Effectiveness of single dose prophylaxis with cefotaxime and metronidazole compared with three doses of cefotaxime alone in elective colorectal surgery.

OBJECTIVE: To compare three doses of cefotaxime alone with a single dose of cefotaxime and metronidazole for the prophylaxis of infection after elective colorectal operations. DESIGN: Prospective random control trial. SETTING: Hillerod and Frederiksberg Hospitals, Copenhagen, Denmark. SUBJECTS: 660 consecutive patients who were to undergo elective colorectal operations during a 48 month period (January 1987-January 1991); 93 (14%) were withdrawn after randomisation leaving 567 for assessment. INTERVENTIONS: Mechanical bowel preparation, and then either cefotaxime (Claforan) 2 g intravenously at induction of anaestesia and 3 and 9 hours later (n = 280) or a single dose of cefotaxime 2 g plus metronidazole (Flagyl) 1.5 g intravenously at induction of anaestesia (n = 287). RESULTS: 44 patients in the cefotaxime group developed wound infection (16%) compared with 19 (7%) in the combined group (p < 0.001). In the cefotaxime group 22 of the 241 patients who had an anastomosis developed leaks (9%) compared with 8 of the 239 in the cefotaxime/metronidazole group (3%). There were no differences in the incidence of intra-abdominal abscesses or burst abdomens. The most common organisms isolated from wounds were Escherichia coli and Bacteriodes fragilis. CONCLUSION: One dose of cefotaxime and metronidazole is active against a wide range of organisms and resulted in significantly fewer wound infections than three doses of cefotaxime alone.