Current status of antibiotic prophylaxis in surgical patients

In clean-contaminated surgical procedures with predictable wound contamination, administration of prophylactic antibiotics is rational. In clean surgical procedures, where infection of a prosthetic device or prosthetic material will likely lead to disastrous clinical results, a rational basis exists for prophylactic antibiotics. First generation cephalosporins have proved effective in well-designed controlled studies for many surgical procedures. There is no evidence that one first generation cephalosporin is superior to another; similarly, there is no evidence of superiority of a second or third generation cephalosporin in surgical situations where a first generation cephalosporin has proved effective. The greatest of prophylaxis accrues in situations where the drugs are effective, inexpensive, and need only be given for a short period. In surgical situations, the presence of adequate tissue concentrations of active antibiotic during the operation is the critical factor in effective prophylaxis. Usually, s single preoperative dose is all that is needed. Prolonged prophylaxis only increases expense and promotes the selection of resistant organisms. Due to the length of the procedure, patients undergoing cardiac prosthetic valve surgery are an exception and require repeat doses of prophylactic first generation cephalosporin every three to four hours. The prophylactic antibiotic regimens must be viewed as tentative because of the study design deficits outlined by Hirschmann and Inui and the inherent variability in infection rates after operation. Future studies may generate alternative recommendations. With superlative surgical technique, infection rates may be so low without antibiotics as to make antibiotic prophylaxis unnecessary, even in clean-contaminated surgery.