The Surgical Procedure Assessment (SPA) score predicts intensive care unit length of stay after cardiac surgery

Objective: The ability to predict intensive care unit length of stay greatly facilitates triage and resource allocation for postoperative cardiac surgical patients in the intensive care unit. We developed a simple, intuitive Surgical Procedure Assessment score that integrates surgical complexity (1, low; 2, intermediate; 3, high) with patient comorbidity (A, minimal; B, substantial). We hypothesized that the Surgical Procedure Assessment score would predict intensive care unit length of stay, discriminate preoperatively between fast-track and prolonged-stay patients, and compare favorably with more complex risk scores.

Methods: After institutional review board approval, 1201 cardiac surgical patients were preoperatively assigned a Surgical Procedure Assessment score, as well as a Parsonnet, Tuman, Tu, and Cardiac Anesthesia Risk Evaluation score. We compared these scores with regard to prediction of intensive care unit length of stay, as well as their concordance in predicting intensive care unit length of stay of less than 48 hours (fast track) and more than 7 days (prolonged stay).

Results: Intensive care unit length of stay increased significantly with increasing Surgical Procedure Assessment scores (P < .01, Cuzick's test for trend). The lowest Surgical Procedure Assessment score (1A) predicted intensive care unit length of stay of less than 48 hours, and the higher Surgical Procedure Assessment scores (2B or 3) predicted intensive care unit length of stay of more than 7 days more accurately than the Parsonnet, Tuman, Tu and Cardiac Anesthesia Risk Evaluation scores.

Conclusions: The Surgical Procedure Assessment score predicts intensive care unit length of stay better than other comparable scores. It is simple, intuitive, and easily understood by all caregivers and can preoperatively discriminate fast-track from prolonged-stay patients. It is a useful tool to facilitate intensive care unit triage.