Klebsiella pneumoniae infections in the intensive care unit: risk factors related to carbapenem resistance and mortality

Abstract

Introduction: Nosocomial infections caused by carbapenem-resistant Klebsiella pneumoniae in intensive care units (ICUs) are increasing worldwide. Morbidity and mortality rates are quite high in these infections due to limited treatment options and various risk factors. We determined the rate of carbapenem resistance, risk factors for carbapenem resistance, mortality rate, and risk factors associated with mortality in nosocomial infections in the adult ICU.

Methodology: We reviewed the medical records of nosocomial infected patients retrospectively, according to the surveillance diagnostic criteria established by the Centers for Diseases Control and Prevention. Bacterial identification and antibiotic susceptibility tests were performed on the Phoenix 100 system (Becton Dickinson, Sparks, MD, USA). During carbapenemase gene analysis, blaKPC, blaOXA-48, blaNDM-1, and blaIMP genes were investigated by polymerase chain reaction (PCR). Potential risk factors were statistically analyzed.

Results: Carbapenem resistance was detected in 52/76 of these patients (68.4%). The OXA-48 gene was present in all isolates, and the combination of OXA-48 and NDM-1 was found in 40.4% isolates. The overall mortality rate was 59.2% (45/76). Presence of malignancy; intubation; antibiotic use in the last 3 months; and quinolone, glycopeptide, carbapenem, and antifungal use were determined as risk factors for the development of carbapenem-resistant K. pneumoniae. Mechanical ventilation, presence of carbapenemase and pan-resistant status, and glycopeptide use were independent risk factors for mortality.

Conclusions: The data obtained in this study will guide the control measures for this infection and the rational use of antibiotics, and will contribute to the decrease in mortality rates.