Effects of rescue inhaled nitric oxide on right ventricle and pulmonary circulation in severe COVID-related acute respiratory distress syndrome

PURPOSES: To assess the effects of inhaled Nitric Oxide (iNO) on right ventricle dimension and function and systolic pulmonary arterial pressures in severe Acute Respiratory Distress (ARDS) due to Sars-Cov2 (COVID) infection. MATERIALS AND METHODS: We assessed the effects of iNO on right ventricle dimension and function and systolic pulmonary arterial pressures in 12 consecutive COVID-related ARDS patients by means of serial echocardiographic exams (baseline, 12 and 24 h since iNO start). RESULTS: Inhaled NO administration did not influence systolic pulmonary arterial pressures nor RV dimension and function. No changes were detectable in ventilatory data with iNO administration. Considering the negligible effect on oxygenation, iNO use was discontinued in all cases. CONCLUSIONS: In COVID-related severe ARDS iNO administrated as rescue therapy is not able to ameliorate oxygenation nor pulmonary hypertension, as assessed by serial echocardiograms. This finding may be explained by the diffuse loss of hypoxic pulmonary vasoconstriction with increased perfusion around alveolar consolidations which characterizes COVID-related severe ARDS.