A fifteen-year wound surveillance study after coronary artery bypass.

Wound infections after coronary artery bypass operations have been continuously monitored at the Minneapolis Veterans Affairs Hospital for 15 years. All patients were followed up for 30 days. From 1977 to 1991, 2,402 coronary artery bypass operations were performed, and wound infections developed in 125 (5%) patients. There were 71 (3%) chest infections of which 33 (1.4%) were major and 38 (1.6%) superficial. Greater than 94% of these grew only a single organism, of which 74% were Staphylococcus species. There were 63 (2.6%) leg wound infections. More than 50% of these grew multiple organisms, of which 68% were enteric in origin. Nine (0.4%) patients had simultaneous chest and leg infections. Wound infections were diagnosed an average of 15.3 +/- 6.7 (range, 4 to 30) days postoperatively, with 50% occurring after discharge from the hospital. Of 14 variables evaluated by multivariate logistic regression analysis, only steroids (p = 0.005) and diabetes (p = 0.003) were identified as independent risk factors for wound infections. Patients taking steroids or with diabetes tended to have chest infections, whereas obese patients tended to have more leg infections (p = 0.08). During an interval in the surveillance program, a trend toward increasing infections was identified and successfully reversed.