Can we Make an Early Prediction of who will be Discharged from the Intensive Care Unit the Day After Heart Surgery?

Introduction: Most of the patients undergoing heart operation are discharged from the intensive care unit the day after their operation. The aim of this study was to evaluate preoperative, intraoperative and early postoperative risk factors for prolonged intensive care unit length of stay (intensive care unit stay greater than 1 day) in cardiac surgery patients. Materials and Methodology: This retrospective study examines the determinants of prolonged intensive care unit length of stay in 2182 consecutive surgical patients. Univariate and multivariate analyses have been performed. Results: 46.76% of all patients had a prolonged intensive care unit length of stay. Multivariate analysis revealed the following independent predictors for prolonged intensive care unit length of stay: Preoperative: Age (p = 0.001), chronic obstructive pulmonary disease (p = 0.049), serum creatinine (p = 0.003), serum total bilirubin (p = 0.048), chronic renal failure requiring dialysis (P = 0.040), intravenous infusion of nitrates (p = 0.014), NYHA class 3 (p = 0.032), left ventricular ejection fraction (p = 0.006). Intraoperative: aortic cross-clamping time (p = 0.04), CPB duration (P < 0.0001), lowest hematocrit on CPB (p < 0.0001), type of operation (p = 0.012), high doses of catecholamine therapy after CPB (p = 0.001). Postoperative: re-exploration (p < 0.0001), massive transfusions (p < 0.0001), arterial pH at ICU admission (p = 0.024). Conclusion: Due to the increasing number of high-risk patients needing cardiac surgery, it is important to identify risk factors for a prolonged intensive care unit length of stay. This can be applied for scheduling patients for cardiac surgery as well as in optimizing intensive care unit resource planning when resources are limited.