Short- and long-term outcomes in oliguric and non-oliguric acute kidney injury in intensive care: a retrospective, post hoc, bicentric study.

Background: Patients admitted to intensive care units (ICUs) frequently develop acute kidney injury (AKI). There is limited research comparing outcomes between oliguric and non-oliguric AKI in this population. This study aimed to investigate the short- and long-term outcomes in oliguric and non-oliguric AKI in intensive care patients; the specific outcomes assessed were mortality and major adverse kidney events. We hypothesised that short- and long-term outcomes would be poorer in oliguric compared with non-oliguric AKI in intensive care patients. Methods: This retrospective observational cohort study utilised prospectively collected data routinely gathered during patients' admission. All adult patients >16 years of age admitted to two large Scottish general adult ICUs were included. Patients with long-term kidney replacement therapy, prior transplantation and ICU readmission were excluded. Oliguria was defined as urine output <0.3 ml/kg/h for 24 h. Outcomes were assessed using Cox proportional hazards analyses; should its assumptions be violated, odds ratios at prespecified time points were undertaken. Results: Of the 2147 patients identified with Conclusion: Our study demonstrated that one-third of patients with AKI in intensive care developed oliguria using a standardised definition of oliguria. Oliguric AKI was found to be significantly associated with higher rates of mortality from in-critical care through 1-year post-discharge.