[Risk factors for developing acute kidney injury in elderly patients].

Background: The incidence of acute kidney injury in hospitalized elderly is a frequent event that makes them prone to complications and can even lead to death. Therefore, identifying risk factors for developing acute kidney injury becomes a priority in the process of care of the elderly.

Objective: To identify the main risk factors for acute kidney injury in hospitalized elderly and, on the basis of those risk factors, calculate the probability of presentation.

Methods: Case-control study nested in a cohort, which included patients of 60 years or older, admitted to the Internal Medicine service at an institution of social security in Querétaro, Mexico. Patients with acute kidney injury were identified as cases and patients without acute kidney injury were included in the control group. Acute kidney injury was diagnosed when there was an increased creatinine level ≥ 0.3 mg/dL (≥ 26.4 mmol/L) in a period < 48 hours.

Results: Hypovolemia and infection were identified as risk factors for acute kidney injury and they were included into the model of multiple logistic regression (y = 1,111 + 1,063 [infection] + 1.422 [hypovolemia]), (p = 0.002). The highest probability of having acute kidney injury was 80%.

Conclusions: Two factors for acute kidney injury and a prediction model were identified.