Carbapenemase Production is Not Associated with Increased Mortality in Carbapenem-Nonsusceptible Enterobacteriaceae (CNSE) Bacteremia Patients: A Retrospective Study

Objectives: The aims of this study were to identify whether underlying carbapenem-nonsusceptible Enterobacteriaceae (CNSE) resistance mechanism was associated with clinical outcomes, and to evaluate risk factors for 7-day and 28-day mortality in patients with CNSE bacteremia Material and methods: A retrospective cohort study was conducted at a 2108-bed tertiary medical center. All medical charts of adult patients with carbapenem-resistant Enterobacteriaceae bacteremia from January 2013 to December 2018 were reviewed and included. The PCR techniques was used to screen the bacterial isolates collected for the presence of carbapenemase genes. Results: Of 99 patients with CNSE bacteremia, 13 (13.1%) were infected with carbapenemase-producing CNSE (CP-CNSE), and 86 (86.9%) with non-CP-CNSE. Risk factors for seven-day mortality in CNSE bacteremia included failure to prescribe at least one active antibiotic within three days of culture availability, respiratory failure after onset of bloodstream infection (BSI), steroid use <= 3 days prior to onset of BSI, septic shock at time of BSI, and underlying hematologic malignancies. Risk factors for twenty-eight mortality included failure to prescribe at least one active antibiotic within three days of culture availability, respiratory failure post BSI, septic shock at time of BSI, and use of mechanical ventilation at the time of BSI. Carbapenemase production and patient age did not affect 7-day or 28-day mortality. Conclusions: The results of this study indicate that prescribing at least one active antibiotic post culture availability reduces mortality in those with CNSE bacteremia. Carbapenemase production is not a risk factor for mortality in those with CNSE bacteremia. Copyright (c) 2022, Taiwan Society of Geriatric Emergency & Critical Care Medicine.