Preventing deep wound infection after coronary artery bypass grafting: a review.

The consequences of deep wound infections before, during, and after coronary artery bypass grafting have prompted research to clarify risk factors and explore preventive measures to keep infection rates at an irreducible minimum. An analysis of 42 studies in which investigators used multivariate logistic regression analysis revealed that diabetes mellitus and obesity are by far the chief preoperative risk factors. A 4-point preoperative scoring system based on a patient's body mass index and the presence or absence of diabetes is one practical way to determine the risk of mediastinitis, and other risk-estimate methods are being refined. Intraoperative risk factors include prolonged perfusion time, the use of one or more internal mammary arteries as grafts, blood transfusion, and mechanical circulatory assistance. The chief postoperative risk factor is reoperation, usually for bleeding. Unresolved issues include the optimal approach to Staphylococcus aureus nasal colonization and the choice of a prophylactic antibiotic regimen. We recommend that cardiac surgery programs supplement their audit processes and ongoing vigilance for infections with periodic, multidisciplinary reviews of best-practice standards for preoperative, intraoperative, and postoperative patient care.