Convective renal replacement therapies for acute renal failure and end-stage renal disease

Although hemodialysis remains the primary treatment modality for the management of patients with end-stage renal disease (ESRD), its clearance of relatively large-sized uremic toxins is limited due to its primarily diffusive nature. Moreover, recent studies suggesting conventional, diffusion-based therapies may be limited in their ability to influence outcome in ESRD patients indicate the need for alternative chronic dialysis approaches, an example of which is convective therapies. In an analogous manner, a reassessment of the dialytic management of critically ill patients with acute renal failure (ARF) has also occurred recently based on clinical evidence that high-dose continuous hemofiltration improves survival. These recent clinical results suggest the utilization of convective therapies in both ARF and ESRD will increase in the future. This article provides a review of convective therapies, with an initial discussion of the determinants of convective solute removal. This is followed by a comprehensive overview of the manner in which hemofiltration and hemodiafiltration are applied clinically.