Predictors of mortality in patients treated with continuous hemodiafiltration for acute renal failure in an intensive care setting

We performed this study to identify predictors of mortality in critically i ll patients treated with continuous venovenous hemodiafiltration (CVVHDF) f or acute renal failure in an intensive care setting. It was an uncontrolled , observational study that took place in a general intensive care unit in a university hospital. Forty-one patients undergoing CVVHDF for acute renal failure in a consecutive sample of 1,018 ICU treatments were studied. The u nderlying disease included 25 postsurgical cases and 16 medical cases. Betw een survivors (n = 23) and nonsurvivors (n = 18), the following factors wer e assessed: demographic data; the number and type of failed organs; Acute P hysiology and Chronic Health Evaluation (APACHE) II scores; urine productio n; pH; base excess; serum creatinine levels; bilirubin levels; lactate leve ls; platelet counts; and hemodynamic variables, including cardiac index and central venous pressure. On univariate analyses, the number of failed orga ns (p < 0.01), presence of hepatic failure (p < 0.01), APACHE II scores (p < 0.01), pH (p < 0.01), base excess (p < 0.001), average urinary production before the initiation of CVVHDF (p < 0.05), and serum bilirubin (p < 0.01) and lactate levels (p < 0.001) were significantly different. Multiple regr ession analysis identified serum bilirubin (p < 0.01) and lactate levels (p < 0.01) as the predictors of hospital mortality. Presence of hepatic failu re was also predictive of hospital mortality (p < 0.01) in the analysis of the type of organ failure. The cut-off value set at bilirubin levels > 10 m g/dl or arterial lactate levels > 3.5 mmol/L provided 83.3% sensitivity and 90.9% specificity in the prediction of hospital death. The crucial factors in predicting outcome of critically ill patients undergoing CVVHDF for ren al failure are elevated serum bilirubin and lactate levels at the onset of CVVHDF. Presence of hepatic failure, defined as both jaundice and coagulopa thy, may also worsen outcome of critically ill patients undergoing CVVHDF f or renal failure. The cut-off value set at bilirubin levels > 10 mg/dl or a rterial lactate levels > 3.5 mmol/L may serve as beneficial predictors of h ospital mortality.