A prospective comparative study of continuous arteriovenous hemodiafiltration and continuous venovenous hemodiafiltration in critically ill patients.

We have prospectively studied and compared two consecutive groups of critically ill patients treated with either continuous arteriovenous hemodiafiltration (CAVHD) (n = 28) or continuous venovenous hemodiafiltration (CVVHD) (n = 25) to establish the technique of choice. The two groups were comparable in mean age (59 v 58 years), mean Acute Physiology and Chronic Health Evaluation (APACHE) II score (29.6 v 27.4, P = NS), requirements for inotropic drugs, and mean number of failing organs (2.9 v 3.2). CVVHD led to a greater amount of hourly ultrafiltrate (mean, 590 v 424 mL; P < 0.001), but urea and creatinine clearances were not significantly different with the two techniques. Twelve patients survived in the CAVHD group (42.8%) and 13 in the CVVHD group (52%; P = NS). The major advantage for CVVHD use was the substantial decrease in the number of access-related complications (2 v 10; P < 0.025). We conclude that while CVVHD does not offer a significant increase in solute clearance, it significantly minimizes vascular access-related morbidity and should therefore be regarded as the therapeutic modality of choice.