[Antibiotic prophylaxis in cardiac surgery: 12-hour cefazolin versus 36-hour cefazolin]

A prospective randomized study was carried out to assess two protocols of antibiotic prophylaxis in patients undergoing cardiac surgery with cardiopulmonary by-pass. Each patient of the first group received four intravenous injections of 1 g cefazolin over a period of 12 h, whilst in the second group each one received twelve doses over a period of 36 h. Between May 1983 and April 1984, 159 patients scheduled for cardiac surgery entered the study. Those who underwent emergency surgery, or weighed less than 20 kg, or received antibiotics in the week before surgery, or had a previous history of anaphylaxis to cephalosporins were not included in the study. Both groups were similar in their distribution of age, weight, height, sex, past history of infectious disease, surgery and iatrogenic factors. There were no significant differences between the two groups in the number of minor infections and bacterial floral changes. There were no major infections either (septicaemia, mediastinitis, endocarditis). Temperature charts were the same on the first four days. The length of stay at hospital was the same in both groups. Since the efficacy of the two protocols in preventing major infections was the same, the authors recommend the short prophylaxis with cephazolin for cardiac surgery patients.