Kidney Week

Abstract: SA-PO417

Change of Central Venous Oxygen Saturation during Hemodialysis: A Real-Time Window into Intradialytic Hemodynamics

Session Information

• Hemodialysis and Frequent Dialysis - 2
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Nandorine Ban, Andrea, Renal Research Institute, New York, New York, United States

Andrea Nandorine Ban, MSc

• Filardi, Vincent, Renal Research Institute, New York, New York, United States

Vincent Filardi

• Wang, Lin-Chun, Renal Research Institute, New York, New York, United States

Lin-Chun Wang, MS

• Ye, Xiaoling, Renal Research Institute, New York, New York, United States

Xiaoling Ye, PhD, MPH

• Kotanko, Peter, Renal Research Institute, New York, New York, United States

Peter Kotanko, MD, FASN

• Zhang, Hanjie, Renal Research Institute, New York, New York, United States

Hanjie Zhang, PhD

Background

Low central venous oxygen saturation (ScvO₂) is associated with morbidity and mortality in hemodialysis (HD) patients. However, the exact dynamic of ScvO₂ during HD remains unknown.

Methods

In patients with central venous catheter (CVC) as vascular access, we used the Crit-Line monitor (CLM; Fresenius Medical Care, Waltham, MA) to record ScvO₂ every 10 seconds. Data were uploaded to the cloud in real-time. We extracted CLM data between 1/14/2021, and 7/30/2023.

Per Fick’s principle, ScvO₂ is determined by the upper body blood flow (UBBF), arterial oxygen saturation (SaO₂) and oxygen content (1.34×Hgb), and the upper body oxygen utilization (utilO₂) as follows: ScvO₂ = SaO₂ - (100×utilO₂) / (1.34×Hgb×UBBF). For the derivation of this equation see Rosales et al. (Blood Purif, 2018).

ScvO₂ at HD start is calculated as the mean ScvO₂ between minutes 5 and 20. ScvO₂ at the HD end is calculated as the mean ScvO₂ in the last 5-20 minutes. We dropped the treatments with less than 5 minutes measurements either at the beginning or at the end of the session.

Results

After data cleaning, our analytic cohort comprised over 1 million HD sessions in more than 31,000 patients with CVC. Average ScvO₂ at the beginning of the HD session was 64.7±8.3% and at the end 62.1±9.5%, indicating a mean intradialytic ScvO₂ decline of 2.65% (95% CI: 2.63 to 2.66) (Fig. 1).

Conclusion

Our results show a drop of ScvO₂ during HD. We hypothesize that an intradialytic decline of cardiac output, and consequently also of UBBF, is the predominant factor leading to the drop in ScvO₂. The goal of future research is to correlate ScvO₂ changes with clinical outcomes. Monitoring ScvO₂ during HD could provide real-time insights into intradialytic hemodynamics and may eventually result in improved HD procedures.

Funding

• Commercial Support – Renal Research Institute, New York, NY, a wholly owned subsidiary of Fresenius Medical Care.