In an open-label trial involving adults with complicated intra-abdominal infections at 23 centers in the U.S. and Canada, researchers have investigated whether fixed-duration antimicrobial therapy (4 days) after source control is as effective as the traditional strategy (antibiotic administration until 2 days after resolution of fever, leukocytosis, and ileus).
Patients were randomized in a 1:1 ratio to the fixed-duration (experimental) or the traditional-strategy (control) group, with therapy duration for the control group capped at 10 days. Follow-up lasted for 30 days after the initial source-control procedure and included assessment for infectious complications and all-cause mortality (the composite primary endpoint), as well as for use of antimicrobial therapy. A total of 517 patients completed 30-day follow-up. Most often, their infections originated in the colon or rectum; the source-control procedure was percutaneous in one third of each group.
The composite primary endpoint occurred in 22% of patients in each arm. The median duration of antimicrobial therapy was 4.0 days (interquartile range, 4.0–5.0) and 8.0 days (interquartile range, 5.0–10.0) in the experimental and control groups, respectively (absolute difference, –4.0 days; 95% confidence interval, –4.7 to –3.3). Nonadherance to protocol was common — 18.2% in the experimental group and 27.3% in the control group did not receive antibiotics for the specified duration (P=0.02)
The primary intervention is source control either percutaneously or via operative intervention. Following source control, though, it appears as if 4 days of appropriate antibiotics is probably sufficient. Unfortunately, this study had poor adherence to protocol for both arms making the conclusions inconclusive.
Sawyer RG et al. Trial of short-course antimicrobial therapy for intraabdominal infection. N Engl J Med 2015 May 21; 372:1996