Background

There has been little in the way of study of nonagenarians with acute kidney injury (AKI, defined in lines with KDIGO guidelines), but the rise in their life expectancy makes further study of this population necessary. The aim of this study is to assess mortality in nonagenarians with AKI during hospitalization.

Methods

In this retrospective study, patients with AKI during hospitalization between 2013-2014 were included. At baseline, epidemiological variables, comorbidities and treatments were collected. Analytics and mortality were studied during hospitalisation. Univariate analysis was carried out to evaluate mortality-associated variables. A logistic regression analysis was carried out to demonstrate independent predictors for mortality.

Results

Two hundred and sixty-four nonagenarian patients were included. Mean age was 93±3 years, 73 (27.7 %) of whom were men. During hospitalization, 79 patients (29.9 %) died. Comorbidities related to mortality were history of heart failure (p = 0.018), diastolic dysfunction (p < 0.042) and higher dependence according to the modified Barthel index (p = 0.003). The clinical variables related to mortality at hospital admission were lower systolic (p = 0.016) and diastolic blood pressure (p = 0.013), higher white blood cell count (p = 0.003), greater severity of AKI (p = 0.003) and L- lactic (p = 0.005). In an adjusted multivariate analysis, history of heart failure (OR = 2.31, 95%CI: 1.07-5.00, p = 0.036), dependence according to the Barthel index (OR = 0.80, 95%CI: 0.67-0.97, p = 0.016) and L- lactic acid (OR = 1.31, 95%IC: 1.06-1.61, p = 0.005) were independent predictors of mortality.

Conclusion

Heart failure, dependence according to the Barthel index and L- lactic acid at admission are independent predictors of mortality in nonagenarians hospitalized with AKI.