Risk Factors for Mortality in Patients with Klebsiella pneumoniae Carbapenemase-producing K. pneumoniae and Escherichia coli bacteremia

Background: Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales bacteremia is associated with significant mortality; however, no optimal antibiotic strategy is available. We aimed to evaluate the clinical outcomes according to the antibiotic regimens and identify risk factors for mortality in patients with KPC-producing K. pneumoniae and Escherichia coli bacteremia. Materials and Methods: This retrospective cohort study included all adult patients with monomicrobial bacteremia (KPC-producing K. pneumoniae or E. coli) between January 2011 and March 2021 at a 2,700-bed tertiary center. Results: Ninety-two patients were identified; 7 with E. coli bacteremia, and 85 with K. pneumoniae bacteremia. Thirty-day mortality was 38.0% (35/92). Non-survivors were more likely to have had nosocomial infection (88.6% vs. 63.2%, P = 0.01), high APACHE II scores (mean [interquartile range], 22.0 [14.0 -28.0] vs. 14.0 [11.0 -20.5], P <0.001), and septic shock (51.4% vs. 26.3%, P <0.001) and less likely to have been admitted to the surgical ward (5.7% vs. 22.8%, P = 0.04), undergone removal of eradicable foci (61.5% vs. 90.6%, P = 0.03), and received appropriate combination treatment (57.1% vs. 78.9%, P = 0.03) than survivors. No significant difference in mortality was observed according to combination regimens including colistin, aminoglycoside, and tigecycline. In multivariable analysis, high APACHE II scores (adjusted odds ratio [aOR], 1.14; 95% confidence interval [CI], 1.06 -1.23, P <0.001), and appropriate definitive treatment (aOR, 0.25; CI, 0.08 -0.74, P = 0.01) were independent risk factors for mortality. Conclusion: High APACHE II scores and not receiving appropriate definitive treatment were associated with 30-day mortality. Mortality did not significantly differ according to combination regimens with conventional drugs such as aminoglycoside and colistin.

Automated summary

This study identified that patients with KPC-producing K. pneumoniae and Escherichia coli bacteremia had a higher 30-day mortality rate, which may be related to high APACHE II scores and not receiving appropriate definitive treatment. Combination regimens with conventional drugs such as colistin, aminoglycoside, and tigecycline did not significantly affect mortality outcomes.