Published online May 16, 2021. doi: 10.12998/wjcc.v9.i14.3385
Peer-review started: November 17, 2020
First decision: December 28, 2020
Revised: December 31, 2020
Accepted: January 25, 2021
Article in press: January 25, 2021
Published online: May 16, 2021
Several reports with clinical, histological and imaging data have observed the involvement of lung vascular function to explain the severe hypoxemia in coronavirus disease 2019 (COVID-19) patients. It has been hypothesized that an increased pulmonary blood flow associated with an impairment of hypoxic pulmonary vasoconstriction is responsible for an intrapulmonary shunt. COVID-19 may lead to refractory hypoxemia (PaO2/FiO2 ratio below 100 mmHg) despite mechanical ventilation and prone positioning. We hypothesized that the use of a pulmonary vasoconstrictor may help decrease the shunt and thus enhance oxygenation.
We report our experience with three patients with refractory hypoxemia treated with almitrine to enhance oxygenation. Low dose almitrine (Vectarion®; Servier, Suresnes, France) was started at an infusion rate of 4 μg × kg/min on a central line. The PaO2/FiO2 ratio and total respiratory system compliance during almitrine infusion were measured. For the three patients, the PaO2/FiO2 ratio time-course showed a dramatic increase whereas total respiratory system compliance was unchanged. The three patients were discharged from the intensive care unit. The intensive care unit length of stay for patient 1, patient 2 and patient 3 was 30 d, 32 d and 31 d, respectively. Weaning from mechanical ventilation was performed 13 d, 18 d and 15 d after almitrine infusion for patient 1, 2 and 3, respectively. We found no deleterious effects on the right ventricular function, which was similar to previous studies on almitrine safety.
Almitrine may be effective and safe to enhance oxygenation in coronavirus disease 2019 patients. Further controlled studies are required.
Core Tip: It has been hypothesized that increased pulmonary blood flow associated with impaired hypoxic vasoconstriction may lead to significant intrapulmonary shunt that plays a major role in coronavirus disease 2019 related severe hypoxia. In this report, three coronavirus disease 2019 patients with refractory hypoxemia were treated with continuous infusion of almitrine, a specific pulmonary vasoconstrictor. Almitrine infusion enhanced oxygenation of patients with severe coronavirus disease 2019 related acute respiratory distress syndrome without any change in pulmonary artery pressures and right ventricular function.