Abstract: FR-PO0498
Do Favorable Relative Blood Volume Levels Indicate a Characteristic Refill-to-Ultrafiltration Pattern?
Session Information
- Dialysis: Hemodiafiltration, Ultrafiltration, Profiling, and Interdialytic Symptoms
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Casper, Sabrina, Renal Research Institute, New York, New York, United States
- Meigel, Felix J., Renal Research Institute, New York, New York, United States
- Fuertinger, Doris H., Renal Research Institute, New York, New York, United States
- Ho, Kevin, Fresenius Medical Care Holdings Inc, Waltham, Massachusetts, United States
- Yueh, Sheng-Han, Renal Research Institute, New York, New York, United States
- Zhang, Hanjie, Renal Research Institute, New York, New York, United States
Background
Effective fluid management during hemodialysis (HD) is essential for maintaining hemodynamic stability and improving patient outcomes. As ultrafiltration volume (UFV) typically exceeds plasma refill volume (PRV), blood volume (BV) declines. While Preciado et al. identified relative blood volume (RBV) ranges associated with improved survival (Nephrol. Dial. Transplant., 2019), PRV-to-UFV ratios or profiles remain insufficiently characterized in literature.
Methods
We analyzed 289,846 HD sessions from 13,186 patients (Jan 2022-Apr 2023). Pre-dialysis BV was estimated using the Nadler formula, and continuous RBV changes were tracked via Crit-Line®. PRV was calculated as the difference between BV change and UFV removed. The PRV-to-UFV ratio was calculated in 30-minute intervals and classified as <0.5, 0.5-0.7, 0.7-0.9, or ≥0.9. A ratio ≥0.9 indicates that ≥90% of UFV is replaced by fluid shifting from the interstitial space. Sessions were stratified by whether the third-hour RBV fell within the favorable 86–92% range identified by Preciado et al. (Nephrol. Dial. Transplant., 2019).
Results
Post-HD weight averaged 82.8 ± 21.2 kg, and 60.4% of patients were male. Over the first 3 hours, mean UFV and PRV were 2.1 ± 0.8 L and 1.7 ± 0.7 L, respectively. At the third hour, 39.3% of treatments were within the favorable RBV range, 7.6% below, and 53.0% above.
As shown in Figure 1, PRV-to-UFV ratio trajectories in the in-target group (orange flows) showed substantial variability. Following an expected adjustment phase in the first 30 minutes, 48.3-56.9% of in-target treatments fell within the 0.7-0.9 range from 30 to 180 minutes. However, only 8% of in-target treatments remained consistently in this range, while 55.5-60.0% transitioned between different ratio categories over successive time intervals.
Conclusion
Attainment of a favorable RBV was not associated with a consistent PRV-to-UFV pattern. Instead, marked fluctuations were observed over prolonged half-hour intervals, with only 8% of treatments expressing temporal stability throughout the first three hours of treatment.
Funding
- Commercial Support – Fresenius Medical Care