Assessment of Mortality-Related Risk Factors and Effective Antimicrobial Regimens for Treatment of Bloodstream Infections Caused by Carbapenem-Resistant Enterobacterales

Abstract

Bloodstream infections (BSIs) attributable to carbapenem-resistant Enterobacterales (CRE-BSIs) are dangerous and a major cause of mortality in clinical settings. This study was therefore designed to define risk factors linked to 30-day mortality in CRE-BSI patients and to examine the relative efficacies of different antimicrobial treatment regimens in affected individuals. Data pertaining to 187 CRE-BSI cases from four teaching hospitals in China collected between January 2018 and December 2020 were retrospectively analyzed. For the 187 patients analyzed in this study, the 30-day mortality of CRE-BSI was 41.7% (78/187). Multivariate logistic regression analyses revealed that Pitt bacteremia score, immunocompromised status, meropenem MIC of ≥8 mg/liter,absence of source control of infection, and appropriate empirical therapy were independent predictors of CRE-BSI patient 30-day mortality. After controlling for potential confounding factors relative to ceftazidime-avibactam (CAZ-AVI) treatment, combination therapies including CAZ-AVI (odds ratio [OR], 1.287; 95% confidence interval [CI], 0.124 to 13.403; P = 0.833) were not related to any significant change in patient mortality risk, whereas the 30-day mortality risk was higher for patients administered other antimicrobial regimens (OR, 12.407; 95% CI, 1.684 to 31.430; P = 0.011). When patients were treated with antimicrobial regimens not containing CAZ-AVI, combination therapy (OR, 0.239; 95% CI, 0.077 to 0.741; P = 0.013) was related to a decreased 30-day mortality risk relative to monotherapy treatment. The mortality-related risk factors and relative antimicrobial regimen efficacy data demonstrated in this study may guide the management of CRE-BSI patients.

Keywords: antimicrobial; bloodstream infection; carbapenem-resistant Enterobacterales; mortality; risk factor.

FIG 1

Screening algorithm of patients with CRE-BSI. In all, 226 hospitalized patients had blood cultures positive for CRE, and a total of 187 eligible, unduplicated cases were recruited into this study.

FIG 2

Survival rates of CRE-BSI patients treated with various definitive therapies (cutoff at 30 days after BSI onset). The 30-day mortality of patients treated with definitive regimens containing CAZ-AVI was significantly lower than that of patients treated with regimens not containing CAZ-AVI after control for confounders.

FIG 3

Survival rates of CRE-BSI patients treated with monotherapy and combination therapy (cutoff at 30 days after BSI onset). (A) The 30-day mortality of patients treated with combination therapy containing CAZ-AVI was similar to that of patients treated with CAZ-AVI alone. (B) The 30-day mortality of patients treated with combination therapy not containing CAZ-AVI was significantly lower than that of patients treated with monotherapy.