Transient and persistent acute kidney injury in acute liver failure.

BACKGROUND: Acute Kidney Injury (AKI) is a very frequent complication in the Acute Liver Failure (ALF) population associated with negative outcomes. We aim to evaluate the impact of AKI duration on the outcomes of an ALF population.

METHODS: A 20-year retrospective analysis of ALF patients admitted to an Intensive Care Unit (ICU) was performed. Chronic liver failure, chronic kidney disease on renal replacement therapy, dialysis requirement within the week prior or an ICU stay of less than 48 h after AKI diagnosis, were exclusion criteria. AKI was defined according to the KDIGO criteria and classified into transient (< 48 h duration) or persistent (48 h duration).

RESULTS: A total of 51 patients were included in the analysis and most had AKI (66.7%). Persistent AKI patients (70.6%) presented more frequently with AKI at admission and a higher SOFA score than transient AKI and no AKI, p < 0.05. More severe AKI, sepsis, vasopressor support and mechanical ventilation were also more common (p < 0.05). Nineteen (55.9%) were classified as persistent AKI exclusively by serum creatinine and 15 (44.1%) by both serum creatinine and urine output criteria. Mean survival time at 30 days was 11.3 days for persistent AKI, 25.3 days for transient AKI and 27.0 days for no AKI, p = 0.01. Adjusted multivariate cox regression analysis showed that persistent AKI predicted in-hospital mortality but it lost significance when AKI severity was introduced in the model.

CONCLUSION: Persistent AKI was common in ALF patients and associated with more severe AKI, worst systemic complications and a higher 30-day mortality, compared to transient and no AKI patients.