Pain Assessment

1. Pain Assessment

2. Clinician-Related Barriers to Pain Assessment • Lack of pain training in medical school • Insufficient knowledge • Lack of pain-assessment skills • Rigidity or timidity in prescribing practices • Fear of regulatory oversight

3. Patient-Related Barriers to Pain Assessment • Reluctance to report pain • Reluctance to take opioid drugs • Poor adherence

4. System-Related Barriers to Pain Assessment • Low priority given to symptom control • Unavailability of opioid analgesics • Inaccessibility of specialized care • Lack of insurance coverage for outpatient pain medication

5. Pain Assessment: Goals • Characterize the pain • Identify pain syndrome • Infer pathophysiology • Evaluate physical and psychosocial comorbidities • Assess degree and nature of disability • Develop a therapeutic strategy

6. Comprehensive Pain Assessment • History • Physical examination • Appropriate laboratory and radiologic tests

7. Pain and Disability Nociception Other physical symptoms Physical impairment Neuropathic Psychologic Social isolation mechanisms processes Family distress Sense of loss or inadequacy Adapted with permission from Portenoy RK. Lancet. 1992;339:1026. Disability Pain

8. Pain History • Temporal features—onset, duration, course, pattern • Intensity—average, least, worst, and current pain • Location—focal, multifocal, generalized, referred, superficial, deep • Quality—aching, throbbing, stabbing, burning • Exacerbating/alleviating factors—position, activity, weight bearing, cutaneous stimulation

9. Nociceptive pain Neuropathic pain Idiopathic pain Psychogenic pain Commensurate with identifiable tissue damage May be abnormal, unfamiliar pain, probably caused by dysfunction in PNS or CNS Pain, not attributable to identifiable organic or psychologic processes Sustained by psychologic factors Pathophysiology

10. Pain Assessment Tools • Pain intensity scales • Verbal rating • Numeric scale • Visual analogue scale • Scales for children • Multidimensional pain measures • Brief Pain Inventory • McGill Pain Questionnaire

11. Nociceptive Pain • Presumably related to ongoing activation of primary afferent neurons in response to noxious stimuli • Pain is consistent with the degree of tissue injury • Subtypes • Somatic: well localized, described as sharp, aching, throbbing • Visceral: more diffuse, described as gnawing or cramping

12. Neuropathic Pain • Pain believed to be sustained by aberrant somatosensory processing in the peripheral or central nervous system • Subtypes • “Central generator” • Deafferentation pain (central pain, phantom pain) • Sympathetically-maintained pain (CRPS) • “Peripheral generator” • Originate in the nerve root, plexus, or nerve • Polyneuropathies, mononeuropathies

13. Idiopathic Pain • Pain in the absence of an identifiable physical or psychologic cause • Pain is perceived to be excessive for the extent of organic pathology

14. Psychogenic Pain • Pain sustained by psychologic factors • More precisely characterized in psychiatric terminology • Patients have affective and behavioral disturbances • Patients with organic component often have concurrent psychologic contributions and comorbidities • “Chronic pain syndrome” sometimes used to depict this phenomenon

15. Acute pain Chronic pain Breakthrough pain Recent onset, transient, identifiable cause Persistent or recurrent pain, beyond usual course of acute illness or injury Transient pain, severe or excruciating, over baseline of moderate pain Pain Syndromes

16. Identify Pain Syndromes • Syndrome identification can direct assessment and predict treatment efficacy • Cancer pain syndromes • Bone pain • Pathologic fracture • Cord compression • Bowel obstruction • Noncancer-related pain syndromes • Atypical facial pain • Failed low-back syndrome • Chronic tension headache • Chronic pelvic pain of unknown etiology