Non-invasive Characterization of Systemic Microvascular Reactivity by Near-infrared Diffuse Optical Spectroscopy in COVID-19 Patients

The ischemic challenge will consist in a standardized Vascular Occlusion Test (VOT), as previously described in the literature. Briefly, a blood pressure cuff will be placed proximal to the forearm, and rapidly inflated at 40 mmHg above systolic pressure, and kept inflated during three minutes. Then the cuff will be rapidly deflated. The resulting deoxygenation (DeO2) and reoxygenation (ReO2) slopes will be reported as change in O2 saturation over time.