Individually adjusted absolute blood volume feedback control: A promising solution for intradialytic hypotension

Area of Science:

• Nephrology
• Cardiovascular Physiology
• Biomedical Engineering

Background:

• Intradialytic hypotension (IDH) is a frequent complication of hemodialysis (HD), often caused by uncompensated reductions in absolute blood volume (ABV).
• Blood volume monitoring (BVM) systems can measure ABV, enabling potential biofeedback control of ultrafiltration (UF) to manage blood volume.
• Identifying individual critical ABV thresholds is key to preventing IDH.

Purpose of the Study:

• To determine individual critical absolute blood volume (ABV) thresholds in patients undergoing hemodialysis (HD).
• To evaluate the efficacy of an ABV feedback control system in preventing intradialytic hypotension (IDH).

Main Methods:

• Twenty-four patients underwent three HD treatments with continuous measurement of ABV and blood pressure (BP).
• Individual critical ABV thresholds were identified at the time of hypotension or symptoms.
• An ABV feedback control system was implemented in subsequent treatments to maintain ABV above the critical threshold.

Main Results:

• ABV consistently decreased during HD treatments.
• Thirteen IDH events occurred in eight patients, with a mean ABV of 71.07 mL/kg at hypotension.
• ABV feedback control successfully prevented IDH in 21 out of 22 treatments by maintaining ABV above critical levels, reducing both ABV and systolic BP drops.

Conclusions:

• An individualized ABV feedback control system effectively prevents intradialytic hypotension (IDH) in hemodialysis (HD) patients.
• Maintaining absolute blood volume (ABV) above a critical threshold is crucial for IDH prevention.
• This approach reduces hemodynamic instability without compromising prescribed ultrafiltration volumes.