365 Ch 364. Pain: Acute, Chronic, and Neuropathic

Pain = “unpleasant sensory + emotional experience” (IASP 2020 revised)；acute vs chronic (> 3 months)；nociceptive (somatic, visceral) vs neuropathic (peripheral, central) vs nociplastic (altered nociception without clear damage — fibromyalgia, IBS, central sensitization)；WHO analgesic ladder: Step 1 (mild) — non-opioid (NSAID, acetaminophen) ± adjuvant; Step 2 (moderate) — weak opioid (tramadol, codeine) + non-opioid ± adjuvant; Step 3 (severe) — strong opioid (morphine, oxycodone, hydromorphone, fentanyl) + non-opioid ± adjuvant；opioid crisis has shifted prescribing — minimize opioids, multimodal approach；neuropathic pain = gabapentin/pregabalin + duloxetine/venlafaxine + TCA (amitriptyline/nortriptyline) + topical lidocaine + capsaicin；chronic pain management = multidisciplinary biopsychosocial。