New advances in the use of antimicrobial agents in surgery: intra-abdominal infections

Advances in both technical methods and antimicrobial therapy have significantly reduced morbidity and mortality for secondary (enterogenous) or community-acquired intra-abdominal infections. Presumptive antimicrobial therapy for most community-acquired intra-abdominal infection can be safely initiated with a single broad-spectrum antimicrobial effective against the expected Enterobacteriaceae and anaerobic flora. Beta-lactams and carbapenems are effective against gram-negative rods and anaerobes, achieve therapeutic levels rapidly, and have low toxicity in the absence of penicillin allergy. Second generation cephalosporins (e.g. cefoxitin and cefotetan) remain useful in surgical prophylaxis and treatment of mild community-acquired pneumonia, but limitations in their spectra and antimicrobial resistance restrict their utility in more serious infections. The fourth generation cephalosporins are also effective, but should be combined with other antimicrobials such as metronidazole for adequate anaerobic coverage. Preliminary data on new fluoroquinolones are scant, but promising results were obtained in one clinical trial. We predict the current trend toward the use of broad-spectrum single agent antimicrobials for therapy of intra-abdominal infection will continue.