High-volume continuous venovenous hemofiltration reduces mortality in critically ill patients with acute renal failure

Introduction

Renal replacement therapy is used in critically ill patients to treat acute renal failure. The most frequently used technique is continuous venovenous hemofiltration (CVVH). The appropriate dose of CVVH is currently a matter of debate. We compared hospital survival in patients receiving low-volume CVVH with patients receiving high-volume CVVH.

Methods

The ICU is an intensivist-led unit in a 500-bed teaching hospital. We performed a retrospective cohort study of all patients admitted to the ICU who were treated with renal replacement therapy between 1 January 2005 and 1 July 2007. Patients with acute renal failure only were treated with low-volume CVVH (35 ml/kg ultrafiltrate). Patients with acute renal failure and sepsis or multiorgan dysfunction syndrome were treated with high-volume CVVH (4 l/hour ultrafiltrate). All data were collected from the ICU database or from patient records.

Results

A total of 58 patients were included in the study (Table 1). Eighty-eight percent of patients received at least 80% of the prescribed dose. We found a trend towards a higher mortality in patients who received low-volume CVVH compared with patients who were treated with high-volume CVVH. In a logistic regression model with age, APACHE II score and CVVH dose as independent parameters, the age and CVVH dose were significant predictors of mortality (Table 2).

Table 1 Patient characteristics and crude hospital mortality

Table 2 Logistic regression model for hospital mortality (reference = low-dose CVVH)

Conclusion

High-volume CVVH decreases hospital mortality in critically ill patients with acute renal failure in this study. This is in agreement with the literature.