Sensory and emotional experience associated with actualor potential tissue damage
According to Katz and Melzack, pain is apersonal and subjective experience thatcan only be felt by the sufferer.According to McCaffery pain is whateverthe experiencing person says it is andexists whenever they say it does.
TYPES OF PAIN ACUTE PAIN CHRONIC PAIN CUTANEOUS PAIN DEEP SOMATIC PAIN VISCERAL PAIN REFERRED PAIN NEUROPATHIC PAIN PHANTOM PAIN
Behavioralcharacteristics Facial expressions- grimace, clenched teeth,wrinkled forehead, crying Body movements -restlessness, immobilization,muscle tension, protective movement of bodyparts Social interaction- avoidance of conversation &contacts
FACTORS INFLUENCINGPAIN PHYSIOLOGICAL SOCIAL SPIRITUAL PSYCHOLOGICAL CULTURAL
Post operative pain Acute Nociceptors and Neuropathic pain Surgical pain
Why is control important Delays post op recovery Increases morbidity Delays return to normal function Restricts mobility -> thromboembolism Catecholamine release Pulmonary dysfunction
Assessment Pre op prediction Post op subjective assessment Post op objective assessment
Initial Pain Evaluation The initial evaluation of pain should include adescription of the pain using the PQRSTcharacteristics: P Palliative or provocative factors: ‘What makes itless intense?’ Q Quality: ‘What is it like?’ R Radiation: ‘Does it spread anywhere else?’ S Severity: ‘How severe is it?’ T Temporal factors: ‘Is it there all the time, or does itcome and go?’
To study the effects of both physical and non-physical influences onpatient well-being, an instrument must assess more dimensions than the intensity of pain or otherphysical symptoms. Several validated questionnaires to assess various QoL dimensions are available,including the Medical Outcomes Short-Form Health Survey Questionnaire 36 (SF-36), and the EuropeanOrganisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC QLQ-C30) (26-30).There are several rating scales available to assess pain. Rating painusing a visual analogue scale (VAS, Figure1) or collection of VAS scales (such as the brief pain inventory) is anessential part of pain assessment. Itsease of use and analysis has resulted in its widespread adoption. It is,however, limited for the assessment ofchronic pain.
Pre op assessment Past medical and surgical history Current Rx (prescribed and illicit) Allergies Past pain history and treatments Patients expectations of pain Advice re pain Mx and modes of delivery How we measure pain and patients reporting
Subjective assessment Pain scales - single dimensional and multidimensional
Objective Look at the patient Physiological parameters Functional parameters
ABCDE for pain assessment&management Ask about pain regularly Believe the patient and family in their reports &whatrelieves it Choose pain control options appropriate for thepatient Deliver interventions timely, logical &coordinatedfashion Empower patient and their families
JCAHO Standards for postoperativepain management are: Recognize patients’ rights to appropriateassessment and management of pain Screen for pain and assess the nature andintensity of pain in all patients Record assessment results in a way that allowsregular reassessment and follow-up Determine and ensure that staff are competentin assessing and managing pain. Address pain assessment and managementwhen orienting new clinical staff
Standards Contd.. Establish policies and procedures that supportappropriate prescribing of pain medications Ensure that pain doesn’t interfere with a patient’sparticipation in rehabilitation Educate patients and their families about effectivepain management
PRINCIPLES OF PHARMACEUTICALPAIN MANAGEMENT Provide medication in adequate doses. Utilize a preventive approach to pain relief. Useround the clock dosing with rescue medicationavailable. Closely assess clients with particular diligencewith first doses or when medication dose or thetype is changed Combinations of analgesics may be moreeffective than those given singularly.
PRINCIPLES CONTD. Understand and be prepared to treat sideeffects of medications avoidance of non-life threatening sideeffects (such as constipation, nausea,pruritis) more important that providing painrelief. These concomitant conditions areeasily treated. Additions of adjuvant medications enhancepain relief.
Principles contd. Believe the patient’s report of pain. Maintain a therapeutic relationship thatfacilitates mutual trust. Do not use placebos for pain. incorporate the goal of total pain relief intothe pain management regimen operate as a team to provide the mosteffective pain relief outcomes
PRINCIPLES CONTD. Asking for pain medication reflects the need forpain relief in 99.9% of people with pain anddoses does not reflect an addictive personality. Recognize that respiratory depression is a rareoccurrence, occurring most commonly amongclients who are over sedated. Respiratorydepression rarely occurs after the first fewdoses of an opioid.
Principles contd. Only the patient and no one else can determine theamount of pain experienced There are no objective indicators that can beobserved by another
Practicalities Pre op assessment Prediction of pain Preempt with preventative Rx Assess post op subjectively and objectively Treat with appropriate Rx Assess response Modify Mx
The concept of pre-emptive analgesia wasintroduced in by Woolf who demonstrated throughexperimental studies that post injury painhypersensitivity results via a central mechanism.
Concept of pre-emptive anlgesia is introducedbecause of the greater understanding of painmechanism. Analgesic is introduced before the painfulstimulus……. Prevents,1. central sensitization and amplification ofpostoperative pain.2. covers both the operative and postoperativeperiod.
Therapies that have been tested in pre-emptivetrials include NSAIDS, intravenous opioids,peripheral local anaesthetics, caudal and epiduralanalgesia, dextromethorphan and gabapentin .
Tissue injuries cause an increase in theexcitability of dorsal neurons in the centralnervous system, which is a normal physiologicresponse, and contribute to the postoperativepain. Afferent noxious stimulus could be interrupted atthe periphery, afferent input in sensory axons, andcentral neurons
Local tissue infiltration has long been establishedas a reliable pain relief technique. The mainadvantages of this technique are its simplicity,safety and low cost. The agent most widely usedfor this purpose is 0.25% bupivacaine.
It has been suggested that preoperative infiltrationof local anesthetics provides a greater reduction inpostoperative pain than perioperative orpostoperative infiltration. . The local infiltration of anesthetic blocks C-fiberinput to the dorsal horn and may thereby inhibitcentral sensitization.
Local aneasthetics infiltration has also been used inpercutaneous nephrolithotomy (PCNL) to increasethe patients comfort and reduce the pain andanalgesic requirements postoperatively in avariety of procedures likeherniorrhaphy,chlecystectomy and PCNL etc.