain?

9. By Definition Pain is… • “An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage, or both.” International Association for the Study of Pain ( IASP:2001)

10. Pain is what the patient says it is! Never deny patients symptoms for “?FUNCTIONAL ILLNESS”

11. Biological PAIN Social Psychological

12. Classification • Aetiological • Nociceptive pain • Is pain from pain receptor stimulation. It may be somatic pain from activation of receptors in the musculoskeletal system or visceral pain which arises from receptors in the viscera. • Neuropathic pain • Is due to changes in the peripheral or central nervous system. • Idiopathic pain? • Is pain without a known cause, and is not a diagnosis of psychogenic pain. • Chronological • Acute (<3months) • A response to injury or illness • Time limited • Usually responsive to treatment • Inadequate treatment delays recovery • Chronic (>3months) • A state in which pain persists beyond the usual course of an acute disease or healing of an injury, or that may or may not be associated with an acute or chronic pathologic process that causes continuous or intermittent pain over months or years

13. Types of Pain • Acute Pain /Physiological Pain • Nociceptive • Symptom of a disease • Treatment of diseases cures pain & it is self-limiting. • Simple relationship between pain and tissue damage • Proportionate to the clinical finding • Chronic Pain /Pathological Pain • Mostly Neuropathic • A disease itself (a disease of nervous system). • Difficult to treat & sustaining. • Dissociated relationship between pain and tissue damage • Disproportionate to the clinical finding

14. PAIN: an Alarm? True for Acute Pain which is an ALARM.Chronic Pain is a false alarm; it is adisease.

15. Pain Acute Pain (Nociceptive) Chronic Pain (Neuropathic) with ongoing tissue damage (Nociceptive) - Mixed Chronic Pain (Neuropathic) without ongoing tissue damage (Nociceptive)

16. Why Bother So Much? In US…………. • It is estimated that approximately 1/3 of the population suffers from chronic pain and up to 9% of adults suffer from moderate to severe non-cancer related chronic pain (American Pain Society [APS], 2002). • In addition, chronic pain is estimated to affect 15% to 20% of children (Goodman & McGrath, 1991).

17. Pain – 76.2 million people, National Centers for Health Statistics • Diabetes – 20.8 million people (diagnosed and estimated undiagnosed), American Diabetes Association • Coronary Heart Disease (including heart attack and chest pain) andStroke – 18.7 million people, American Heart Association • Cancer – 1.4 million people, American Cancer Society

18. Statistics on Duration Adults 20 years of age and over who reported having pain said that it lasted: • Less than one month – 32% • One to three months – 12% • Three months to one year – 14% • Longer than one year – 42% The suicide rate among pain patients is almost 20 times greater than all other patients because of inadequate relief.

19. Inadequate Pain Treatment Can Lead To… • Lost productivity • Excessive healthcare expenditures • Needless suffering • Domestic and occupational problems • Increased thoughts and risk of suicide • (American Pain Society, 2001: National Conference of State Legislatures, 1999) The economic burden of chronic pain as high as $100 billion annually in US

20. How is pain processed? • Pain results from a series of exchanges among three major components of your nervous system: • Nociceptors / Peripheral nerves (transduction/ transmission) • Spinal cord (+Modulation/neuroplasty) • Brain (Perception/reorganization)

21. Nociceptors • Most concentrated in areas prone to injury Such as fingers and toes. • When nociceptors detect a harmful stimulus They generate a pain message in the form of an electrical impulse along a peripheral nerve to your spinal cord and brain. • They can be epicritic (A-δ/ Fast) or protopathic (C- Slow) pains.

22. Spinal cord • Nerve fibers that transmit pain messages enter the spinal cord in an area called the dorsal horn. • There, they release chemicals (neurotransmitters) that activate other nerve cells in the spinal cord, which process the information and then transmit it up to the brain.

23. Gate-Control Theory: Ronald Melzack (1960s) • Described physiological mechanism by which psychological factors can affect the experience of pain. • Neural gate can open and close thereby modulating pain. • Gate is located in the spinal cord.

24. Brain Brain To brain To brain From pain fibers From pain fibers Transmission Cells Transmission Cells Gating Mechanism Gating Mechanism From other Peripheral fibers From other Peripheral fibers Spinal Cord Spinal Cord Gate-Control Theory Gate is open Gate is closed

25. Three Factors Involved in Opening and Closing the Gate • The amount of activity in the pain fibers. • The amount of activity in other peripheral fibers • Messages that descend from the brain.

27. The Brain • When messages travel up the spinal cord, it arrives at the thalamus • a sorting and switching station deep inside your brain. • The thalamus forwards this message simultaneously to three specialized regions of the brain: • Somatosensory cortex - the physical sensation region • Limbic system - the emotional feeling region • Frontal cortex - the thinking region • The brain then responds to pain by sending down messages which moderate the pain in the spinal cord.

28. What is Sensitization? Sensitization is a phenomenon of inappropriate or disproportionate response to normal stimulus Peripheral Sensitization Central Sensitization

29. Peripheral sensitization • Sensitization of primary afferent terminals. • Active nociceptors become sensitized and sleeping nociceptors awaken. • Damaged axons sprout, forms collaterals. • Ectopic discharges along nerve axon, terminals & at DRG. • SNS fibers invade DRG- CRPS • Phenotypic switch in expression of neuropeptides like Sub P, CGRP.

31. CentralSensitization • Central Re-organisation. • Wind up (summation of signals) • Up-regulation of NMDA receptor • Ectopic activity • Depression inhibitory synapses • Activation of WDR cells.

32. Results of Sensitization • Increased intensity of pain. • Increased area of pain. • Increased duration of pain. • Allodynia • Decreased tolerability to pain. • Development of psychological problems (e.g.. depression due to decreased serotonin level). • Pain become non-responsive to conventional analgesics.

33. Symptoms of chronic pain • Pain in the area of neuro-deficit. • Allodynia, Hyperalgesia • Character of pain: Burning, shooting, electric shock-like, stabbing pain. • Associated symptoms: Numbness, tingling, pruritus, feeling of pin & needles. • SMP: redness, edema, painful joint movements, decreased skin temperature, fall of hairs.

34. Consequences of Unrelieved Pain Cardiovascular • Hypercoagulability • Increased heart rate, blood pressure • Increased cardiac workload • Increased oxygen demand • Increased risk of myocardial infarction

35. Consequences of Unrelieved Pain Respiratory • Diminished respiratory function • Decreased alveolar ventilation • Pneumonia • Atelectasis • Pulmonary embolism • Hypoxia • Slowed wound healing

36. Consequences of Unrelieved PainGastrointestinal • Delayed gastric emptying • Decreased motility • Illus • Anorexia/weight loss

37. Consequences of Unrelieved PainMusculoskeletal • Muscle spasm • Impaired muscle function • Decreased mobility • Decreased ability to ambulate • Diminished short- and long-term recovery & rehab

38. Consequences of Unrelieved PainCognitive • Mental status changes • Confusion • Sleep disturbance • Depression • Behavior disturbances • Anxiety • Anhedonia

39. Consequences of Unrelieved PainPersonal • Inability to perform ADL’s/loss of independence • Impaired relationships with family/friends • Impaired intimacy/sexual activity • Social Isolation • Anger • Loss of self-esteem

40. Pain Assessment • Type of Pain & Aetiology • Severity of Pain • Disability (Physical/ Psychological) • Treatment in Progress

41. Pain Assessment Pain Scales No one will treat hypertension without BP measurement BUT everyone tends to treat without measuring it…..

42. Treatment of ( Mainly Chronic) Pain: MUTIMODAL APPROACH Combination Analgesics Adjuvant Therapy Interventional Pain Management Physical Medicine Psychological Intervention

43. Treatment Strategies • Eliminate barriers to effective pain management • Clarifying controversial issues in pain management • Non-medicinal treatment methods • Appropriate medications for pain relief • Interventional pain management

44. 1.Barriers to Effective Pain Management • Care Providers: Inadequate knowledge re: pain and its management, fear of side effects, fear of regulatory retributions • Patients: Exaggerated fear of addiction, belief that pain is normal/inevitable part of aging • Health Care System: dissuades opioid use, under-utilization of pain specialists due to insufficient knowledge of benefit

45. Treatment Strategies • Eliminate barriers to effective pain management • Clarifying controversial issues in pain management • Appropriate medications for pain relief • Non-medicinal treatment methods • Interventional pain management

46. 2.Controversial Issues in Pain Management • Addiction • Primary, chronic, neurobiologic disease, characterized by a persistent pattern of dysfunctional opioid use with Preoccupation with obtaining opioids despite adequate analgesia • Pseudo-addiction • A set of behaviors a person exhibits to obtain adequate pain relief like becomes focused on obtaining meds, clock watching, may seem to be “drug seeking”, may resort to doctor shopping, deception, to obtain adequate relief. Behaviors resolve when pain treated effectively • Dependence • A state of adaptation manifested by a specific drug class withdrawal syndrome produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist. • Tolerance • A state of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug’s effects over time. Tolerance may develop with opioid side effects (e.g. respiratory depression, drowsiness). Exceeding tolerance can be fatal.

47. “Controlled substances have legitimate clinical usefulness and the prescriber should not hesitate to consider prescribing them when they are indicated for the comfort and well being of the patient.” D.E.A. Physician’s Manual

48. Treatment Strategies • Eliminate barriers to effective pain management • Clarifying controversial issues in pain management • Appropriate Non-Medical & medications for pain relief • Interventional pain management

49. Pain Acute Pain (Nociceptive) Chronic Pain (Neuropathic) with ongoing tissue damage (Nociceptive) - Mixed Chronic Pain (Neuropathic) without ongoing tissue damage (Nociceptive)

50. Aims of Medical Treatment Treatment of Acute Pain Source + Pain Control • Non Pharmacological methods • NSAIDs for a very short period • Paracetamol in adequate doses • Tramadol + Paracetamol in adequate doses • Regional analgesia Treatment of Chronic Pain with Tissue Damage Source + Pain Control + Correcting neuropathy/ central sensitization Treatment of Chronic Pain Without Tissue Damage Correcting neuropathy/ central sensitization • Treatment for peripheral sensitization Na-Channel blocker, Ca-Channel blocker • Treatment for central sensitization NMDA antagonist, Ca-Channel blocker, Opioids, drugs inhibiting Sub P, drugs enhances inhibitory synapses. • Restoration of descending inhibitory pathways Tramadol OR Tricyclics