BACKGROUND & AIMS Third-generation cephalosporins (TGCs) are recommended as first-line antibiotics for treatment of spontaneous bacterial peritonitis (SBP). However, antibiotics against multidrug-resistant organisms (such as carbapenems) might be necessary. We aimed to evaluate whether carbapenems are superior to TGC for treatment of SBP.

METHODS We performed a retrospective study of 865 consecutive patients with a first presentation of SBP (275 culture positive; 103 with TGC-resistant bacterial infections) treated at 7 referral centers in Korea, from September 2013 through January 2018. The primary outcome was in-hospital mortality. We made all comparisons using data from patients whose baseline characteristics were balanced by inverse probability of treatment weighting.

RESULTS Of patients who initially received empirical treatment with antibiotics, 95 (11.0%) received carbapenems and 655 (75.7%) received TGCs. Among the entire study cohort, there was no significant difference in in-hospital mortality between the carbapenem (25.8%) and TGC (25.3%) groups (adjusted odds ratio [aOR], 0.97; 95% CI, 0.85-1.11; P = .66). In the subgroup of patients with high chronic liver failure-sequential organ failure assessment (CLIF-SOFA) scores (score of 7 or greater, n = 314), carbapenem treatment was associated with lower in-hospital mortality (23.1%) than in the TGC group (38.8%) (aOR, 0.84; 95% CI, 0.75-0.94; P=.002). In contrast, among patients with lower CLIF-SOFA scores (n = 436), in-hospital mortality did not differ significantly between the carbapenem group (24.7%) and the TGC group (16.0%) (aOR, 1.06; 95% CI, 0.85-1.32; P = .58).

CONCLUSIONS For patients with a first presentation of SBP, empirical treatment with carbapenem does not reduce in-hospital mortality compared to treatment with TGCs. However, among critically ill patients (CLIF-SOFA scores ≥7), empirical carbapenem treatment was significantly associated with lower in-hospital mortality than TGCs.