RIFLE classification and mortality in obstetric patients admitted to the intensive care unit with acute kidney injury: a 3-year prospective study.

OBJECTIVE

This study is to assess the correlation of risk, injury, failure, loss, and end-stage renal failure (RIFLE) classification with hospital mortality in intensive care unit (ICU) obstetric patients and to evaluate the relation of acute kidney injury (AKI) to other risk factors.

METHODS

The 4 stages of RIFLE (nonacute renal failure, risk, injury, and failure) were scored from 0 to 3 points, respectively. The prognostic performance of the RIFLE score was compared to the general ICU models.

RESULTS

AKI occurred in 30 (5.88%) of patients admitted to ICU. The main causes of AKI were hemolysis, elevated liver enzymes, and low platelet syndrome 13 (43%), pregnancy-related hypertension 9 (30%), puerperal sepsis 3 (10%), abruption placentae 2 (6.6%), disseminated intravascular coagulopathy 2 (6.6%), and anesthetic complications 1 (3.3%). According to the RIFLE criteria, patients were classified into Risk (3.3%), Injury (16.6%), Failure (33.3%), and Loss (46.6%). Maternal mortality from total ICU admission occurred in 51 (10%) cases, of these 16 (31.3%) cases were due to AKI. Independent risk factors associated with mortality were hyperbilirubinemia, low levels of HCO3, and RIFLE. Receiver-operator characteristic curves for ICU patients according to RIFLE score showed area under the curve = 0.824.

CONCLUSION

The RIFLE classification system could predict the risk of mortality from AKI in obstetric ICU patients and mortality was positively associated with high RIFLE classes.