Anaes SAQs · Anaesthetic adjuncts

Adrenaline — pharmacology and clinical use

Final SAQ — adrenaline (epinephrine) as the direct-acting catecholamine and adrenal medullary hormone; potent agonist at alpha-1, alpha-2, beta-1 and beta-2 (the only endogenous catecholamine with significant beta-2); dose-dependent receptor selectivity (taught formulary tiers; no abstract owns the cut-offs); three great uses — anaphylaxis first-line (IM 500 micrograms, taught standard; community early-access context Najem 2026), cardiac arrest (1 mg IV every 3 to 5 minutes, taught ALS standard; early timing evidence-backed, Ahn 2026), severe asthma; also cardiogenic shock inotrope, local anaesthetic additive, croup (taught indications; endoscopic epinephrine reported to FAIL in refractory malignant bleeding, Chirumamilla 2026); very short half-life about 2 to 3 minutes (taught pharmacology) requiring continuous infusion; most arrhythmogenic catecholamine — VT/VF, hypertension, myocardial ischaemia, hyperglycaemia, hypokalaemia, lactate rise (beta-2 glycolysis NOT lactic acidosis), extravasation necrosis reversed by phentolamine (cohort-exact 31 of 3734, 0.8%, Shyu 2025); versus noradrenaline (adrenaline has beta-2) and phenylephrine (pure alpha-1) (taught comparisons); no audit trigger-ranking carried (no audit paper in refs); cost/environment stewardship scope only (Parkinson 2026); delirium null in older adults (OR 0.97, P 0.9065, Dong 2026).