Increased incidence of postoperative infections during prophylaxis with cephalothin compared to doxycycline in intestinal surgery.

The antibiotics used for prophylaxis during surgery may influence the rate of surgical site infections. Tetracyclines are attractive having a long half-life and few side effects when used in a single dose regimen. We studied the rate of surgical site infections during changing regimens of antibiotic prophylaxis in medium and major size surgery. Prospective registration of surgical site infection following intestinal resections and hysterectomies was performed. Possible confounding procedure and patient related factors were registered. The study included 1541 procedures and 1489 controls. The registration included time periods when the regimen was changed from doxycycline to cephalothin and back again. The SSI in the colorectal department increased from 19% to 30% (p=0.002) when doxycycline was substituted with cephalothin and decreased to 17% when we changed back to doxycycline (p=0.005). In the gynaecology department the surgical site infection rate did not increase significantly. Subgroup analysis showed major changes in infections in rectal resections from 20% to 35% (p=0.02) and back to 12% (p=0.003). Doxycycline combined with metronidazole, is an attractive candidate for antibiotic prophylaxis in medium and major size intestinal surgery.