Impact of different types of organ failure on outcome in intensive care unit patients with acute kidney injury.

PURPOSE

The aim of this study was to explore the impact of different types of associated organ failure in patients with acute kidney injury (AKI).

MATERIALS AND METHODS

A retrospective analysis of 22 303 adult patients admitted to 22 intensive care units (ICUs) in the United Kingdom and Germany between 1989 and 1999 was done.

RESULTS

A total of 7898 patients (35.4%) had AKI. Intensive care unit mortality was 10.7% in patients without AKI, 20.1% in those with AKI I, 25.9% in those with AKI II, and 49.6% in those with AKI III. Intensive care unit mortality rose with increasing number of associated failed organs and preexisting chronic health problems. Respiratory failure was the most common associated organ failure, followed by cardiovascular failure. Less than 2% of the patients had associated neurologic failure alone, but the associated ICU mortality was higher than with single respiratory or cardiovascular failure. In AKI patients with 2 or more failed organ systems, combined cardiovascular and respiratory failure were most common. In multivariate analysis, associated neurologic or hepatic failure had the strongest impact on ICU outcome. There was little change in ICU mortality but a decrease in the standardized mortality ratio over time.

CONCLUSIONS

The prognosis of ICU patients with AKI depended on the total number and types of associated failed organ systems. Respiratory failure was the most common associated organ failure, but neurologic and hepatic failures were associated with the worst prognosis.