The value of prophylactic antibiotics in aorat-coronary bypass operations: a double-blind randomized trial.

Prospective and retrospective studies were performed to determine the efficacy of prophylactic antibiotics in preventing infections in patients undergoing arota-coronary bypass. One-hundred five patients were randomized in a double-blind fashion to receive either methicillin or saline-placebo for 3 days. The over-all infection rate was 26.7% with 48.9% in the control group and 8.6% in the methicillin group (p less than 0.001). Significant sternal wound infection developed in 21.3% of the control group and 0% of the methicillin group (p less than 0.01). Staphylococcus aureus was the predominant organism causing significant sternal infection (methicillin group versus control group, 5.2% and 21.3%; p less than 0.05). The length of postoperative stay in hospital and the number of days with fever was significantly greater in the control group than in the methicillin group (p less than 0.001). During the same period of time, 160 patients were studied retrospectively. Of these, 150 patients received cephalothin prophylaxis and 10 received methicillin. Comparison of the rates of infection in the cephalothin group to the total methicillin group (prospective and retrospective) showed no significant difference. The study clearly demonstrated that a short course of prophylactic antistaphlococcal penicillin or cephalosporin is justified in aorta-coronary bypass.