Daily haemodialysis for acute renal failure

Current guidelines on dialysis adequacy for patients with acute renal failure are based upon extrapolation from end-stage renal disease. As a result, intermittent haemodialysis - the most commonly used modality of renal replacement therapy - is typically prescribed for 3 or 4 h three or more times per week. Recent data suggest that alternate day dialysis provides inadequate dialysis dosing in the majority of critically ill patients.

Measurements of urea kinetic modelling show that the delivered dose of dialysis is 20-30% lower than the prescribed dose and even less than adequate for a stable end-stage renal disease patient receiving haemodialysis three times per week. A recently published prospective comparison of two dialysis intensities (alternate day versus daily) demonstrated an association between increased treatment dose and improved outcome in critically ill patients. The beneficial effects of daily dialysis could be explained by lower uraemic toxicity, less fluid overload and a shorter duration of severe acute renal failure.

The limited data on the effects of dialysis dose on acute renal failure suggest that the relationship between acute renal failure comorbid conditions and death in critically ill patients is more complicated than generally recognized. There is no doubt that alternate day dialysis provides a suboptimal dose of dialysis with negative impact on the outcome. Significant differences render the use of most urea kinetic modelling equations problematic. Despite the current lack of further information we would recommend that haemodialysis should be dosed daily in many cases of hypercatabolic or anuric acute renal failure.