Comparative study of cefamandole versus ampicillin plus cloxacillin: prophylactic antibiotics in cardiac surgery.

A randomized, prospective study of the efficacy of cefamandole naftate versus a combination of ampicillin and cloxacillin was undertaken in 109 adult patients operated on in Leeds during 1979. Sixty patients underwent valve replacement, and 49 had either aortocoronary bypass grafts or other forms of open-heart operation. Teh two groups matched well in age, sex, and type of operation. One gram of either antibiotic was given intravenously during the induction of anesthesia and every 6 hours thereafter for 48 hours. Two additional grams of antibiotic were placed in the prime of the heart lung machine. The overall rate of infection was 7.5% for the entire series, with 1.7% for the group given cefamandole and 13.7% for the group given ampicillin plus cloxacillin (p less than 0.05). The only patient with infection in the former group (1.7%) had sternal wound involvement. Major sternal wound infection occurred in 3 (5.9%) patients in the latter group. All wound infections were caused by Staphylococcus aureus. In 2 of these patients (ampicillin plus cloxacillin group) the infection proceeded to endocarditis. Urinary and respiratory tract infections occurred in 1.9% and 5.9%, respectively, of patients given ampicillin plus cloxacillin. The duration of hospital stay was shorter in the cefamandole group. The results of this study demonstrated that cefamandole confers effective prophylaxis in cardiac operations.