Effect of preoperative antibiotic regimen on development of infection after intestinal surgery: Prospective, randomized, double-blind study.

A prospective, randomized, double-blind study was performed to compare preoperative antibiotic preparation with neomycin (group 1), neomycin and tetracycline (group 2), and placebo (group 3) in patients undergoing elective intestinal surgery. The 196 patients were approximately equally distributed among the three study groups, which proved similar to each other in terms of age, sex, diagnosis, site of lesion, and operative procedure. There were significantly (P < 0.01) fewer patients with postoperative wound sepsis in the neomycin-tetracycline group (group 2) than in either of the two other groups. Postoperative wound infection rates in groups 1 and 3 were nearly identical. Most infections contained both aerobic and anaerobic bacteria. Eight of nine episodes of septicemia due to Bacteroides fragilis occurred in patients in groups 1 and 3.