RIFLE and Acute Kidney Injury Network classifications predict mortality in leptospirosis-associated acute kidney injury.

Aim:  Acute kidney injury (AKI) is a common complication in leptospirosis. The aim of this study is to investigate the association between RIFLE and AKIN classifications with mortality in leptospirosis-associated AKI. Methods:  A retrospective study was conducted in patients with leptospirosis admitted to tertiary hospitals in Brazil. The association between RIFLE and AKIN classifications with mortality was investigated. Univariate and multivariate analysis was performed to investigate risk factors for death. Results:  A total of 287 patients were included, with an average age of 37 ± 16 years, and 80.8% were male. Overall mortality was 13%. There was a significant association between these classifications and death. Among non-survivors, 86% were in the class ‘failure’ and AKIN 3. Increased mortality was observed according to the worse classifications: ‘risk’ (R; 2%), ‘injury’ (I; 8%) and ‘failure’ (F; 23%), as well as in AKIN 1 (2%), AKIN 2 (8%) and AKIN 3 (23%) (P < 0.0001). The worst classifications were significantly associated with death: RIFLE F (odds ratio = 11.6, P = 0.018) and AKIN 3 (odds ratio = 12.8, P = 0.013). Receiver–operator curve for patients with AKI showed high areas under the curve (0.71, 95% confidence interval = 0.67–0.74) for both RIFLE and AKIN classifications in determining the sensitivity for mortality. Conclusion:  There is a significant association between RIFLE and AKIN classifications with mortality in patients with leptospirosis. Initiation of dialysis in patients with RIFLE F and AKIN 3 should always be considered.