Clinical audit of a respiratory intensive care unit – evaluating outcomes via the acute physiology and chronic health evaluation II system

Abstract

Background: The acute physiology and chronic health evaluation II (APACHE II) score is widely used to assess illness severity and predict mortality in critically ill patients. This study evaluated its usefulness for mortality prediction in a respiratory intensive care unit (RICU). Methods: A prospective observational study included 80 consecutive RICU admissions over six months at a tertiary-care hospital. APACHE II scores were calculated using the worst physiological values recorded during the first 24 hours of admission. Predicted mortality was compared with observed mortality, and associations with age, sex, APACHE II score, and diagnostic category were assessed. Results: Of 80 patients, 54 survived and 26 died, giving an observed mortality of 32.5%. Mean age was 42.1±20.642.1/pm 20.642.1±20.6 years, mean APACHE II score was 12.43±10.812.43/pm 10.812.43±10.8, and mean predicted mortality was 23.9%. Non-survivors were older and had significantly higher APACHE II scores than survivors (p=0.0001, p=0.0001, p=0.0001 and p=0.001, p=0.001, p=0.001, respectively). Mortality increased with advancing age and higher APACHE II score categories, reaching 80% among patients with scores of 30–34 and >34. Male patients had higher observed mortality than female patients (44.68% versus 15.15%; p=0.006, p=0.006, p=0.006). Respiratory and trauma cases had the highest observed mortality (66.66% each). Conclusions: APACHE II is a useful tool for early risk stratification of RICU patients. Higher APACHE II scores and older age were strongly associated with mortality; however, the score underestimated overall mortality in this cohort. Periodic local validation is recommended.