The use of APACHE III to evaluate ICU length of stay, resource use, and mortality after coronary artery by-pass surgery.

ABSTRACT

OBJECTIVE: To identify patient characteristics that are associated with increased ICU length of stay, resource use, and hospital mortality after coronary artery bypass surgery. DESIGN: Prospective, multicenter study. SETTING: Six tertiary care hospitals. PARTICIPANTS: A consecutive sample of 2,435 unselected ICU admissions following coronary artery by-pass surgery. MATERIALS AND METHODS: Demographic, operative characteristics and APACHE III score were collected during the first postoperative day; and APACHE III scores and therapeutic interventions during the first three postoperative days. Hospital survival and ICU length of stay were also recorded. Multivariate equations were derived and cross-validated to predict hospital mortality, ICU length of stay, and ICU resource use. RESULTS: Unadjusted hospital mortality rate was 3.9% (range 1.0% to 6.0%), mean ICU length of stay was 3.7 days (range 3.2 to 4.7 days), and first 3-day ICU resource use (TISS points) was 99 (range 68 to 116). The range of actual to predicted ICU length of stay varied from 0.86 to 1.26; and resource use from 0.71 to 1.16. CONCLUSIONS: A limited number of operative characteristics, the post-operative acute physiology score (APS) of APACHE III and patient demographic data can predict hospital death rate, ICU length of stay, and resource use immediately following coronary by-pass surgery. These estimates may compliment assessments based on pre-operative risk factors in order to more precisely evaluate and improve the efficacy and efficiency of cardiovascular surgery.