Determinants of Prolonged Length of Hospital Stay After Coronary Bypass Surgery

The length of hospital stay after coronary surgery was studied in 4,683 patients undergoing cardiac catheterization followed by coronary surgery at Emory University Hospital or Crawford Long Hospital between the years 1981 and 1986. Length of stay after coronary surgery had a median and modal value of 7 days. There was, however, a long statistical tail of patients with a prolonged length of stay extending out to more than 180 days. Prolonged length of stay (>10 days) could be correlated with preprocedural variables such as age, elective versus emergency status, angina class, ejection fraction, and gender. Length of stay increased from a mean of 6.9±1.4 days under the age of 40 years to 10.9±12.1 days over the age of 70 years (p < 0.0001). Length of stay was correlated with the periprocedural variables of wound infection, neurologic event, arrhythmias, pneumonia, postoperative myocardial infarction, mortality, and pericarditis. Length of stay increased from 8.8±9.6 days without a neurologic event to 21.1±17.9 days with a neurologic event (p < 0.0001). Similarly, without a wound infection, the average stay was 8.7±8.9 days; with a wound infection, the average stay was 32.2±25.8 days (p < 0.0001). The correlates of prolonged stay were tested in another population comprising 781 patients undergoing cardiac catheterization followed by coronary artery bypass grafting in 1987. The predictors of prolonged stay in the 1987 population were wound infection, pneumonia, arrhythmias, age, neurologic events, postoperative infarction, and ejection fraction. Thus, length of hospital stay after coronary surgery may be predicted by multiple preprocedural and periprocedural variables. The ability to determine outliers with extremely prolonged stay seems unlikely from clinical or angiographic vanrables. Unusually prolonged stay appears to depend on the occurrence of relatively uncommon but severe complications.