|American Society of Anaesthesiologists grading|
|I||Healthy individual with no systemic disease|
|II||Mild systemic disease not limiting activity|
|III||Severe systemic disease that limits activity but is not incapacitating|
|IV||Incapacitating systemic disease which is constantly life-threatening|
|V||Moribund, not expected to survive 24 hours with or without surgery|
Duff et al.
Duff et al. BMC Surgery 2012 12:14 doi:10.1186/1471-2482-12-14