RESUMEN

Severe coronavirus disease 2019 is characterized by infected microvascular endothelial cells. The primary aim of this study was to investigate microvascular function in patients with critical coronavirus disease 2019. DESIGN: A prospective observational study was conducted in which patients with critical and severe COVID-19 were investigated during acute disease phase and at least 3 months after disease onset. SETTING: Single-center study at Danderyd University Hospital. PATIENTS: Twenty-three patients with critical coronavirus disease 2019 treated with noninvasive or invasive mechanical ventilation, seven patients with severe COVID-19 with dyspnea or need of oxygen supply up to 8 L/min, and 15 noncoronavirus disease controls. INTERVENTIONS: None. MEASUREMENTS: Skin perfusion was investigated through laser speckle contrast imaging before and after iontophoresis of acetylcholine and sodium nitroprusside for determination of the endothelial-dependent and the endothelial-independent vasodilation, respectively. MAIN RESULTS: Patients with critical COVID-19 had higher basal skin perfusion during both the acute (34 ± 9 perfusion unit; p = 0.0003) and the postinfectious phase (29 ± 8 perfusion unit; p = 0.04), compared with noncoronavirus disease controls (23 ± 7 perfusion unit). In addition, endothelial-dependent and endothelial-independent vasodilation were reduced in patients with critical COVID-19 during the acute disease phase (p < 0.001 for both), whereas no significant differences between patients and controls were found during the postinfectious phase. In patients with severe COVID-19, basal skin perfusion and endothelial-dependent vasodilatation were not significantly changed, whereas endothelial-independent vasodilatation was reduced (p = 0.02) compared with controls. CONCLUSIONS: Changes in skin microcirculation in patients with critical COVID-19 indicate that the infection induces a systemic microvascular impairment with persisting long-term effects on the microvascular function.