Clinical characteristics and outcomes of patients with extended-spectrum β-lactamase-producing bacteremias in the emergency department.

Extended-spectrum β-lactamase (ESBL)-producing bacteria have been spreading from hospitals to communities. Despite this, there are limited emergency department (ED) patient-based studies about these bacteremias. A retrospective matched case-control study with a ratio of 1:3 was conducted at a university hospital. The case group consisted of patients aged >16 years with ESBL-producing bacteremias in the ED. Patients matched for age and sex with non-ESBL-producing bacteremias were sampled as the control group. Finally, 64 episodes of ESBL-producing Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis bacteremias were included in our study. The median age of case patients was 71 years, and 29 (45.3%) were males. The most common type of infection was urinary tract infection (71.9%), followed by intra-abdominal infection (12.5%). Inappropriate empirical antibiotics therapy was prescribed in 87.5% of case patients, which was significantly higher than the control group (13.0%; p < 0.001). Patients with inappropriate empirical antibiotics had a significantly longer hospital stay than those with appropriate empirical antibiotics (p < 0.001). Multivariate analysis showed that hospital-acquired infection, urinary catheterization, and previous antibiotics use were independent risk factors for the acquisition of ESBL-producing bacteremia. The 28-day mortality rate of case patients was 18.8%. Whether they received appropriate empirical antibiotics treatment or not, there was no statistical difference in the mortality of patients with ESBL-producing bacteremias (p = 0.167). To face these emerging multidrug-resistant bacteria and to guide the empirical antibiotics therapy, it is crucial for emergency physicians to recognize the characteristics and risk factors for ESBL-producing organisms.