Rifle classification for predicting in-hospital mortality in critically ill sepsis patients

Severe sepsis and septic shock, often complicated by acute kidney injury (AKI), are the most common causes of mortality in noncoronary intensive care units (ICUs). This study investigates the outcomes of critically ill patients with sepsis and elucidates the association between prognosis and risk of renal failure, injury to the kidney, failure of kidney function, loss of kidney function, and end-stage renal failure (RIFLE) classification. A total of 121 sepsis patients were admitted to ICU from June 2003 to January 2004. Forty-seven demographic, clinical, and laboratory variables were prospectively recorded for post hoc analysis as predictors of survival on the first day of ICU admission. Overall in-hospital mortality rate was 47.9%. Mortality was significantly associated (chi-square for trend; P < 0.001) with RIFLE classification. Septic shock, RIFLE category, and number of organ system failures on the first day of ICU admission were independent predictors of hospital mortality according to forward conditional logistic regression. The severity of RIFLE classification correlated with organ system failure number and Acute Physiology and Chronic Health Evaluation (APACHE) II to IV and sequential organ failure assessment scores. Cumulative survival rates at 6-month follow-up after hospital discharge significantly (P < 0.05) differed between non-AKI versus RIFLE injury, non-AKI versus RIFLE failure (RIFLE-F), and RIFLE risk versus RIFLE F. At 6-month follow-up, full recovery of renal function was noted in 85% of surviving patients with AKI (RIFLE risk, RIFLE injury, and RIFLE-F). In conclusion, these findings are consistent with a role for RIFLE classification in accurately predicting in-hospital mortality and short-term prognosis in ICU sepsis patients.