Patients with COVID-19 show alterations in sublingual microcirculation and skin perfusion.
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Perfused vessels proportion and flow velocity decreases, and heterogeneity increases.
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The most striking result was the increase in vascular densities.
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High densities might result from angiogenesis or hypoxia-induced recruitment.
Abstract
Purpose
To assess the presence of sublingual microcirculatory and skin perfusion alterations in COVID-19 pneumonia.
Materials and methods
This is a preliminary report of a prospective observational study performed in four teaching intensive care units. We studied 27 mechanically ventilated patients with acute respiratory distress syndrome secondary to COVID-19. Sublingual microcirculation was assessed by hand-held videomicroscopy. A software-assisted analysis of videos was performed. We also measured capillary refill time.
Results
Patients were hemodynamically stable with normal lactate (1.8 [1.6–2.5] mmol/L) and high D-dimer (1.30 [0.58–2.93] μg/mL). Capillary refill time was prolonged (3.5 [3.0–5.0] s). Compared to previously reported normal values, total and perfused vascular density (21.9 ± 3.9 and 21.0 ± 3.5 mm/mm2) and heterogeneity flow index (0.91 ± 0.24) were high; and the proportion of perfused vessels (0.96 ± 0.03), microvascular flow index (2.79 ± 0.10), and red blood cell velocity (1124 ± 161 μm/s) were reduced. The proportion of perfused vessels was inversely correlated with total vascular density (Pearson r = −0.41, P = 0.03).
Conclusions
COVID-19 patients showed an altered tissue perfusion. Sublingual microcirculation was characterized by decreases in the proportion of perfused vessel and flow velocity along with high vascular densities. This last finding might be related to enhanced angiogenesis or hypoxia-induced capillary recruitment.
