Summary

Background:

Acute kidney injury (AKI) is a risk factor for morbidity and mortality during critical illness especially in very old patients admitted to intensive care units.

Objectives:

To identify prognostic markers for AKI patients.

Methods:

This single-center retrospective study was based on a patient registry of a medical intensive care unit. Hospital records of patients aged 80 years or older admitted between 2005 and 2015 were examined. Patients who developed AKI according to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines within 4 days of admission were included in this study.

Results:

The study comprised 96 patients with AKI and 81 age- and sex-matched controls without AKI. Mean acute physiology and chronic health evaluation (APACHE) II score was 30 with an ICU mortality of 27% in very old patients with AKI. The odds ratio of hospital mortality for these patients was 5.02 compared to controls (49% vs. 16%). APACHE II score and fluid balance in the first 2 days of ICU admission were the strongest predictors of ICU mortality with an area under the receiver operating characteristic of 0.76. Of the 47 patients with AKI who survived hospital admission, 30 were discharged home.

Conclusions:

Mortality was increased in very old ICU patients with AKI. Among survivors, two-thirds returned home.