Determining blood and plasma volumes using bioelectrical response spectroscopy

Area of Science:

• Biomedical Engineering
• Medical Physics
• Cardiovascular Physiology

Background:

• Assessing total blood volume (TBV) and plasma volume (PV) is crucial for clinical management.
• Current methods like dilution techniques can be invasive or time-consuming.
• The hypothesis posits that electrical fields generated by blood flow can non-invasively estimate blood volumes.

Purpose of the Study:

• To investigate the potential of Bioelectrical Response Spectroscopy (BERS) for estimating TBV and PV.
• To determine the validity and accuracy of BERS models compared to established dilution methods.

Main Methods:

• Electrical circuit parameters (inductance, capacitance, resistance) were derived using Bioelectrical Response Spectroscopy (BERS).
• BERS-derived parameters from 19 subjects were used to model TBV and PV.
• Models were validated against 125I-albumin dilution measurements in a cross-validation group of 10 subjects.

Main Results:

• BERS models demonstrated high accuracy in assessing TBV and PV, with non-significant mean differences compared to dilution methods.
• Strong correlations (r > 0.92) and low standard error of the estimate (SEE < 7.7%) were observed.
• Bland-Altman analysis indicated clinical equivalency between BERS and dilution methods.

Conclusions:

• BERS models show significant promise for accurately assessing TBV and PV.
• The non-invasive nature of BERS offers a potential advantage over traditional methods.
• Further research and validation are necessary before widespread clinical or research implementation.