SAN ANTONIO – Four days of antibiotics is sufficient and safe for percutaneous drainage of complicated intra-abdominal infections in non-ICU patients, according to investigators from the University of Miami.
“There was no difference in outcome between a shorter and longer duration of antimicrobial therapy in those with percutaneously drained source control of a CIAI [complicated intra-abdominal infection]. Percutaneously drained intra-abdominal infections do not require longer duration of antimicrobial therapy,” they concluded.
The findings are from a posthoc subgroup analysis of the influential STOP-IT [Study to Optimize Peritoneal Infection Therapy] trial, which found that in CIAI patients with adequate source control, “the outcomes after fixed-duration antibiotic therapy (approximately 4 days) were similar to those after a longer course of antibiotics (approximately 7 days) that extended until after the resolution of physiological abnormalities” (N Engl J Med. 2015 May 21;372:1996-2005).
STOP-IT lumped together patients who had both surgical and percutaneous source control. Unlike surgical clean out, percutaneous drainage usually leaves behind some infection; the Miami investigators wanted to see if that made a difference in the safety and effectiveness of short-course antibiotics. Seventy-two patients received a 4-day course and 57 were on antibiotics until 2 days after their symptoms resolved, which usually worked out to about 7 days.
There were no statistically significant differences between the groups in the rates of recurrent intra-abdominal infection (9.7% in the 4-day group vs. 10.5% in the longer-duration group, P = 1.00), Clostridium difficile infection (0% vs. 1.8%; P = .442), and hospital days (a mean of 4 days in both). The only difference was that the time to recurrent infection was shorter in the 4-day group (12.7 vs. 21.3 days; P = .015). None of the patients died.
The big caveat with STOP-IT and the posthoc analysis is that the patients weren’t very sick. Their mean APACHE [Acute Physiology and Chronic Health Evaluation] score was 10, and fevers and leukocytosis were generally mild. Patients without adequate source control, patients with open abdomens, and those likely to die within 72 hours were excluded.
“They were very different from our patients in the ICU with major complex intra-abdominal infections and septic shock and multiorgan dysfunction. To take STOP-IT or our analysis and say we are going to extrapolate that to our sickest patients and stop their antibiotics at 4 days is dangerous without further study. That’s the population everyone’s asking about now. We need a larger [randomized, controlled trial] in a much sicker population” to know how to handle the issue, said posthoc investigator Dr. Rishi Rattan, a critical care and trauma surgery fellow at the University of Miami.
The other big question, as raised by an audience member, and one at the other end of the spectrum is if antibiotics are needed at all after adequate source control, at least in some patients.
“We should look at that. I think we need to push the envelope and drill down even further to 48 and 24 hours, and study that versus 4 days,” Dr. Rattan said at the Eastern Association for the Surgery of Trauma scientific assembly.
Patients in STOP-IT were aged 16 years and older with either a temperature of at least 38º C, white blood cell counts of 11,000 cells/mm3 or higher, or peritonitis-induced gastrointestinal dysfunction. Baseline demographics, comorbidities, and illness severity were similar between treatment arms. Appendicitis was limited to about 10% of infections, so there was a diversity of infections and heterogeneity in the study population. Antibiotic selection was empiric, based on investigators’ institutions.
Based on STOP-IT, the University of Miami now usually limits antibiotics to 4 days after source control of CIAI in less-sick patients. The University was a STOP-IT site, which is why the posthoc team had access to the data.
The investigators have no disclosures.