[RIFLE Classification: prospective analysis of the association with mortality in critical ill patients]

The recent RIFLE classification defines three degrees for severity of acute kidney injury (AKI): RISK, INJURY and FAILURE and was associated with mortality according to the grading of the severity of AKI, but little valued at prospective studies.

To evaluate the association of RIFLE score with mortality in critically ill patients and compare the clinical characteristics between them.

An observational prospective cohort study of 200 patients admitted to the ICU, from July/2010 to July/2011. Patients included were older than 18 years, had for more than 24 hours in the ICU and signed the Term of informed consent.

The frequence of AKI in the ICU was 47% (n = 95), the maximum RIFLE: Risk 4.5% (n = 09), Injury 11%(n = 23) and Failure 31.5% (n = 63). The ICU mortality was 25.5% (n = 51). The RIFLE categorized into class RIFLEmaximum class Injury + Failure had a higher mortality compared to the subgroup categorized No LRA + AKI Risk class (53.3% vs. 4.4%) and the greater the relative risk of the patient so classified: RR = 3.3 (95%: 2.5 to 4.4) p < 0.001. RIFLE categorized as RIFLEmaximum class Injury + Failure and SOFAmaximum score, independently associated with ICU mortality after adjustment for multiple variables.

The severity of AKI according to RIFLE criteria was a risk marker for mortality in this population. The LRA group class Injury + Failure was associated with increased mortality when compared to the subgroup Without AKI + AKI that remained in Risk class even after adjustments for multiple variables.