Kidney Week

Abstract: SA-PO1079

Continuous Oxygen Monitoring Reveals Link Between Arterial Oxygen Saturation Oscillations and Mortality Risk in Patients on Hemodialysis

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

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

Andrea Nandorine Ban, MS, MSc

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

Peter Kotanko, MD, FASN

• Kooman, Jeroen, Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Jeroen Kooman, MD, PhD

• Usvyat, Len A., Renal Research Institute, New York, New York, United States

Len A. Usvyat, PhD, FASN

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

Hanjie Zhang, PhD

Background

Intermittent oscillations in arterial oxygen saturation (SaO₂), described as saw-tooth patterns (STP), have been observed during hemodialysis (HD) (Zhang et al., BMC Nephrology 2025). Their clinical significance remains unclear. We evaluated the association between intradialytic SaO₂ oscillation rate and mortality.

Methods

We analyzed a large US HD cohort from Jan 2021 to July 2023. SaO₂ was continuously monitored during HD using the FDA-approved Crit-Line device, with measurements recorded every 10 seconds. For each patient, the percent of treatment time exhibiting oscillatory SaO₂ patterns was calculated. Patients were stratified into two groups: <10% vs ≥10% oscillation time. Survival was assessed using Kaplan–Meier analysis and compared by log-rank test. A multivariable Cox proportional hazards model was fitted with adjustment for demographics (age, gender, race), comorbidities (COPD, CHF, diabetes), dialysis vintage, and clinical/laboratory parameters including albumin, hemoglobin, neutrophil-to-lymphocyte ratio, interdialytic weight gain, post-HD systolic BP, ultrafiltration rate, BMI, ESA dose, and average SaO₂ at treatment start (5-20 minutes).

Results

After data cleaning, 31,337 patients were included. We recorded 4,625 deaths. Kaplan–Meier curves separated early with higher mortality in patients with ≥10% oscillation time (log-rank p<0.001) (Figure 1). In adjusted Cox analysis, greater SaO₂ oscillation burden was independently associated with mortality (HR 1.03 per 10% increase; 95% CI 1.01–1.05; p=0.002).

Conclusion

Intradialytic SaO₂ oscillations are independently associated with increased mortality in HD patients. Continuous SaO₂ monitoring may identify high-risk individuals and represent a potential target for intervention.

Acknowledgment

Artificial intelligence tools were used to assist in the writing of this abstract. The authors reviewed and edited the content and take full responsibility for the final version.

Figure 1. Kaplan–Meier survival curves by saw-tooth pattern (STP) burden of intradialytic SaO₂ (<10% vs ≥10%). Numbers at risk are shown.

Funding

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