Clinical and Epidemiological Characteristics of Carbapenem-resistant Klebsiella Pneumoniae Infections in a Tertiary Hospital in China

Background: The infections due to carbapenem-resistant Klebsiella pneumonia (CR-KP) have become an important problem and they are associated with a high mortality rate. The aim of the study is to evaluate the clinical and epidemiological characteristics of CR-KP. Methods: A retrospective cohort study has been made on all patients presenting with CR-KP infections. 615 patients with CR-KP humor infections diagnosed between January 2018 and December 2019 were identified. 135 patients who did not meet the requirements were excluded, and the remaining 480 patients were enrolled in the study. We have evaluated the mortality in 30 days from the first positive culture. Clinical characteristics, antimicrobial regimens, and outcomes of patients have been analyzed. Results: The CR-KP infections overall mortality was 37.3%, and bloodstream infections mortality was 66.2%. Survival analysis revealed that there were statistically significant differences between bloodstream infection and pulmonary and drainage fluid infection. The gender, wards, and endotracheal intubation or tracheotomy before positive culture did not differ between the non-survivor and survivor groups. Logistics regression analysis showed that hemopathy, age (>60 years), solid tumors, diabetes, septic shock, acute kidney injury and stroke were independent predictors associated with the 30-day mortality. Multivariate linear regression was performed in APACHE II score, SOFA score, lymphocyte absolute value (LYM) and survival time. Survival time was negatively correlated with APACHE II score and SOFA score, while positively correlated with LYM. In addition, ROC curves were also drawn for APACHE II score, SOFA score and LYM, with AUC of 0.825, 0.876 and 0.797, respectively. Finally, we investigated different antimicrobial regimens for CR-KP infections. Chi-square test showed that antimicrobial regimen combined carbapenems, tigecycline with polymyxin B was superior the one combined carbapenems with polymyxin B, and the difference had statistically significant. But there was not statistically significant difference between carbapenems plus tigecycline and carbapenems plus polymyxin B, and it seemed that polymyxin B and tigecycline have synergistic effect. Ceftazidime avibactam-based antimicrobial regimens also had no advantage over other therapeutic regimens. Conclusions: Our study confirmed there is a high mortality rate in CR-KP infections, especially in the bloodstream infections. The outcome is greatly influenced by the patients’ clinical conditions. Antimicrobial regimen combined carbapenems, tigecycline with polymyxin B might be a better choice. Funding Statement: Not applicable. Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: The study was approved by the Human Ethics Committee of the First Affiliated Hospital of Zhengzhou University.