Determinants of Intensive Care Unit Length of Stay for Infants Undergoing Cardiac Surgery

Abstract

The purpose of this study was to identify factors that influence postoperative intensive care unit length of stay (ICULOS) in infants less than 6 months of age undergoing congenital heart surgery. Records from a single institution, from January 2000 to December 2000, were reviewed. For analysis, surgical severity was characterized using an ordinal scoring system, the Aristotle Basic Complexity Score (ABCS; range 1-4). Of 221 infants, 63 had elective surgery, that is, admission to the cardiac intensive care unit after surgery, and 158 had nonelective surgery with admission to the cardiac intensive care unit preoperatively. Elective vs. Nonelective groups differed: ABCS (median 2 vs. 3, P < .001), age at surgery (mean 110 + 10.5 vs. 27 + 3.7 days, P < .001), ICULOS (median 3.5 vs. 7 days, P < .000), and mortality (0% vs. 12.7%P < .0001). Step-wise multiple regression was performed using the natural log of ICULOS as the dependent variable. Factors associated with longer ICULOS for all 221 patients included: increasing ABCS, preoperative organ-system failure, total support time (= cardiopulmonary bypass time + deep hypothermic circulatory arrest time), total hours of postoperative ventilatory support, the need for postoperative cardiac catheterization, postoperative necrotizing enterocolitis, and postoperative nasogastric feeds. Higher preoperative weight and surgical repair vs. palliation were associated with a decrease in ICULOS. In conclusion, preoperative organ dysfunction, need for nasogastric feeding, and total support time may offer measurable variables useful in predicting that infant at greatest risk for extended ICULOS.