The effect of thorough preoperative disinfection on the incidence of postoperative mediastinitis.

This study was conducted to evaluate the effectiveness of scrubbing the skin of patients scheduled to undergo elective cardiac surgery with disinfectant solutions in an attempt to reduce the incidence of the potentially fatal postoperative complication of mediastinitis. Since April 1991, we have routinely disinfected the skin of all such patients three times preoperatively. A retrospective comparison of the incidence of mediastinitis before and after April 1991 was carried out. Microbiological examinations of the anterior chest were conducted in ten patients admitted for elective operations, and in four patients admitted for emergency surgery. Specimens were obtained before each scrubbing, before the operation, and just after skin closure. There was a significant decrease in the general incidence of mediastinitis after April 1991 (P < 0.01). Microbiologically, significant decreases in colony counts were also observed after the first (P < 0.05) and second scrubbing (P < 0.05) in the ten patients specifically studied before elective surgery. No colonies grew in the postoperative specimens from any of these patients, but colony formations were observed in two of the four patients who underwent emergency surgery (P = 0.066). Thus, we conclude that our thorough disinfection method effectively achieves adequate, prolonged suppression of the skin flora, which explains the marked decrease in the incidence of mediastinitis in our hospital since its institution.