Antimicrobial prophylaxis of gastrointestinal surgical procedures and treatment of intraabdominal infections.

Antibiotic prophylaxis and treatment regimens ideally are selected on the basis of efficacy, safety, and cost. This review evaluates current, selected literature on antibiotic prophylaxis for colorectal surgery, presumptive antibiotic administration following penetrating abdominal trauma, and treatment of intraabdominal infections. Single-drug regimens with the newer, broad-spectrum agents are assessed and compared with combination regimens; specific regimens are recommended. Colorectal procedures require an antimicrobial agent with activity against both aerobes and anaerobes. Patients undergoing elective colorectal procedures can be adequately protected with an orally administered three-dose regimen of neomycin/erythromycin. Parenteral antibiotic administration is generally not necessary, but, cefoxitin is recommended for nonelective colorectal surgery. The risk of potential infectious complications following penetrating abdominal trauma without colonic perforation is less than with colonic perforation; however, antibiotic therapy that includes activity against aerobes and anaerobes is recommended for all types of penetrating abdominal trauma. Although cephalothin, cefamandole, or cefoxitin alone may be used in abdominal trauma without perforation of the colon, only cefoxitin is recommended as a single-drug alternative to the standard clindamycin/gentamicin regimen in trauma with colonic perforation. Single-drug therapy with cefoxitin or moxalactam can be used successfully as alternatives to the standard regimens of clindamycin/gentamicin or metronidazole/gentamicin in many patients with intraabdominal sepsis. Single-drug regimens reduce the risk of developing adverse effects and are cost-effective. However, if resistant organisms are suspected, or if the patient has been hospitalized for a prolonged period or has multiple organ failure, it may be necessary to supplement cefoxitin therapy with an antibiotic that will enhance coverage against gram-negative aerobes.