Kidney Week

Abstract: TH-PO0712

Feasibility of Integrated Hematocrit and Oxygen Monitoring with CKRT

Session Information

• AKI: Prevention, Diagnostics, and Management
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Sreedhar, Siva, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Siva Sreedhar, MD

• Kennelly, Molly B., University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Molly B. Kennelly

• Hull, Charlie, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Charlie Hull

• Negoianu, Dan, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Dan Negoianu, MD

• Dember, Laura M., University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Laura M. Dember, MD, FASN

• Brotman, Christina HW, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Christina HW Brotman, MD, MS, FASN

Background

Volume management during continuous kidney replacement therapy (CKRT) is complex due to the challenges of treating fluid overload while mitigating the detrimental effects of rapid fluid removal (ultrafiltration). Non-invasive monitoring techniques that provide real-time assessment of hemodynamic tolerance to ultrafiltration have been studied in hemodialysis. We adapted an optical monitoring technique to assess the feasibility of continuous hematocrit and oxygen monitoring during CKRT.

Methods

This is a prospective observational study of adult patients receiving CKRT>24 hours in medical intensive care units. During scheduled CKRT filter change, a sterile blood chamber was connected to the arterial port of the central venous catheter. CritLine-IV monitors were used to collect per-minute hematocrit (HCT) and oxygen saturation (corresponding to central venous oxygen saturations, ScvO2) for the filter lifespan. HCT and ScvO2 values from the CritLine were compared to values from routine laboratory studies. Mixed effects modeling accounting for within-patient clustering was used to assess mean bias. Bland-Altman analysis was conducted for visual analysis of agreement.

Results

We present data from interim analysis after enrollment of 10 participants, 7 of which completed study measurements. Median filter lifespan with the adaptors was 45.2 hours without clotting. We analyzed 89 CritLine HCT readings. Mean bias between CritLine HCT versus laboratory HCT were as follows: venous blood gas 1.38 (0.14, 2.62), arterial blood gas 1.71 (0.79, 2.64), and CBC 2.89 (1.68, 4.10). We also analyzed 33 CritLine ScvO2 readings from 5 patients which had a mean bias of 8.41 (7.26, 9.55), though there was high intra-patient variability. Bland-Altman analysis showed mild proportional bias for HCT comparisons. No overt temporal bias was seen.

Conclusion

Integration of inline monitoring with CKRT was feasible and preliminary data did not show increased access pressures or filter clotting. HCT values from CritLine demonstrate good agreement with plasma and whole blood measurements during CKRT. Further studies are underway to understand how these metrics can guide vasopressor adjustment and ultrafiltration during CKRT.

Comparison of Critline- versus laboratory-derived HCT and ScvO2

Funding

• Commercial Support – Investigator initiated research grant (Fresenius)