Kidney Week

Abstract: SA-PO1071

Reducing the Ecological Footprint of Hemodialysis Through Dialysate Flow Rate Optimization: A Quality Improvement Initiative

Session Information

• Kidney Replacement Therapy and Care Delivery Innovations
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Shah, Meera, University of Toronto, Toronto, Ontario, Canada

Meera Shah, MD

• Chennou, Fella, University of Toronto, Toronto, Ontario, Canada

Fella Chennou, MD

• Shah, Samveg, University of Toronto, Toronto, Ontario, Canada

Samveg Shah, MD

• Alkhayyat, Abdulaziz, University of Toronto, Toronto, Ontario, Canada

Abdulaziz Alkhayyat, MD

• Cooper, Matthew, University of Toronto, Toronto, Ontario, Canada

Matthew Cooper, MD, MSc

• Wald, Ron, University of Toronto, Toronto, Ontario, Canada

Ron Wald, MDCM, MPH

• Harel, Ziv, University of Toronto, Toronto, Ontario, Canada

Ziv Harel, MD, MS

• Dubrofsky, Lisa, University of Toronto, Toronto, Ontario, Canada

Lisa Dubrofsky, MD

• Rodriguez Ramirez, Sonia, University of Toronto, Toronto, Ontario, Canada

Sonia Rodriguez Ramirez, MD, MSc

Background

Hemodialysis (HD) has an important ecological impact, particularly due to significant water consumption. Water consumption is particularly sensitive to the dialysate flow rate (Qd). Recent studies show that small molecule clearance remains largely intact with Qd as low as 500 ml/min, yet in our institution, about 60% of patients are prescribed a Qd exceeding 500 mL/min.

Methods

We undertook a quality improvement initiative at St-Michael’s Hospital, aiming to reduce water consumption by capping Qd rate at 500 mL/min or 1.5 times the blood flow rate (whichever is lower). We selected patients on conventional, in-center maintenance HD with adequate average clearance metrics over two consecutive months before project implementation, defined as a URR >70% and serum [K+] < 6.0 mmol/L. The primary outcome was the proportion of patients with Qd of 500 mL/min or less. Secondary outcomes included URR and [K+] at 6 weeks, as well as estimated water and greenhouse gas (GHG) savings.

Results

Out of 194 HD recipients (mean age 65 years, 62% males), 99 (51%) were eligible. Prescription changes were implemented in January 2026, and 93 patients completed the 6-week follow-up period. The average Qd of the HD unit showed a sustained decrease 6 weeks post intervention, and 85% of included patients receiving a Qd of 500 ml/min or less. Dialysis adequacy was preserved, with mean URR of 76.1% at 6-weeks vs 76.3% at baseline (p=0.83). There was no significant change in [K+] before and after implementation (4.83 vs. 4.85 mmol/L respectively, p=0.80). The intervention was associated with meaningful reductions in per-treatment resource consumption, including water (22 L), energy (0.48 kWh), and acid concentrate (0.48 L). Preliminary lifecycle analysis estimates that unit-wide implementation of reduced Qd would yield an annual reduction of GHG emissions of 3,200 kg CO2 equivalents. Decreased acid consumption is projected to generate CAD $20,000 in annual savings.

Conclusion

Reducing dialysate flow rates is clinically safe, environmentally impactful and cost-saving.

Acknowledgment

Honary mentions to Ms. Weijia Shi, Mr. Keiji Hayashi, Mr.Kevin Barlow, and Mr.Simranjeet Singh for the support on the project.

Figure 1: Average Qd (ml/min) for hemodialysis treatments at St. Michael’s Hospital.