Antibiotics as an Adjunct to Source Control: Revised Surgical Infection Society Guidelines for Antimicrobial Therapy of Intra-abdominal Infections

• Antimicrobial therapy is an adjunct to primary source control procedures in treating patients with intra-abdominal infections. • Therapeutic antimicrobials (those given for longer than 24 h) are required only for patients with established intra-abdominal infections. Patients with limited exposure to contamination from a perforated viscus and those who have a removable focus of inflammation should be treated with prophylactic antimicrobials only (those given for less than 24 h). • Therapeutic antimicrobials for intra-abdominal infections should generally be limited to no more than 5–7 days. Ongoing clinical evidence of infection should prompt a search for a new or recurrent infection rather than arbitrary prolongation of antimicrobial therapy with new or different agents. • Antimicrobial regimens for intra-abdominal infections should cover common aerobic and anaerobic enteric flora. A number of different regimens are available, but the choice of antimicrobials for most patients with community-acquired infections should be dictated primarily by considerations of cost, convenience, and potential toxicity. • Patients at high risk for therapeutic failure include those with preexisting physiological compromise and those with difficult-to-treat organisms, which many times have been acquired in the hospital. Antimicrobial therapy may need to be intensified in some of these patients to cover resistant Gram-negative aerobic organisms, enterococci, and yeast.