anaesthesia surgery

ASA Physical Status Classification

American Society of Anesthesiologists (ASA) physical status classification for perioperative risk. Guides anaesthetic planning and consent.

Score interpretation

ASA I–II: Low perioperative mortality (0.08–0.27 %)

Vacanti 1970: postoperative mortality ASA I 0.08 %, ASA II 0.27 %.

→ Standard anaesthesia; routine monitoring; elective or emergency cases managed normally

ASA III: Moderate risk (~1.8 %)

Vacanti 1970: postoperative mortality ASA III ~1.8 %.

→ Enhanced monitoring (arterial line); HDU/ICU post-op; optimise comorbidities preoperatively

ASA IV: High risk (~7.8 %)

Vacanti 1970: postoperative mortality ASA IV ~7.8 %.

→ Senior anaesthetist; ICU post-op; detailed risk/benefit discussion; consider regional over general

ASA V-VI: Critical / End-stage

ASA V: moribund (Vacanti 1970 mortality ~9.4 %); ASA VI: brain-dead organ donor.

→ Emergency or organ donation only; maximum monitoring; ICU; multidisciplinary decision-making

Interpretation bands for the ASA Classification. Apply clinical judgement and local guidance.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.