ASA Physical Status Classification
American Society of Anesthesiologists (ASA) physical status classification grades peri-operative risk based on patient's overall health. Used for all anaesthetic risk assessments.
Score interpretation
Healthy patient. Mortality < 0.1% for elective procedures.
→ Standard anaesthetic technique. No special precautions required.
Mild systemic disease. Mortality 0.2–0.3%. Elective surgery generally safe.
→ Routine pre-operative assessment. Optimise chronic disease before elective surgery (e.g. HbA1c < 69 mmol/mol for DM, BP < 180/110 for HTN).
Severe systemic disease with functional limitations. Mortality ~1.8%. Benefit of surgery should outweigh risk.
→ Thorough pre-operative assessment. Cardiology/relevant specialist review if needed. Consider regional over general anaesthesia. HDU post-op.
Life-threatening systemic disease. Mortality ~7.8%. Emergency surgery only, or if benefit clearly outweighs risk.
→ Senior anaesthetist and surgeon involvement. ICU/HDU post-op. Goals-of-care discussion. Optimise all reversible pathology before surgery.
Moribund patient. Mortality ~9.4% (emergency). Surgery as life-saving measure only.
→ Surgery only as last resort. ICU team involved pre-operatively. Family informed of extremely high mortality risk. Palliative care team on standby.
Brain-dead patient designated for organ donation.
→ Organ donation protocol. Co-ordinate with specialist nurse for organ donation (SNOD). Maintain organ perfusion.
Interpretation bands for the ASA Classification. Apply clinical judgement and local guidance.
References
- Doyle DJ, Goyal A, Garmon EH. American Society of Anesthesiologists Classification. StatPearls Publishing. 2023.
- ASA House of Delegates. ASA Physical Status Classification System. American Society of Anesthesiologists, 2020.
Related
Curated clinical cross-links plus same-class fallbacks.
- Ketamine (Perioperative — Opioid-Sparing Analgesia) · NMDA Receptor Antagonist (Dissociative Anaesthetic / Analgesic)
- Rivaroxaban (Perioperative VTE Prophylaxis) · Direct Oral Anticoagulant — VTE Prophylaxis Post-Surgery
- Propofol · Anaesthetic (IV Induction / Sedation)
- Ketamine (Anaesthesia/Sedation) · Dissociative Anaesthetic (NMDA Receptor Antagonist)
- Propofol (TCI / TIVA) · Intravenous Anaesthetic Agent
- Sevoflurane · Volatile Inhalational Anaesthetic
- Major Trauma — Primary Survey (ATLS) · ATLS 10th Edition; JRCALC; NICE NG39
- Major Haemorrhage / Massive Transfusion · BCSH; RCOA; RCEM; RCS — BCSH Guidelines
- Burns — TBSA Estimation & Fluid Resuscitation · British Burn Association; EMSB; RCEM 2024
- Lower Gastrointestinal Bleed · NICE; BSG; ACPGBI — Commissioning Guide
- Acute Pancreatitis · NICE; IAP/APA; ACPGBI — CG104
- Hypertrophic Pyloric Stenosis · BAPS / RCPCH
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.