The Effect of Acute Kidney Injury on Mortality in Geriatric Patients Followed Up in the Intensive Care Unit

Background: The number of geriatric patients in the intensive care unit (ICU) is increasing day by day in line with the increase in the population. The present study evaluated the relationship between the presence of acute kidney injury (AKI) and mortality in geriatric patients, who are increasingly seen in the ICU. Methods: This retrospective study was conducted in a tertiary-level ICU of a public hospital in Istanbul, Turkey. The data of 2154 patients aged 65 and over, who were followed up in the ICU between January 2013 and January 2020, were collected and digitally analyzed using Structured Query Language. Results: The patients were divided into two groups as 1286 (59.7%) who developed AKI and 868 (40.3%) who did not develop AKI. Patients with AKI stay in the ICU longer than patients who did not develop AKI (median 5.91 vs. 3.44 days, p < 0.05). ICU mortality was 46.2% in patients with AKI and 25.8% in patients without AKI (p < 0.001). All stages of AKI were found to increase mortality (p < 0.05). The probability of mortality in patients above 85 years of age who developed AKI was 1.7 times higher compared to that of geriatric patients who developed AKI younger than 75 years (OR: 1.749; 95% CI: 1.099-2.785). While the increase in sequential organ failure assessment score, ventilator workload and lactate level, need for dialysis, and development of pressure sores was associated with increased mortality in geriatric patients with AKI, an increase in body mass index was associated with a decrease in mortality (OR: 0.961; 95% CI: 0.929-0.995). Conclusion: AKI is associated with ICU mortality in geriatric patients and it increases morbidity.