Determinants of duration of ICU stay after coronary artery bypass graft surgery

Prediction of duration of a patient's stay in the ICU after cardiac surgery is difficult. In 652 consecutive adult patients undergoing elective coronary artery bypass graft (CABG) surgery, we analysed prospectively preoperative and immediate postoperative variables thought to influence duration of stay in the ICU. With univariate analysis, we found that age, preoperative left ventricular ejection fraction, bypass time, aortic cross-clamp time, blood transfusions and the number of inotropic agents administered in the immediate postoperative period (for at least 6 h) were significant correlates of duration of stay in the ICU. However, logistic regression analysis showed that the number of inotropes was the most important determinant of stay in the ICU, with an overall prediction accuracy of 94.8%. The main cause of prolonged stay in the ICU (more than 2 days) was low cardiac output syndrome. We conclude that analysis of perioperative variables enhanced our ability to accurately predict duration of stay in the ICU in cardiac surgery patients. The number of inotropic agents administered during the first 6 h after operation was the most important determinant of duration of stay in the ICU.