Table 5

American Society of Anaesiologists' status classification: modified from Wolters and colleagues [10]

Class

Description

Mortality (%)

I

Healthy

0.1

II

Mild systemic disease – no functional limitation

0.7

III

Severe systemic disease – definite functional limitation

3.5

IV

Severe systemic disease – constant threat to life

18.3

V

Moribund patient unlikely to survive 24 hours with or without operation

93.3

E

Emergency operation

Boyd and Jackson Critical Care 2005 9:390   doi:10.1186/cc3057