Objective To explore the 28-day mortality risk of Klebsiella pneumoniae (KP) bloodstream infections (BSI) and its related influencing factors, thereby providing a scientific basis for the effective control of KP-BSI and improvement of patient prognosis.

Methods From January 2018 to December 2024, a retrospective review was conducted on hospitalized patients aged >18 years old treated for KP-BSI at a tertiary hospital in Hangzhou. Logistic and Cox regression analyses were performed to identify the epidemiological characteristics and the risk factors for the 28-day mortality associated with KP-BSI.

Results A total of 123 patients with KP-BSI were included in this study, comprising 64 cases infected with carbapenem-resistant Klebsiella pneumoniae (CRKP) and 59 cases infected with carbapenem-susceptible Klebsiella pneumoniae (CSKP). Compared with CSKP-BSI, patients with CRKP-BSI more frequently presented with chronic pulmonary disease (χ²=4.29, P=0.038), concomitant infections at other sites (χ²=10.90, P=0.001), and a higher frequency of invasive procedures prior to infection (central venous catheterization, mechanical ventilation, and indwelling urinary catheter), as well as glucocorticoid use, hemodialysis, and blood transfusion (all P<0.05). The 28-day mortality was significantly higher in BSI cases caused by CRKP compared to that caused by CSKP (37.50% vs 5.08%, P<0.001). Cox regression analyses revealed that carbapenem resistance (HR=6.67, 95%CI: 1.48‒30.08, P=0.014) and blood transfusion (HR=3.58, 95%CI: 1.15‒11.19, P=0.028) were risk factors for the 28-day mortality in KP-BSI, while removal of central venous catheters after infection (HR=0.24, 95%CI: 0.08‒0.67, P=0.006) was associated with a reduced risk for the 28-day mortality.

Conclusion Carbapenem resistance is associated with mortality outcomes in patients with KP-BSI. Strengthening infection control measures targeting the identified risk factors for CRKP-BSI may improve patient prognosis.