Relative Tissue Oxygenation and Temperature Changes for Detecting Early Upper Extremity Skin Ischemia

Area of Science:

• Vascular Medicine
• Biomedical Engineering
• Diagnostic Technologies

Background:

• Assessing upper extremity ischemia noninvasively is crucial for timely intervention.
• Skin pigmentation can pose challenges for certain diagnostic methods.
• Reliable, universally applicable ischemia detection is needed.

Purpose of the Study:

• To evaluate near-infrared spectroscopy (NIRS) and skin surface temperature for noninvasive assessment of upper extremity ischemia.
• To determine if these methods are reliable across different skin pigmentation levels.

Main Methods:

• Healthy participants with varying skin types (Fitzpatrick scale, von Luschan scale, self-described race) were studied.
• Temporary ischemia was induced using tourniquets on the upper limb.
• Near-infrared spectroscopy and surface temperature probes monitored tissue oxygenation and temperature.

Main Results:

• Near-infrared spectroscopy demonstrated a consistent decrease in tissue oxygenation in all participants during ischemia.
• Skin surface temperature readings showed no significant changes.
• NIRS effectiveness was not significantly affected by Fitzpatrick skin types or von Luschan scores.

Conclusions:

• Near-infrared spectroscopy is a reliable, noninvasive method for detecting upper extremity ischemia.
• NIRS performs consistently across a spectrum of skin pigmentation.
• Skin surface temperature is not a reliable indicator of ischemia in this context.