Risk factors for post-operative wound infection in cardiac surgery patients.

In a prospective study of 372 patients undergoing cardiac surgery, we evaluated the relative contribution of host factors and patient care variables to the risk of post-operative wound infection. Host factors studied were age, sex, country of origin, the diagnosis for which the operation was performed and, for coronary artery by-pass operations, the functional cardiac status according to modified New York Heart Association criteria. The performance of more than one operation during a single admission carried the highest risk for infection, followed by a coronary artery by-pass operation lasting for more than six hours or performed on patients 65 years or older. In patients undergoing coronary artery by-pass surgery, host factors (age and cardiac function) were associated with infections in the chest wound, while the length of the operation was found to affect the occurrence of infections at the "donor" site.