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Related Experiment Video

Updated: Dec 4, 2025

Non-Invasive Monitoring of Microvascular Oxygenation and Reactive Hyperemia using Hybrid, Near-Infrared Diffuse Optical Spectroscopy for Critical Care

Non-Invasive Monitoring of Microvascular Oxygenation and Reactive Hyperemia using Hybrid, Near-Infrared Diffuse Optical Spectroscopy for Critical Care

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Microcirculation alterations in severe COVID-19 pneumonia.

Vanina Siham Kanoore Edul¹, Juan Francisco Caminos Eguillor², Gonzalo Ferrara³

¹Hospital Juan A Fernández, Ciudad Autónoma de Buenos Aires, Argentina; Cátedra de Farmacología Aplicada, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina; Sanatorio Otamendi, Buenos Aires, Argentina.

Journal of Critical Care

|October 23, 2020

Summary

COVID-19 pneumonia alters tissue perfusion, with reduced sublingual microvascular flow and velocity. Patients exhibited high vascular densities, potentially due to angiogenesis or hypoxia, indicating significant microcirculatory changes.

Keywords:

COVID-19 Capillary refill time Microcirculation Pneumonia

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Intravital Widefield Fluorescence Microscopy of Pulmonary Microcirculation in Experimental Acute Lung Injury Using a Vacuum-Stabilized Imaging System

Published on: April 6, 2022

Area of Science:

Critical Care Medicine
Microcirculation Research
COVID-19 Pathophysiology

Background:

COVID-19 pneumonia can lead to systemic complications, including microcirculatory dysfunction.
Assessing tissue perfusion is crucial for managing critically ill patients with COVID-19.

Purpose of the Study:

To investigate sublingual microcirculatory and skin perfusion alterations in mechanically ventilated COVID-19 pneumonia patients.
To characterize microvascular changes associated with COVID-19 acute respiratory distress syndrome.

Main Methods:

Prospective observational study of 27 mechanically ventilated COVID-19 patients.
Sublingual microcirculation assessed using hand-held videomicroscopy with software analysis.
Capillary refill time measured to evaluate peripheral perfusion.

Main Results:

Patients presented with prolonged capillary refill time (3.5s).
Sublingual microcirculation showed reduced proportion of perfused vessels (0.96) and lower red blood cell velocity (1124 μm/s).
High total and perfused vascular densities (21.9 mm/mm² and 21.0 mm/mm²) were observed, with an inverse correlation between perfused vessels and total vascular density.

Conclusions:

COVID-19 pneumonia is associated with significant alterations in tissue perfusion and sublingual microcirculation.
Observed microcirculatory changes include decreased vessel perfusion and flow velocity, alongside increased vascular density.
Elevated vascular density may indicate compensatory angiogenesis or hypoxia-driven capillary recruitment in response to COVID-19.