ABSTRACT
Objective:To investigate the predictive value of Pitt bacteremia score (PBS) on 28-day mortality of patients with extensively drug-resistant Klebsiella pneumoniae (XDR-KP) bloodstream infection.Methods:A retrospective cohort study was conducted to analyze the clinical characteristics of patients with XDR-KP bloodstream infection admitted to the Emergency Intensive Care Unit of Nanjing Drum Tower Hospital from January, 2018, to December, 2021. The patients were divided into the survival and non-survival groups according to the 28-day survival. Multivariate logistic regression analysis was performed to determine the risk factors of 28-day mortality of the patients. Receiver operating curve (ROC) curve was drawn to analyze the predictive value of PBS in 28-day mortality of patients with XDR-KP bloodstream infection. The correlations between PBS, and acute physiology and chronic health evaluation II (APACHE II) and sequential organ failure (SOFA) assessment were performed using Pearson correlation coefficient. The optimal cut-off value of PBS score was used as the boundary point to group the differences between APACHE II and SOFA scores in different groups. Kaplan-Meier method was used to analyze the prognosis of patients with XDR-KP bloodstream infection.Results:A total of 118 patients (82 males and 36 females) with XDR-KP bloodstream infection, aged (65.98±15.16) years, were included in this study. The 28-day mortality was 61.02%. The PBS was significant higher in the non-survival group than in the survival group [(5.68±1.86) vs. (2.48±1.02), P=0.011]. Multivariate logistic regression analysis showed that PBS ( OR=4.940, 95% CI: 2.720-8.968, P=0.008), APACHE II score ( OR=1.630, 95% CI: 1.361-1.952, P=0.010) and SOFA score ( OR=1.879, 95% CI: 1.451-2.422, P=0.009) were independently risk factors of 28-day mortality of patients with XDR-KP bloodstream infection. The area under the ROC curve of the PBS predicting 28-day mortality was 0.970 (95% CI: 0.945-0.995, P<0.001), and the optimal cut-of value was 3.5. In addition, PBS was significantly associated with APACHE II score ( r=0.916, P<0.001) and SOFA score ( r=0.829, P<0.001). Moreover, Kaplan-Meier analysis showed that the 28-day survival rate of patients with PBS <3.5 was significantly higher than that of patients with PBS >3.5 ( P=0.001). Conclusions:PBS is a significant, independent predictor of 28-day mortality in patients with XDR-KP bloodstream infection.