Access flow measurement by indicator dilution without indicator injection: effect of switch location
D Schneditz1, F M van der Sande, I Bachler
1Institute of Physiology, Medical University of Graz, Graz, Austria. daniel.schneditz@meduni-graz.at
The International Journal of Artificial Organs
|December 11, 2007
Summary
The study reveals that switching bloodlines during dialysis acts as a dilution experiment, simplifying access flow measurement. Temperature changes indicate the switch location, requiring specific algorithms for accurate flow calculations.
Area of Science:
- Nephrology
- Biomedical Engineering
- Medical Devices
Background:
- Traditional access flow measurement involves reversing blood flow for dilution.
- Recent findings show that line switching itself can initiate a dilution process.
- This eliminates the need for a separate indicator injection.
Purpose of the Study:
- To investigate the effects of switching bloodlines at different extracorporeal circulation locations.
- To evaluate extracorporeal temperatures as a marker for these effects.
- To determine the impact of switch location on access flow measurement accuracy.
Main Methods:
- Studied the effects of switching bloodlines at two distinct locations.
- Utilized extracorporeal temperatures as the primary marker for dilution.
- Analyzed temperature changes in relation to switch position and sensors.
Main Results:
- Temperature changes were observed to be dependent on the switch location relative to temperature sensors.
- Different switching positions necessitate distinct algorithms for accurate access flow calculation.
- The line switch itself serves as a dilution experiment, simplifying measurement.
Conclusions:
- Bloodline switching in extracorporeal circulation can be leveraged for access flow measurement.
- Extracorporeal temperature monitoring effectively tracks dilution effects.
- Accurate access flow calculation requires location-specific algorithms based on temperature changes.
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