Predicting prolonged intensive care unit length of stay in patients undergoing coronary artery bypass surgery--development of an entirely preoperative scorecard.

We sought to develop a predictive model based exclusively on preoperative factors to identify patients at risk for PrlICULOS following coronary artery bypass grafting (CABG). Retrospective analysis was performed on patients undergoing isolated CABG at a single center between June 1998 and December 2002. PrlICULOS was defined as initial admission to ICU exceeding 72 h. A parsimonious risk-predictive model was constructed on the basis of preoperative factors, with subsequent internal validation. Of 3483 patients undergoing isolated CABG between June 1998 and December 2002, 411 (11.8%) experienced PrlICULOS. Overall in-hospital mortality was higher among these patients (14.4% vs. 1.2%, P<or=0.0001). The following variables were found to be independent predictors of PrlICULOS: increased age, recent myocardial infarction, preoperative renal failure, cerebral and/or peripheral vascular disease, chronic obstructive pulmonary disease, ejection fraction <40%, previous CABG, triple-vessel and/or left main disease, NYHA class IV symptoms and urgent or emergent status. Subsequent validation of this model demonstrated a c-statistic of 78%. An internally-validated, risk predictive model of PrlICULOS in patients undergoing CABG was constructed. Based on preoperative clinical factors, a scorecard was developed allowing identification of these patients prior to surgery and allowing for strategies aimed at optimizing hospital resources.