Ten Years Experience of In-Center Thrice Weekly Long Overnight Hemodialysis

Background and objectives: Published studies suggest that longer hemodialysis (HD) sessions are associated with improved morbidity and mortality, but few centers offer long sessions. The Western Infirmary renal unit has offered long overnight hemodialysis (LOH) (6 to 7 h) thrice weekly since 1998. The aim of this study was to describe patients who chose LOH and compare outcomes with patients on conventional hours (4 to 5 h) HD.Design, settings, participants, & measurements: Patients who ever had LOH for three or more consecutive sessions were identified (n = 146). Indices of urea reduction ratio (URR), anemia, hyperphosphatemia, and predialysis BP (BP) control in a subgroup of all patients on LOH for at least 1 yr since 2004 were compared with age, sex, and diabetes-matched controls undergoing conventional duration HD.Results: The mean age at the time of starting LOH was 51.8 yr and 74.7% started with a functioning arteriovenous fistula. Median duration of continuous LOH was 1.6 yr. Of those no longer on LOH, only 33.3% reverted to conventional hours HD (mean duration LOH 2.2 yr). When comparing LOH and conventional HD cohorts, there was increased URR and mean hemoglobin with a trend toward lower mean erythropoietin index. There was a trend toward fewer phosphate binder tablets but no difference in mean serum phosphate, BP, or number of prescribed antihypertensive medicines.Conclusions: LOH is a well tolerated hemodialysis option, associated with improved URR and better control of anemia.There is no consensus on the optimal duration or frequency of hemodialysis sessions for patients with established renal failure, but constraints on time and resources mean that 3 to 5 hr, three times a week hemodialysis is routine practice for most hemodialysis units.Most of the evidence relating to dialysis session duration comes from small observational, single-center studies, but one randomized control trial has been performed in the United States (1). Several of these centers have reported data suggesting more frequent or longer hemodialysis sessions may be associated with improvements in all or some of the following: small solute clearance, BP control, left ventricular hypertrophy, anemia, hyperphosphatemia, nutritional parameters, and mortality (2–9).The Western Infirmary renal unit has offered long overnight hemodialysis (LOH) since 1998. This consists of 6 to 7 h sessions three times per week at the main unit and one of our satellite units. The unit decided to provide thrice weekly in-center LOH in the belief that improved solute clearance and more prolonged ultrafiltration might be associated with improved outcomes and that the option of overnight hemodialysis might be socially attractive to some patients, as well as to increase dialysis capacity. We place few restrictions on the type of patients who can receive LOH. Patients are offered LOH if they do not need a two-person ambulance to take them to and from their dialysis sessions and are prepared to travel home from dialysis sessions at 2 to 4 a.m.The aim of this study was to describe all of the patients who chose LOH over the 10-yr period. In a subset of these patients, a case-controlled analysis was also performed of the impact of LOH on small solute clearance, hyperphosphatemia, anemia, and BP compared with age, sex, and diabetes-matched controls undergoing conventional duration hemodialysis (HD). The study hoped to demonstrate that LOH was a suitable modality for the majority of dialysis patients and would be associated with clinically meaningful benefits.