Acute Kidney Injury in Elderly Population: A Prospective Observational Study

Background/Aims: Acute kidney injury (AKI) has been reported as a recognized condition among the elderly population; however, its clinical epidemiology is still poorly evaluated. We propose to evaluate the epidemiological profile of AKI in hospitalized elderly patients and the variables associated with renal replacement therapy (RRT) dependency at discharge after an episode of AKI. Methods: This prospective observational study enrolled 286 elderly patients (aged ≥60 years), who had a diagnosis of AKI and were admitted to a tertiary care hospital. Clinical data were analyzed, which included RRT indication, referral time to nephrologist support, standby period in the emergency care units (ECU) before a transfer to an intensive care unit, staff criteria used to indicate palliative care, and the incidence of patients who stayed on chronic dialysis for at least 6 months after discharge. Results: The overall hospital mortality was 56.3%. Acute Kidney Injury Network (AKIN) 3 at the time of admission was significantly higher in patients who underwent RRT. Intrinsic AKI (p < 0.001), AKIN 3 (p < 0.001), RRT (p < 0.001), and increased length of stay in ECUs (p = 0.01) all had a significantly higher prevalence among non-survivors. On multivariate analysis, however, only renal aetiology (intrinsic AKI) was independently associated with mortality (OR 2.88; 95% CI [1.29–6.13]). Approximately 85% of the discharged patients (n = 125) were dialysis free and 36.4% of them who had a previous diagnosis of chronic kidney disease (CKD) upon admission had a worse renal function. Age, AKIN 3, RRT, prior history of CKD, diabetes mellitus, and the number of hemodialysis sessions showed to have an impact on dialysis dependence. Furthermore, 24 of 161 patients who had a dialysis indication were placed on palliative care. Conclusions: The severity of AKI and the need for RRT were risk factors for mortality and dependence on dialysis. Antecedents of CKD seem to be associated with a poor renal outcome following an AKI episode. Starting RRT had an impact on the clinical decision to enroll these patients into palliative care.