Sousa ALB, et al. - Researchers undertook this retrospective cohort analysis at a tertiary hospital, to determine the incidence, risk factors as well as prognosis of acute kidney injury (AKI) in a random sample comprised of nonagenarians hospitalized for two or more days. They studied data from 436 patients with a mean age of 93.5 ± 3.3 years, 74.3% were female; 76.4% needed intensive care unit (ICU). AKI incidence was estimated to be 45%. The identified independent predictors of AKI included length of hospital stay, ICU admission, vasopressors, and mechanical ventilation (MV). Overall in-hospital mortality was estimated to be 43.1%. Independent predictors of mortality revealed in multivariable analysis were: age, Charlson’s score, vasopressors, MV, and AKI, but not renal replacement therapy (RRT). Overall, hospitalized nonagenarians commonly developed AKI, which was related to a grave prognosis in these individuals, particularly in those who were critically ill. In this subgroup of patients, there was no influence of RRT on the fatal prognosis.