Prophylactic antibiotics in colon surgery.

One hundred twenty-three patients undergoing elective colon surgery were prospectively and randomly assigned to receive either three 1-g perioperative doses of intramuscular cephaloridine or three 1-g preoperative doses of both oral erythromycin base and neomycin sulfate. All patients had their bowels thoroughly cleansed mechanically. The groups were comparable in age and nutritional status. Eight wound infections occurred in the 65 patients receiving cephaloridine (12.3%) v one in the 58 receiving erythromycin and neomycin (1.7%). The difference was statistically significant. Eight of nine infected patients had only wound infections; the majority of cultures yielded Bacteroides fragilis. Serum and tissue antimicrobial concentrations were determined in the first 70 randomized patients at operation. Mean (+/- SD) cephaloridine levels were 14.7 +/- 10.2 and 10.5 +/- 10.0 mg/L in serum and tissue, respectively, compared with 1.98 +/- 1.58 and 0.699 +/- 1.146 mg/L for serum and tissue erythromycin levels.