Risk factors for prolonged stay in the intensive care unit and on the ward after cardiac surgery

Background: Prolonged length of stay (LOS) after cardiac surgery has been associated with poor outcome and a considerable expenditure of health care resources. As our patient's demographics are changing, a continuing evaluation of the preoperative and intraoperative variables affecting LOS in the intensive care unit (ICU) and on the floor remains important. Methods: This is a prospective study examining the determinants of prolonged LOS in 426 consecutive patients after cardiac surgery. Univariate and multivariate analyses were performed for an ICU stay >= 2 days and for a stay on the floor > 7 days. Secondary outcome was the incidence of postoperative complications. Results: Among all patients, 27.7% had a prolonged stay in the ICU. Univariate analysis revealed 13 perioperative variables that were significantly associated with prolonged stay. Independent predictors for extended ICU LOS included an ejection fraction < 40% (RR 1.83; p = 0.04), high Parsonnet score (RR 2.23; p = 0.012), history of renal failure (RR 5.39; p = 0.001), and an emergency surgery (RR 2.43; p = 0.007). Furthermore, 30.5% of patients had an extended stay on the floor with female gender (RR 1.93; p = 0.009) and age (RR 2.55; p = 0.0001) being two independent risk factors. Conclusions: In this series of 426 consecutive patients, we have identified several perioperative risk factors associated with prolonged hospitalization that can help clinicians in their preoperative patient counseling, risk stratification, and selection. However, the most obvious use of these results is in allowing decision makers to implement specific strategies that would best allocate resources depending on the risk profile of cardiac patients.