Comparison of different methods to assess fistula flow

Area of Science:

• Nephrology
• Medical Devices
• Hemodialysis Technology

Background:

• Hemodialysis (HD) requires accurate monitoring of access flow (AF).
• Existing AF monitoring techniques include ultrasound (US), blood temperature monitoring (BTM), and online clearance monitoring (OCM).
• The influence of dialyzer blood flow (Q(B)), measurement timing, and patient position on AF monitoring requires investigation.

Purpose of the Study:

• To compare the accuracy and reliability of US, BTM, and OCM for monitoring AF in hemodialysis patients.
• To evaluate the impact of different dialyzer blood flow rates (Q(B)200-300 ml/min) on AF measurements.
• To assess how measurement time points (start/end of HD) and patient positioning affect AF monitoring.

Main Methods:

• Twenty hemodialysis patients were enrolled.
• Ultrasound (US), blood temperature monitoring (BTM), and online clearance monitoring (OCM) were initially used at Q(B)300 ml/min.
• OCM was excluded due to unreliability; US and BTM were further tested at Q(B)200 ml/min, different time points, and with position changes.

Main Results:

• AF measurements by US and BTM showed significant correlation (1,104 ± 607 ml/min vs. 1,264 ± 664 ml/min).
• No significant differences in AF were observed between Q(B)300 and Q(B)200 ml/min.
• AF decreased from the start to the end of HD sessions, but patient position did not impact AF measurements.

Conclusions:

• Blood temperature monitoring (BTM) and ultrasound (US) demonstrate good correlation for AF monitoring.
• These validated methods (BTM and US) can be reliably used at Q(B)200-300 ml/min.
• AF monitoring with BTM and US is effective regardless of patient position during hemodialysis.