Effects of Antimicrobial Prophylaxis and Blood Stream Infections in Patients With Acute Liver Failure: A Retrospective Cohort Study

Background & Aims We investigated whether antimicrobial prophylaxis alters the incidence of bloodstream infection in patients with acute liver failure (ALF), and whether bloodstream infections affect overall mortality within 21 days after development of ALF. Methods We performed a retrospective cohort analysis of 1551 patients with ALF enrolled by the US Acute Liver Failure Study Group from January 1998 through November 2009. We analyzed data on infections in the first 7 days after admission and the effects of prophylaxis with antimicrobial drugs on the development of bloodstream infections and 21-day mortality. Results In our study population, 600 patients (39%) received antimicrobial prophylaxis and 226 patients (14.6%) developed at least 1 bloodstream infection. Exposure to antimicrobial drugs did not affect the proportion of patients who developed bloodstream infections (12.8% in patients with prophylaxis vs 15.7% in nonprophylaxed patients; P  = .12), but a greater percentage of patients who received prophylaxis received liver transplants (28% vs 22%; P  = .01). After adjusting for confounding factors, overall mortality within 21 days was associated independently with age (odds ratio [OR], 1.014), Model for End-stage Liver Disease score at admission (OR, 1.078), and vasopressor administration at admission (OR, 2.499). Low grade of coma (OR, 0.47) and liver transplantation (OR, 0.101) reduced mortality. Although bloodstream infection was associated significantly with 21-day mortality ( P  = .004), an interaction between bloodstream infection and etiology was detected: blood stream infection affected mortality to a greater extent in nonacetaminophen ALF patients (OR, 2.03) than in acetaminophen ALF patients (OR, 1.14). Conclusions Based on a large, observational study, antimicrobial prophylaxis does not reduce the incidence of bloodstream infection or mortality within 21 days of ALF. However, bloodstream infections were associated with increased 21-day mortality in patients with ALF—to a greater extent in patients without than with acetaminophen-associated ALF. Our findings do not support the routine use of antimicrobial prophylaxis in patients with ALF.