SELECTIVE DECONTAMINATION OF THE COLON BEFORE ELECTIVE COLORECTAL SURGERY

The controversy over the route of administration of antibiotic prophyl axis in patients undergoing elective colorectal operations persists fo r oral, parenteral, and a combination of the two routes. The oral anti biotics commonly administered for colorectal prophylaxis, neomycin and eythromycin base, are not absorbed in the gastrointestinal tract (GIT ). However, the 4-fluoroquinolones are absorbed in the upper GIT and a re excreted in part by the colonic mucosa. Their action is then to rem ove, or severely depress, the gram-negative aerobic bacilli leaving th e anaerobic flora unaffected. This action is the principle of selectiv e decontamination. We have assessed the efficacy of oral ciprofloxacin in a prospective randomized clinical trial in which all patients rece ived piperacillin 4 g IV as single-dose parenteral prophylaxis. A grou p of 327 evaluable patients were randomized to receive ciprofloxacin 5 00 mg b.i.d. with the preoperative cathartic (group OA, n = 159) or no oral antibiotic (group NOA, n = 168). Postoperative wound infection o ccurred in 18 (11.3%) patients in group OA and 39 (23.2%) patients in group NOA (chi(2) = 7.2, p = 0.007). Operation-related infection of an y type occurred in 23 (14.5%) patients in group OA compared with 55 (3 2.7%) in group NOA (chi(2) = 14.0, p = 0.0002). The median postoperati ve hospital stay was 11 days (interquartile range 4.5 days) for group OA and 12 days (interquartile range 8 days) for group NOA (Mann Whitne y U test, p = 0.005). Ignoring the treatment group, the median postope rative hospital stay was 17 days (interquartile range 10 days) for inf ected patients and 11 days (interquartile range 4 days) for those not infected. We conclude that the administration of ciprofloxacin 500 mg b.i.d. with the preoperative cathartic significantly reduces the incid ence of infection after elective colorectal operations and should form part of the preoperative preparation for such operations.