Twice-Weekly Hemodialysis May be Sufficient in Patients with Residual Kidney Function

Seolhyun Lee, MD

Credit: Stanford Medicine

Data from a study presented at the American Society of Nephrology Kidney Week 2023 provide insight into the safety and efficacy of twice- versus thrice-weekly hemodialysis.

Presented by Seolhyun Lee, MD, clinical assistant professor in the nephrology division of the Stanford University department of medicine, results highlight the potential for symptom improvement without a significant increase in treatment time among patients treated twice weekly compared to those treated thrice weekly.¹

“The most recent 2015 update of the Kidney Disease Outcomes Quality Initiative dialysis adequacy guidelines increased the contribution assigned to residual kidney function in calculating standard Kt/Vurea,” wrote investigators.¹ “However, no study has yet assessed the effect of prescribing twice weekly hemodialysis according to this guideline on patients' symptoms or uremic solute levels.”

The US Centers for Disease Control and Prevention estimates 35.5 million adults in the US have chronic kidney disease. Hemodialysis is used to treat advanced kidney failure, although the necessary frequency of treatment is debated.²

To compare the effects of twice-weekly versus thrice-weekly hemodialysis, investigators assigned 24 hemodialysis patients with residual kidney urea clearance 4.7±1.8 ml/min to receive 4 weeks of hemodialysis achieving standard Kt/V 2.2 incorporating residual kidney urea clearance using the 2015 KDOQI guidelines or a per treatment spKt/V 1.3 regardless of residual kidney urea clearance.¹

For inclusion in the study, patients were required to have residual kidney urea clearance >2.5 ml/min and have been on hemodialysis for at least 2 months. Investigators compared symptom scores and pre-treatment plasma levels of urea, secreted solutes p-cresol sulfate and hippurate, and beta-2 microglobulin at the end of each 4-week period.¹

Upon analysis, symptoms were significantly better with twice-weekly hemodialysis compared to thrice-weekly hemodialysis, as assessed by the following:

• KDQOL36 Symptom component (86±14 vs 82±18; P = .001)
• Dialysis Symptom Index (26±26 vs 33±31; P = .008)
• Post-dialysis recovery time (1.6±0.8 vs 1.9±1.0; P = .01)

Investigators also pointed out twice weekly hemodialysis provided a standard Kt/V of 2.7±0.5 without a significant increase in treatment time compared to thrice-weekly (195±21 min vs 3X: 191±17 min, respectively; P = .07). Residual kidney urea clearance, ultrafiltration rate, and pre-treatment plasma potassium were similar between the treatments, and no patients were withdrawn for fluid overload or hyperkalemia.1

Plasma analysis showed an increased pre-treatment level of urea with twice-weekly hemodialysis (76±22 vs 54±13 mg/dl; P < .001). The levels of secreted solutes p-cresol sulfate (4.0±1.6 vs. 3.7±1.3 mg/dl; P = .39), hippurate (2.7±3.0 vs 2.2±1.9 mg/dl; P = .84), and beta-2 microglobulin (22±7 vs 21±6 mg/L; P = .80) were not significantly greater with twice-weekly hemodialysis compared to thrice-weekly hemodialysis.1

“2X hemodialysis can be safely prescribed with the increased contribution assigned to residual kidney urea clearance by the 2015 KDOQI guidelines. With 2X hemodialysis, symptoms were improved and the continuous function of the residual kidneys controlled fluid gain, potassium, and plasma levels of uremic solutes without a need to increase treatment time,” concluded investigators.¹

References:

1. Lee S, Bolanos CG, Bonde SS, et al. Twice Weekly vs. Thrice Weekly Hemodialysis in Patients with Residual Kidney Function. Paper Presented at: American Society of Nephrology Kidney Week 2023. November 1-5, 2023.
2. Centers for Disease Control and Prevention. Chronic Kidney Disease in the United States, 2023. Accessed November 2, 2023. https://www.cdc.gov/kidneydisease/basics.html