Table 1.

ASA physical status classification system

ASA PS classification	Definition	Examples, including but not limited to:
ASA I	A normal healthy patient	Healthy, non-smoking, no or minimal alcohol use
ASA II	A patient with mild systemic disease	Mild diseases only without substantive functional limitations. Examples include (but not limited to): current smoker, social alcohol drinker, pregnancy, obesity (30<BMI<40), well-controlled DM or HTN, mild lung disease.
ASA III	A patient with severe systemic disease	Substantive function limitation; one or more moderate to severe diseases. Examples include (but not limited to): poorly controlled DM or HTN, COPD morbid obesity (BMI>40), active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction or ejection fraction. ESRD undergoing regularly scheduled dialysis, history (>3 months of MI, CVA, TIA or CAD/stents).
ASA IV	A patient with severe systemic disease that is a constant threat to life	Examples include (but not limited to) recent (<3 months) MI, CVA, TIA or CAD/stents ongoing cardiac ischaemia or severe valve dysfunction, severe reduction or ejection fraction, sepsis DIC, ARD or ESRD not undergoing regularly scheduled dialysis.
ASA V	A moribund patient who is not expected to survive	Examples include (but not limited to) ruptured abdominal/thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischaemic bowel in the face of significant cardiac pathology or multiple organ/systemic dysfunction.
ASA VI	A patient declared brain dead whose organs are being removed for donor purposes

ARD, acute respiratory distress; BMI, body mass index; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; CVA, cerebrovascular accident; DIC, disseminated intravascular coagulation; DM, diabetes mellitus; ESRD, end-stage renal disease; HTN, hypertension; MI, myocardial infarction; PS, physical status; TIA, transient ischaemic attack.