Pain management Study Guide

📖 Core Concepts Pain Management – Multidisciplinary discipline aimed at relieving acute or chronic pain and improving quality‑of‑life, not always total pain elimination. Pain Definition (Nursing) – Pain exists whenever the patient says it exists; it is a subjective experience. Numeric Rating Scale (NRS) – 0 = no pain, 10 = worst possible. 1‑3 = mild, 4‑6 = moderate, 7‑10 = severe. WHO Analgesic Ladder – Stepwise drug selection based on pain severity (mild → moderate → severe). Opioid Risk – Tolerance, dependence, addiction, overdose; risk factors include prior substance‑use disorder, young age, depression, concurrent psychotropics. Adjuvant Analgesics – Medications (e.g., antidepressants, anticonvulsants, ketamine, clonidine) that enhance analgesia or target specific pain mechanisms (neuropathic, CRPS). Multidisciplinary Team – Physicians (anesthesiology, neurology, physiatry, psychiatry), pharmacists, psychologists, PT/OT, nurses, dentists, etc. --- 📌 Must Remember NRS Interpretation – 1‑3 → mild (little interference); 4‑6 → moderate (significant interference); 7‑10 → severe (disabling). WHO Ladder Mild – Paracetamol or NSAID. Mild‑Moderate – Paracetamol + weak opioid (e.g., tramadol) or NSAID + weak opioid. Moderate‑Severe – Strong opioid (morphine, oxycodone, fentanyl). Opioid Formulations – Long‑acting = baseline control; short‑acting = breakthrough pain. NSAID Mechanism – Inhibit prostaglandin synthesis → ↓ inflammation & pain. Neuropathic Pain Drugs – Amitriptyline, gabapentin, pregabalin, duloxetine are first‑line adjuvants. Ketamine (low‑dose) – Provides better acute analgesia than opioids with less nausea/vomiting. Cannabinoids – Current evidence does not support efficacy for pain or opioid‑sparing. TENS – Helpful for diabetic neuropathy; ineffective for lower‑back pain. Pediatric Scales – Oucher (faces), Varni‑Thompson Pediatric Pain Questionnaire, Children’s Comprehensive Pain Questionnaire. --- 🔄 Key Processes Pain Assessment Workflow Ask intensity, quality, location, aggravating/relieving factors, onset. Record NRS score. For children ≤ 8 yr → use Oucher faces; older → self‑report questionnaires. WHO Ladder Decision Path Determine severity via NRS → apply step 1‑3 medication class. Re‑assess after 24‑48 h; if pain persists, “step up” to next tier. Opioid Titration & Switch (Equianalgesic) Calculate total daily dose of current opioid. Use equianalgesic chart to find equivalent dose of new opioid. Reduce calculated dose by 25‑30 % when switching to account for cross‑tolerance. CBT Pain Coping Skill Training Identify pain‑related thoughts → challenge cognitive distortions → practice relaxation/pacing → monitor mood‑pain feedback loop. TENS Application Place electrodes proximal and distal to painful area. Set frequency 80‑100 Hz (conventional) for sensory analgesia; avoid use on lower‑back pain. --- 🔍 Key Comparisons Paracetamol vs. NSAID – Paracetamol: analgesic/antipyretic, minimal anti‑inflammatory effect. NSAID: analgesic + anti‑inflammatory via COX inhibition. Weak Opioid (Tramadol) vs. Strong Opioid (Morphine) – Tramadol: µ‑receptor agonist + serotonin/norepinephrine reuptake inhibition; lower potency, less respiratory depression. Morphine: high µ‑receptor affinity; higher efficacy, higher risk of respiratory depression and dependence. Long‑acting vs. Short‑acting Opioids – LA: steady baseline control, used for chronic pain. SA: rapid onset for breakthrough pain, used PRN. TENS vs. Acupuncture – TENS: electrical stimulation, evidence limited to neuropathic conditions; Acupuncture: needle insertion, studies show no consistent superiority over sham. ACT vs. CBT – ACT: focus on acceptance, mindfulness, values‑driven action; CBT: focuses on restructuring maladaptive thoughts and behaviors. --- ⚠️ Common Misunderstandings “Pain must be eliminated” → Goal is functional pain control, not total abolition. “All opioids are the same” → Potency, duration, and risk profiles differ; equianalgesic conversion is essential. “NSAIDs are safe for everyone” → Risk of GI bleed, renal impairment, and cardiovascular events; assess contraindications. “Acupuncture always works” → High‑quality trials show mixed results; not superior to sham. “Children cannot self‑report pain” → Many can; use age‑appropriate tools (Oucher, questionnaires). --- 🧠 Mental Models / Intuition “Pain Severity → Analgesic Tier” – Visualize a ladder: the higher the NRS, the higher you climb on the WHO ladder. “Opioid Switch = Dose‑Shrink” – When rotating opioids, always subtract 30 % from the calculated equianalgesic dose to buffer cross‑tolerance. “Multimodal = Synergy” – Combining pharmacologic (e.g., NSAID + opioid) and non‑pharmacologic (exercise, CBT) yields greater pain reduction than any single modality. --- 🚩 Exceptions & Edge Cases TENS Ineffective for Low‑Back Pain – Do not prescribe for chronic lumbar pain. Ketamine Only Low‑Dose – High‑dose ketamine causes dissociation; only low‑dose (< 0.5 mg/kg) is recommended for analgesia. Cannabinoids – Not endorsed as first‑line; may be considered only in research settings. Pregnant Patients – Avoid NSAIDs in third trimester; prefer acetaminophen. Elderly with Renal Insufficiency – Prefer acetaminophen; use NSAIDs cautiously. --- 📍 When to Use Which Mild Pain (NRS 1‑3) → Acetaminophen or NSAID. Mild‑Moderate Pain (NRS 4‑5) → Add weak opioid (tramadol) to acetaminophen/NSAID. Moderate‑Severe Pain (NRS 6‑10) → Initiate strong opioid; choose LA formulation for chronic baseline, SA for breakthrough. Neuropathic Pain → Start gabapentin/pregabalin or amitriptyline; consider adding ketamine if refractory. Diabetic Neuropathy → TENS may be beneficial. Acute Post‑operative Pain → Consider low‑dose ketamine adjunct to opioid to reduce nausea/vomiting. Pediatric Acute Pain → Acetaminophen → NSAID → Opioid (only if needed). Chronic Low‑Back Pain → Exercise + manual therapy; reserve opioids for failure of multimodal approach. --- 👀 Patterns to Recognize “High NRS + functional limitation” → Likely need step‑up on WHO ladder. “Pain + mood disturbance + catastrophizing score high” → Prioritize CBT/ACT. “Pain worsens with movement, improves with rest” → Mechanical/structural component → consider physical therapy or manual mobilization. “Pain unresponsive to NSAID → Suspect neuropathic component → add anticonvulsant or antidepressant. “Rapid escalation of opioid dose without relief” → Assess for tolerance, opioid‑induced hyperalgesia, or inadequate adjuvant therapy. --- 🗂️ Exam Traps Trap: “Acupuncture is proven superior to sham.” → Evidence is inconsistent; answer choice stating superiority is wrong. Trap: “TENS is effective for all chronic pain.” → Ineffective for lower‑back pain; only proven for diabetic neuropathy. Trap: “Cannabinoids reduce opioid requirements.” → Current data does not support this claim. Trap: “Long‑acting opioids are appropriate for breakthrough pain.” → LA is for baseline control; breakthrough requires short‑acting agents. Trap: “NSAIDs are first‑line for neuropathic pain.” → Neuropathic pain responds better to anticonvulsants/antidepressants, not NSAIDs. Trap: “All children should be assessed with the Oucher Scale.” → Oucher is for younger children; older children use self‑report questionnaires. ---