Predictors of oliguric acute kidney injury in leptospirosis. A retrospective study on 196 consecutive patients

Abstract

Background: Acute kidney injury (AKI) occurs in 10 to 60% of patients with leptospirosis. The aim of this study is to investigate markers for oliguric AKI in leptospirosis.

Methods: A retrospective study was performed with 196 consecutive patients with leptospirosis-associated AKI. These patients were categorized into either oliguric or non-oliguric according to their urine output. Clinical and laboratory characteristics were compared between the two groups.

Results: Among these patients, 64 (32.6%) were oliguric and 132 (67.4%) nonoliguric. Markers for oliguria were age higher than 40 years (OR = 1.02, p = 0.04), hyponatremia (OR = 0.94, p = 0.03), elevated serum creatinine (OR = 1.11, p = 0.04), low arterial pH (OR = 1.0002, p = 0.01), high levels of AST (OR = 1.005, p = 0.01), crackles (OR = 3.83, p < 0.001) and direct bilirubin (OR = 1.03, p = 0.03). Elevated activated prothrombin time (OR = 0.97, p = 0.03) was a factor associated with nonoliguric AKI. Independent markers for oliguria were crackles (OR = 5.17, p = 0.0016) and direct bilirubin levels (OR = 1.051, p = 0.04). Mortality was significantly higher in oliguric than nonoliguric (27 vs. 8%, p < 0.001). Renal function at discharge was similar in oliguric and nonoliguric patients.

Conclusion: Age higher than 40 years, hyponatremia, elevated serum creatinine, low arterial pH, high levels of AST, crackles and direct bilirubin levels would be useful to early identify patients with oliguric AKI in leptospirosis.