Prognostic value of acute kidney injury in patients with community-acquired pneumonia

Abstract

To investigate the incidence, severity, and prognostic value of acute kidney injury (AKI) in patients with community-acquired pneumonia (CAP). A total of 293 CAP patients (185 men and 108 women; mean age 54.3±17.1 years) were examined. AKI was diagnosed and classified in accordance with the 2012 KDIGO guidelines. On admission, the serum concentration of creatinine averaged 104.5±73.3 µmol/l. AKI was diagnosed in 83 (28.3%) patients with CAP. Hospital-acquired AKI was found in 25 (8.5%) patients, which amounted to 30.1% of all the AKI cases. The disease severity according to both the CURB-65 scale and the CRB-65 scale, which neglect blood urea nitrogen concentrations, was higher than that in patients with CAP associated with AKI (1.4±1.0 versus 0.4±0.6 scores; respectively; р<0.0001 and 0.8±0.7 versus 0.3±0.5 scores, respectively р<0.0001). The disease ended in a fatal outcome in 16 (5.5%) patients. The mortality in the presence of AKI was higher: 9 (10.1%) patients died in the AKI-complicated CAP group; that in the absence of AKI was 7 (5.2%; χ(2)=4.78; р=0.03), the odds ratio for death in the patients with CAP associated with AKI was 3.4; 95% confidence interval, 2.27 to 17.46. Multivariate logistic regression analysis revealed that the occurrence of AKI was independently influenced by age (р<0.001), systolic and diastolic blood pressures (p=0.01 and p=0.01, respectively), and a history of urinary tract diseases (p=0.04) and diabetes mellitus (p<0.001). AKI complicates CAP in 28.3% of cases and increases mortality in patients with CAP. The predictors of AKI in CAP patients are old age, hemodynamic disorders, diabetes mellitus, and prior urinary tract diseases.