Prognosis of acute renal failure: an evaluation of proposed consensus criteria

Objectives: To validate the recently proposed criteria for acute renal injury (ARI), acute renal failure syndrome (ARFS) and severe acute renal failure syndrome (SARFS) and to evaluate the significance of other prognostic factors. Design and settings: Retrospective analysis of the Riyadh ICU Program database of patients admitted to 22 ICUs in UK and Germany between 1989 and 1998. Patients: Included in the study were 41,972 patients, of whom 7,522 (17.9%) had ARI, 2,641 (6.3%) had ARFS and 1,747 (4.2%) had SARFS. Results: Patients with ARI, ARFS or SARFS had a hospital mortality of 29.5%, 49.2% or 63.0%, respectively, compared to 10.3% among patients without acute renal failure. In the presence of contemporaneous failure of any other organs on the day of acute renal failure, hospital mortality increased to 73.3%, 76.2%, 72.1% and 18%, respectively. Multivariate analysis showed that non-surgical admission, need for emergency surgery, development of acute renal failure during stay in ICU, need for mechanical ventilation and the number of other failed organ systems had a greater impact on prognosis than the need for renal replacement therapy. Conclusions: The proposed criteria for ARI, ARFS and SARFS correlated with mortality, but other factors had a greater impact on prognosis. Renal replacement therapy did not increase the risk of hospital mortality among patients with acute renal failure.