ASA Classification
Classify patient physical status for anesthetic and surgical risk assessment.
Important Medical Disclaimer
This calculator is an educational and clinical decision support tool. Results DO NOT replace professional medical evaluation, laboratory tests, or clinical judgment. Always consult a qualified healthcare professional for diagnosis, treatment, and clinical decisions. Calculations are based on scientifically validated formulas but may not be applicable to all patients.
Classification Flow
Answer the questions below to identify the most appropriate ASA class.
Is the patient a brain-dead organ donor?
What is ASA Classification?
American Society of Anesthesiologists (ASA) classification system that assesses preoperative physical status, not surgical or anesthetic risk per se. Developed in 1941, revised in 2014. Classification I to VI based on comorbidities and general state. Suffix 'E' indicates emergency. Used worldwide to standardize communication about patient status.
When to use ASA?
Use in all preanesthetic evaluations to document patient physical status. Useful for team communication, predict need for postoperative intensive care, compare mortality between institutions (adjusting for ASA). Don't use alone to cancel surgery (ASA III can operate safely). Combine with other scores (Goldman, RCRI) for cardiac risk.
Limitations and Considerations
ASA is subjective, with moderate inter-rater agreement (60-70%). Doesn't consider surgery type (minor surgery in ASA IV vs major surgery in ASA II). Doesn't predict specific risk (use RCRI for cardiac risk, ARISCAT for respiratory). ASA was developed for stratification, not for decision to cancel/operate. Same ASA can have very different outcomes depending on surgery.
Frequently Asked Questions about ASA
Can ASA IV operate safely?
Yes, but requires intensive preparation. ASA IV surgical mortality risk: 7.8% (vs ASA I: 0.06%). Many ASA IV operate successfully if optimized (compensate HF, control glycemia, stabilize hemodynamics). Decision depends on: surgery urgency, expected benefit, patient preference. ASA IV is not absolute contraindication.
How to classify patient with multiple comorbidities?
Consider worst condition. Examples: controlled HTN alone = ASA II. HTN + DM without complications = ASA II. DM with nephropathy + HTN = ASA III. Recent MI (<6 months) = ASA IV regardless of other diseases. If doubt between ASA II and III, err to higher (III) is safer.
What does 'E' suffix mean?
Emergency: surgery that must be done as soon as possible due to life risk or limb/organ loss. Examples: perforated appendicitis, trauma, acute arterial ischemia. 'E' increases risk (surgical mortality doubles or triples). ASA IIE has similar risk to elective ASA III. Prepare minimum necessary, don't delay surgery to 'optimize'.
Does ASA work for ambulatory surgery?
Yes. ASA I-II are ideal for ambulatory. ASA III can be ambulatory if stable disease and low-risk surgery (cataract, superficial procedures). ASA IV usually requires admission. Ambulatory discharge criteria: controlled pain, minimal nausea, ambulates, voids, stable vitals. ASA III ambulatory requires more rigorous monitoring.