ANTIMICROBIAL PROPHYLAXIS IN COLORECTAL SURGERY - A SYSTEMATIC REVIEWOF RANDOMIZED CONTROLLED TRIALS

Background A systematic review was carried out to assess the relative efficacy of antimicrobial prophylaxis for the prevention of postoperat ive wound infection in patients undergoing colorectal surgery. Methods MEDLINE, EMBASE, the Cochrane Trials Register and the references cite d in retrieved studies were searched to identify relevant trials publi shed between 1984 and 1995. Results Some 147 relevant trials were iden tified. The quality of trials has improved over the past 12 years. The results confirm that the use of antimicrobial prophylaxis is effectiv e for the prevention of surgical wound infection after colorectal surg ery. There was no significant difference in the rate of surgical wound infections between many different regimens. However, certain regimens appear to be inadequate (e.g. metronidazole alone, doxycycline alone, piperacillin alone, oral neomycin plus erythromycin on the day before operation). A single dose administered immediately before the operati on (or short-term use) is as effective as long-term postoperative anti microbial prophylaxis (odds ratio 1.17 (95 per cent confidence interva l (c.i.) 0.90-1.53)). There is no convincing evidence to suggest that the new-generation cephalosporins are more effective than first-genera tion cephalosporins (odds ratio 1.07 (95 per cent c.i. 0.54-2.12)). Co nclusion Antibiotics selected for prophylaxis in colorectal surgery sh ould be active against both aerobic and anaerobic bacteria. Administra tion should be timed to make sure that the tissue concentration of ant ibiotics around the wound area is sufficiently high when bacterial con tamination occurs. Guidelines should be developed locally in order to achieve a more cost-effective use of antimicrobial prophylaxis in colo rectal surgery.