Temporal and spatiotemporal variability in comprehensive forearm skin microcirculation assessment during occlusion...

Area of Science:

• Biomedical Engineering
• Physiology
• Medical Diagnostics

Background:

• Forearm skin hyperemia post-brachial occlusion is used to assess peripheral arterial disease and endothelial dysfunction.
• Novel fiberoptic systems offer comprehensive microcirculation characterization.

Purpose of the Study:

• To evaluate and compare temporal and spatiotemporal variabilities of forearm skin microcirculation parameters.
• To assess the repeatability and agreement of these parameters using Laser Doppler Flowmetry and Diffuse Reflectance Spectroscopy.

Main Methods:

• Ten healthy subjects underwent repeated arterial and venous forearm occlusions (AO, VO).
• Measurements included speed-resolved perfusion (PerfSR,<1, PerfSR,tot), red blood cell concentration (CRBC), and oxygenation (SO2).
• Repeatability was assessed using coefficient of variation (CV) and intra-class correlation coefficient (ICC).

Main Results:

• Temporal CVs for perfusion, CRBC, and SO2 were low (9-14%), with excellent ICC (>0.75).
• Spatiotemporal CVs for perfusion were higher (18-33%) compared to temporal CVs.
• Specific parameters (CRBC, SO2, PerfSR,<1) showed acceptable repeatability and fair-good agreement under certain occlusion conditions.

Conclusions:

• Skin microcirculation parameters exhibit excellent temporal repeatability but poorer spatiotemporal repeatability, particularly for perfusion.
• Certain parameters demonstrated acceptable reliability for assessing microcirculation during and after forearm occlusions.
• Further research is needed to determine the clinical utility of these parameters in discriminating endothelial function.