Gram classification of positive blood cultures is associated with mortality outcomes in septic acute kidney injury requiring continuous renal replacement therapy

Abstract

Abstract Sepsis is one of the most common causes of AKI in ICU patients, accounting for 15–20% of renal replacement therapy prescriptions. Herein, we aimed to investigate how bacterial blood culture results before CRRT correlate with mortality outcomes in patients with septic AKI requiring CRRT. The enrolled patients were divided into culture-negative, gram-positive, and gram-negative. Since the use of empirical antibiotics can affect culture-positive determination, information on antibiotic use was collected in chronological order. The primary outcome was in-hospital mortality after the initiation of CRRT. A total of 874 septic AKI patients requiring CRRT were classified into three groups: culture-negative, gram-positive cocci, and gram-negative rods. Their in-hospital mortality rates were 79.1%, 75.7%, and 61.9%, respectively (P = 0.002). In univariable Cox survival analysis performed after matching propensity scores, the gram-negative rod group was still associated with an approximately 37% reduction in mortality compared to the culture-negative group. The survival benefit of the gram-negative rod group during and after CRRT remained consistent across all subgroups, showing any P for interactions greater than 0.05. Culture-positive of gram-negative rods before CRRT initiation determine subsequent better clinical outcomes, such as lower mortality in patients undergoing CRRT due to septic AKI.