Prognostic accuracy of severity score for prolonged ICU length of stay >72 hours in general surgical ICU: a prospective study

Introduction

Prolonged ICU stay is associated with high morbidity, mortality and costs [1, 2]. Prediction of this prolonged stay will provide information for physician and family and help with resource allocation. Even though, available severity scoring system ie. APACHE II, APACHE III, MPM, SAPS II, MODS scores are widely accepted for evaluating outcomes in the ICU population. But these models might be inaccurate when apply to subpopulation and might not predict prolonged length of stay. The objective of this study was to refine ASA physical status and five severity scores (APACHE II, APACHE III, SOFA, SAPS, MOFS) in order to predict prolonged length of stay in the adults patients admitted to the general surgical ICU.

Methods

This prospective observational study was done in 948 adult surgical patients admitted to the general surgical ICU at Siriraj Hospital during 1 January 2005 to 31 December 2005. A prolonged length of stay was defined as staying in the ICU >72 hours. Preoperative ASA physical status and five severity scores as APACHE II, APACHE III, SOFA, SAPS, MOFS on day 1 were registered and calculated. We analyzed the relationship of each severity score and outcome as prolonged ICU length of stay.

Results

Prolonged length of stay represented 20.1% of ICU admissions. Among severity scores, ASA physical status IV (P < 0.001), emergency ASA (P < 0.001), APACHE III (P = 0.025) were significantly associated with prolonged ICU length of stay (>72 hours) while MODS was most likely associated with this prolonged length of stay (P = 0.059). From multivariate analysis, only ASA physical status IV (OR 6.503 (2.314 to 18.275), P < 0.001) and emergency ASA (OR 4.52 (2.86 to 7.12), P < 0.001) were significantly associated with prolonged ICU length of stay (>72 hours).

Conclusions

The study was conducted in 948 adult surgical patients admitted to the general surgical ICU at a 3rd referral university hospital. Among all of the severity scores, ASA physical status IV and emergency ASA were significantly correlated with prolonged ICU length of stay >72 hours.