Risk Factors for and Clinical Outcomes of Carbapenem-Resistant Klebsiella pneumoniae Nosocomial Infections: A Retrospective Study in a Tertiary Hospital in Beijing, China.

Purpose Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections have been increasingly reported worldwide. We aimed to identify the risk factors for nosocomial CRKP infections and assess the clinical outcomes. Patients and Methods We conducted a case-control study with data collected from January 2016 to December 2018 in China. Controls were selected at a ratio of 1:1 from patients with nosocomial carbapenem-susceptible Klebsiella pneumonia (CSKP) infections. Risk factors for nosocomial CRKP infections and clinical outcomes were assessed with univariate and multivariate analyses. Results A total of one hundred forty-two patients with CRKP infections and one hundred forty-two patients with CSKP infections were enrolled in this study. Multivariate analysis showed that exposure to antibiotics within 3 months prior to admission (odds ratio OR, 2.585; 95% confidence interval [CI], 1.425-4.691; P=0.002), exposure to carbapenems (OR, 2.532; 95% CI, 1.376-4.660; P=0.003), exposure to fluoroquinolones (OR, 3.309; 95% CI, 1.326-8.257; P=0.010), and the presence of a nasogastric tube (OR, 2.796; 95% CI, 1.369-5.712; P=0.005) were independent risk factors for CRKP infections. The 30-day mortality rate in the CRKP group was 19.7%, while the in-hospital mortality rate was 28.9%. In the CRKP group, a higher creatinine level (OR, 1.009; 95% CI, 1.002-1.016; P = 0.013), being in shock at the time of a positive culture (OR, 4.454; 95% CI, 1.374-14.443; P = 0.013), and co-infection with other resistant bacteria (OR, 4.799; 95% CI, 1.229-18.740; P = 0.024) were independent predictors of in-hospital mortality in patients with CRKP infections. Kaplan-Meier curves showed that the CRKP group had a shorter survival time than the CSKP group. Conclusion Nosocomial CRKP infection was associated with exposure to carbapenems and fluoroquinolones within 3 months prior to hospitalization and the presence of a nasogastric tube. Patients infected with CRKP had higher 30-day and in-hospital mortality rates. A higher creatinine level, shock and co-infection with other resistant bacteria were independent predictors of in-hospital mortality in patients with CRKP infections.