Nitrous Oxide Sedation

ASA Physical Status Classification

Definition

Examples

ASA 1

A healthy patient

A fit, nonobese, nonsmoking patient with no underlying disease and good exercise tolerance

ASA 2

A patient with systemic disease that is mild

A patient with no functional limitations and a well-controlled disease, obesity with a BMI 30-40, frequent social drinking, or current cigarette smoking

ASA 3

A patient with systemic disease that is severe but not life-threatening

A patient with some functional limitation due to poorly controlled moderate/severe disease(s), morbid obesity with BMI 40 or above, substance abuse, end-stage renal disease undergoing regular dialysis, implanted pacemaker, or remote history of coronary or intracerebral ischemic event (not within the past 3 months)

ASA 4

A patient with "severe systemic disease that is a constant threat to life"

A patient with substantial functional limitations due to severe, life-threatening diseases, such as coronary or intracerebral ischemic event within the past 3 months, severe end-organ dysfunction (cardiac, pulmonary, renal), ongoing coagulopathy, and shock states

ASA 5

A comatose patient who is "not expected to survive without the operation"

Ruptured aneurysm, multisystem trauma, or extensive intracranial hemorrhage with mass effect

ASA 6

A brain-dead patient whose organs are being procured for transplantation into another patient