RESUMO
From 1983 until 1990 our standard antibiotic prophylaxis in colorectal surgery has been 80 mg gentamicin plus 500 mg metronidazole, both administered intravenously at the beginning of anesthesia, and then 80 mg gentamicin every 8 h for 3 days. In this time period, 718 patients undergoing elective colorectal surgery by abdominal approach were treated with this prophylactic procedure. The mean wound infection rate was 13.4% with no significant differences between years. In the present study, including 100 adult patients, intravenous gentamicin has been replaced by a single oral dose of 750 mg ciprofloxacin randomly administered 1, 2 or 3 h (+/- 30 min) before anesthesia. All other procedures remained unchanged including intravenous metronidazole. In order to correlate an eventual infection with the actual tissue concentrations during surgery, samples of colon, peritoneum, muscle, subcutaneous fat and skin were obtained from all patients and assayed by HPLC. In only 3 cases (3% of them casuistic) was a wound infection observed, 2 of minor importance and 1 case with wound dehiscence. This infection rate is significantly lower than 13.4% obtained with our previous standard regimen, and lower than the 9% wound infection rate considered to be the 'gold standard' for elective colon resections. The effective ciprofloxacin concentrations in tissues were usually notably higher than the MICs of the pathogens commonly observed in surgical infections of colorectal surgery. By far the highest ciprofloxacin concentrations were observed in colon tissue which may explain the absence of anastomotic dehiscence or peritoneal sepsis in our series.(ABSTRACT TRUNCATED AT 250 WORDS)
