Dialysis time: does it matter? A reappraisal of existing literature

The length of time (Td) required for adequate maintenance hemodialysis therapy is perceived as a substantial patient burden. Technological advancements have allowed shortening Td over the past three decades. However, failure to detect improved outcomes with higher dialysis dose has prompted renewed interest in the potential impact of longer Td.

Ongoing trials are focused on increasing the frequency of treatments, although the feasibility of having most patients agreeing to more than five treatments per week remain doubtful. Furthermore, survival was better in short daily hemodialysis with Td of 180 vs. 90 min. Within thrice weekly dialysis, several recent epidemiological studies have shown improved survival associated with Td more than 4 h. Improved outcomes for long in-center nocturnal hemodialysis (6-8 h, 3×/week), similar to what has been performed in Tassin for the last 30 years, have also been reported.

Compelling rationale and recent outcome data support use of longer Td. Improved management of salt and water may be the cause for the dissociation of dialysis time and small molecule clearance. In most industrialized countries, hemodialysis care systems in place have the capacity to accommodate it. Until such time that results from prospective randomized trials are available, we believe that physicians should prescribe and exert all efforts to convince thrice weekly hemodialysis patients to accept 4 h as minimum Td.