[Baseline characteristics of nonagenarians hospitalised due to acute kidney injury compared to other age groups]

Abstract

Background: The increase in life expectancy leads to higher hospitalisation rates in elderly patients. The aim of this work is to study the characteristics of the population over 90 years of age that are admitted due to acute kidney injury (AKI).

Material and methods: A cross-sectional study was conducted that included all patients admitted to hospital with AKI in the years 2013 and 2014. Epidemiological characteristics, comorbidity, medication and baseline analytical data were collected, and a comparison was made between patients with age over 90 years-old and the others.

Results: A total of 1733 patients were included, of whom 264 (15%) were over 90 years-old. A significantly higher proportion of these patients were women. The most frequent cause of AKI in patients older than 90 years was functional (81%) (p < 0.001 compared to other age groups). The main cause of hospital admission was infection. In the group of over 90 years of age, a higher prevalence was found for arterial hypertension (p = 0.005), chronic kidney disease (p = 0.014), congestive heart failure (p = 0.006), and cognitive impairment (p < 0.0001). The baseline glomerular filtration rate by CKD-EPI was lower in the group of patients older than 90 years (p < 0.0001). Patients under 90 years admitted to hospital due to AKI, had a higher prevalence of diabetes mellitus (p < 0.001), dyslipidaemia (p < 0.001), history of neoplasia (p < 0.001), and a higher Barthel index (p < 0.0001).

Conclusions: Nonagenarians admitted due to AKI have functional aetiology as the most common factor. These patients have a higher prevalence of hypertension, heart failure, chronic kidney disease, low functional status, and more cognitive impairment.

Keywords: Acute kidney injury; Epidemiology; Epidemiología; Fracaso renal agudo; Nonagenarians; Nonagenarios.