The role of cephalosporins in surgical prophylaxis.

Worldwide, cephalosporins are the most widely used antibiotics for surgical prophylaxis. These drugs are recommended for prophylaxis because of their good safety profile, excellent antimicrobial activity against most of the bacteria causing postoperative wound infection, satisfactory penetration into critical tissues and, most importantly, a strong track record of efficacy in clinical trials. There are still unresolved questions about the choice of cephalosporin and the timing and duration of administration. In vaginal hysterectomy, Caesarian section, and biliary tract surgery a single preoperative dose of any one of several cephalosporins has been used effectively. There are no apparent benefits in using a longer course for prophylaxis, nor for choosing a third-generation cephalosporin rather than a first- or second-generation cephalosporin. Several cephalosporins have been employed successfully in cardiac surgery, mostly in trials using a 24-48 h regimen. A recent study with a single preoperative dose of ceftriaxone has produced favourable results. In elective colorectal surgery definitive conclusions are difficult because of limited controlled studies. The best results have been achieved with an oral bowel preparation such as neomycin-erythromycin. Metronidazole, combined with another agent to suppress facultative bacteria, has also produced excellent reduction in wound infections. While it is not firmly established that a systemic cephalosporin contributes to the proven good effects of an oral bowel preparation, there is evidence that the choice of the cephalosporin should be based, in part, on its activity against anaerobic bacteria.