Presentation on theme: "When Pain Becomes a Disease Than a Symptom!"— Presentation transcript:
1 When Pain Becomes a Disease Than a Symptom! Dr R Jayamaha MBBS(Col), MD(SL), FIPP(USA)Consultant PhysicianSpecial Interest in Interventional Pain PracticeTeaching Hospital, Kandy
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 Christianity Genesis 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.
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”
12 Classification Acute (<3months) Aetiological Chronological Nociceptive painIs 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 painIs 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.ChronologicalAcute (<3months)A response to injury or illnessTime limitedUsually responsive to treatmentInadequate treatment delays recoveryChronic (>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 diseaseTreatment of diseases cures pain & it is self-limiting.Simple relationship between pain and tissue damageProportionate to the clinical findingChronic Pain /Pathological PainMostly NeuropathicA disease itself (a disease of nervous system).Difficult to treat & sustaining.Dissociated relationship between pain and tissue damageDisproportionate to the clinical finding
14 PAIN: an Alarm?True for Acute Pain which is an ALARM. Chronic Pain is a false alarm; it is a disease.
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 AssociationCoronary Heart Disease (including heart attack and chest pain) and Stroke – 18.7 million people, American Heart AssociationCancer – 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.As many as 75% of even cancer pain patients receive grossly inadequate pain relief.Because of this, the suicide rate among pain patients is almost 20 times that of all other patients.
19 Inadequate Pain Treatment Can Lead To… Lost productivityExcessive healthcare expendituresNeedless sufferingDomestic and occupational problemsIncreased 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 USThese factors have driven estimates of the economic burden of chronic pain as high as $100 billion annually
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 stimulusThey 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 Gate-Control Theory From pain fibers other Peripheral To brain From Spinal CordGatingMechanismTransmissionCellsFrompainfibersotherPeripheralTobrainBrainSpinal CordGatingMechanismTransmissionCellsFrompainfibersotherPeripheralTobrainPain signals arrive from the pain fibers (A-delta and C) at the spinal cord, along with signals from other peripheral fibers (A-beta) and the brain. The solid arrows depict stimulation conditions that tend to open the gate and send pain signals through. The dotted arrows indicate inhibition conditions. Pain signals enter the spinal cord and pass through a gating mechanism before activating transmission cells, which send impulses to the brain (from text by Sarafino EP. Health Psychology, Biopsychosocical Interactions, Third Edition. John Wiley & Sons, Inc. New York: 1998.)Gate is openGate 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 fibersMessages that descend from the brain.
27 The BrainWhen messages travel up the spinal cord, it arrives at the thalamusa 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 regionLimbic system - the emotional feeling regionFrontal cortex - the thinking regionThe 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 stimulusPeripheral SensitizationCentral 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- CRPSPhenotypic switch in expression of neuropeptides like Sub P, CGRP.
31 Central Sensitization Central Re-organisation.Wind up (summation of signals)Up-regulation of NMDA receptorEctopic activityDepression inhibitory synapsesActivation of WDR cells.
32 Results of Sensitization PainSensitizationDecreased toleranceIncreased intensity of pain.Increased area of pain.Increased duration of pain.AllodyniaDecreased 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, HyperalgesiaCharacter 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 HypercoagulabilityIncreased heart rate, blood pressureIncreased cardiac workloadIncreased oxygen demandIncreased risk of myocardial infarction
36 Consequences of Unrelieved Pain Gastrointestinal Delayed gastric emptyingDecreased motilityIllusAnorexia/weight loss
37 Consequences of Unrelieved Pain Musculoskeletal Muscle spasmImpaired muscle functionDecreased mobilityDecreased ability to ambulateDiminished short- and long-term recovery & rehab
38 Consequences of Unrelieved Pain Cognitive Mental status changesConfusionSleep disturbanceDepressionBehavior disturbancesAnxietyAnhedonia
39 Consequences of Unrelieved Pain Personal Inability to perform ADL’s/loss of independenceImpaired relationships with family/friendsImpaired intimacy/sexual activitySocial IsolationAngerLoss 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…..
43 Treatment Strategies Eliminate barriers to effective pain management Clarifying controversial issues in pain managementNon-medicinal treatment methodsAppropriate medications for pain reliefInterventional 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 retributionsPatients: Exaggerated fear of addiction, belief that pain is normal/inevitable part of agingHealth 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 managementAppropriate medications for pain reliefNon-medicinal treatment methodsInterventional pain management
46 2.Controversial Issues in Pain Management AddictionPrimary, chronic, neurobiologic disease, characterized by a persistent pattern of dysfunctional opioid use with Preoccupation with obtaining opioids despite adequate analgesiaPseudo-addictionA 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 effectivelyDependenceA 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.ToleranceA 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 managementAppropriate Non-Medical & medications for pain reliefInterventional pain management
50 Aims of Medical Treatment Treatment of Acute PainSource + Pain ControlNon Pharmacological methodsNSAIDs for a very short periodParacetamol in adequate dosesTramadol + Paracetamol in adequate dosesRegional analgesiaTreatment of Chronic Pain with Tissue DamageSource + Pain Control + Correcting neuropathy/ central sensitizationTreatment of Chronic Pain Without Tissue DamageCorrecting neuropathy/ central sensitizationTreatment for peripheral sensitizationNa-Channel blocker, Ca-Channel blockerTreatment for central sensitizationNMDA antagonist, Ca-Channel blocker, Opioids, drugs inhibiting Sub P, drugs enhances inhibitory synapses.Restoration of descending inhibitory pathwaysTramadol OR Tricyclics
51 Treatment of Pain Recovery? Strong opioids Missing link Surgical Destruction of Neuro-pathwaysStrong opioidsMissing linkBetween Med & Sx MxWeak opioids +/- non-opioids +/- adjuvantNon-opioidsNon-pharmacological methods
54 NSAIDSNSAIDs are the most widely prescribed drugs for the treatment of acute and chronic pain , which account for about 6 to 7 billion dollars P.A in sales worldwide.
55 NSAIDS- mechanism of action Differencesinisomer activityCentralactionMultiple isoforms of cyclooxygenaseAppears to be more involved than previously thought peripheral action only.
56 NSAIDs: Mechanism of Action Inhibits cyclooxygenase- prevents sensitization of peripheral Nociceptors by diminishing PG formation- most commonly stated.Cellular effects unrelated to PGs-inhibits release of inflammatory mediators from neutrophils & macrophages.Also produces analgesia through CNS mechanism- by reversing inhibition by PGs of opioid-mediated pain modulation
57 COX selectivty- 4 classes I- Aspirin- irreversible inhibition of both COX-1 & COX-2.II- Ibuprofen-reversible competitive inhibition of both isoforms.III-Flurbiprofen-slower time dependent inhibition of both isoforms. Also enhances NO production in gastric mucosaIV-Celecoxib- largely COX-2 selective
58 Toxicity Gastrointestinal effects. Cardiovascular effects. Renal toxicityRenal impairment in 18%, ARF in 6% using NSAIDs. Clinically significant in patients with Heart failure, Renal insufficiency & Liver diseaseHepatic toxicity.Liver related side effects reported in 3% users.Sulinduc creates higher risk of hepatic damage, although mild& reversible.Diclofenac with fulminant hepatitis reportedAllergy and hypersensitivity.Hematologic effects.Aspirin inhibits platelet activation irreversibly- takes 7-10 days to recover.Non-aspirin NSAIDs include reversible platelet inhibition – resolves when drug is eliminatedMost NSAIDs potentiate anticoagulant activity of warfarin.CNS effects.
59 NSAIDs- GI toxicityRiskThe ARAMIS model for estimating risk of Gastric ulceration while taking nonselective NSAIDs.A score > 1.5 is considered high risk and a contraindication for the use of nonselective NSAIDs.The scale is for chronic use over a 12 month period.Age > 50 yearsPast history of peptic ulcerSteroid useAlcohol useMultiple NSAIDs useFirst 3 months of useStep 1 Start at a score of 0 Step 2 Add 0.3 for every 5 y of patient’s age over 50 y Step 3 Add 1.2 if the pt is receiving a corticosteroid Step 4 Add 1.4 if the pt has reported a previous NSAID- related GI side-effects Step 5 Add 0.5 if the pt has sustained disability
65 Other Adjuvants Anticonvulsants Traditionally used for neuropathic pain-carbamazepine and phenytoin.Newer agents- gabapentin, pregabalin, lamotrigine.Gabapentin and carbamazepine- are more evidence based.Pregabalin and lamotrigine- no systematic review or meta-analysis of trials available at present.Pregabalin – higher doses(300 to 600 mg/day) produces more consistent results than lower doses(75 to 150 mg/day).Complications: sedation-somnolence, fatigue, dry mouth etc.AntidepressantsAlso traditionally used for neuropathic pain.TCAs may be most effective classes of drugs.Amitriptyline – NNT=2, desipramine-NNT=2.1Not effective in HIV-related neuropathies.Other RxLidocaine and mexiletine are equivalent to morphine, gabapentin, TCAs .Lidocaine IV up to 5mg/kg over 3 to 45 min.Mexiletine 100 to 200mg three times per day(upto 675mg TID reported).Lidocaine 5% transdermal also effective2-adrenergic receptor agonist- clonidineNMDA receptor antagonist (Ketamine..)capsaicin
71 Interventional Pain Management are some minimally invasive procedures done under image guidance which gives permanent/long term pain relief by stopping nociceptive inputs or correcting neuropathy.It fills the gap between pharmacologic management of pain & more invasive operative procedure. (The missing link)IPM
72 Interventional Pain Management John Bonica‘The Godfather ‘of InterventionalismNorman Harden Center for Pain Studies Rehabilitation Institute, Chicago Northwestern University
76 Pros & Cons Bridges the gap Targeted therapy Invasive but Safe in Skilled handsCostPatient/Procedure selection
77 Scope for IPM…..Neuralgias e.g. Trigeminal Neuralgia, Post Herpetic neuralgia, Migrain/CH, IFPChronic spinal Pain XDs e.g. Facet J. A, Discogenic Pain, FBSSVertibroplastyComplex Regional Pain XDCancer Pain
78 Most Important Consideration of IPM….. Correct Procedure on Correct patient.
79 Questionnaire…? wathupitiwala\Wathupitiwala.doc 1. Pleases select the type of your practiceGeneral Practitioner 12%Specialist 88%Other (please specify)2. If you consider all pain syndromes…All can be treated successfullyMany can be treated successfully 56%Some can be treated successfully 38%A few can be treated successfully 6%
80 3. Why in your opinion some patients cannot be cured of pain? Wrong diagnosis 34%Wrong / inadequate treatment (including not enough drug categories/ groups) 50%Late presentations 19%Pain has become a disease 37%There is a missing link between medical& surgical management of pain 35%Drug addicted patients 3%4. Can you enumerate such difficult situations (mainly chronic pain condition) you came across and how did you manage get away with those (chronic) patients?abc
81 5. If your patient has a chronic pain, If he/she is not a drug addict and if Psychiatric assessment is normal,…also if there is no medically or surgically correctable cause....what can you offer them?Ignore their complains and discharge from follow up 9%Continue a cocktail of analgesics/adjuvant drugs 27%Prescribe them anti-depressants anyway 35%Continuously investigating them for a cause 35%Other (please specify) 6. What are the various modalities of pain treatment available except treating underlying condition, specifically for chronic pain conditions?TENS (transcutaneous electrical nerve stimulation) therapy 56%Meditation 65%Relaxation / Distraction techniques 65%Visual imagery, as simple as picturing a peaceful scene, for example 37%Biofeedback, which teaches control over muscle tension, temperature, heart rate and more 53%Heat, cold or irritant application 65%Manipulation and massage 60%Surgically destroying pain pathways 60%Other (please specify) 22%
82 7. If your patient is not benefiting all these and not consenting or not a candidate for surgery…is there a possible escape route?Yes 69%If "Yes" what would be that possible modality???No 31%