Class l Normal, healthy patient without organic, physiological, or psychiatric disturbance
Class ll Controlled medical conditions without significant systemic effects
Class lll Medical conditions with significant systemic effects, intermittently associated with significant functional compromise
Class lV Medical condition poorly controlled and associated with significant dysfunction and a potential threat to life
Class V Critical medical condition associated with little chance of survival with or without the surgical procedure
Class Vl Brain dead and undergoing anaesthesia for the purposes of organ retrieval and donation.