Arteriovenous hemodiafiltration associated with continuous arteriovenous hemofiltration: a combined therapy for acute renal failure in the hypercatabolic patient.

Abstract

To increase the efficiency of continuous arteriovenous hemofiltration (CAVH) in cases of severe catabolism, we used a modified CAVH treatment, called arteriovenous hemodiafiltration (AVHDF), in 4 patients. The transport of solutes was increased by providing the infusion of a counter current flow of urea-free solutions in the UF compartment of a standard CAVH circuit. Patients were treated with standard CAVH and, when a more efficient treatment was required, intermittent daily sessions of AVHDF were performed using the same filter and lines. The urea kinetic study enabled the calculation of the time needed to perform AVHDF, in addition to standard CAVH, to maintain the blood urea nitrogen (BUN) level under control. A dialysate flow rate of 300 ml/min made it possible to increase the urea nitrogen mass transfer rate from 10 to 65 mg/min and the clearance from 10.5 to 37.5 ml/min. The addition of AVHDF to CAVH enabled the control of BUN levels in the 4 patients affected by acute renal failure and a severe catabolic state. The technique is simple, does not require additional devices, and maintains the advantages of CAVH providing a better efficiency in terms of solute removal.