Nitric Oxide Gas Inhalation Therapy in Spontaneous Breathing Patients With Mild/Moderate COVID-19: a Randomized Clinical Trial

To date, no targeted therapeutic treatments for the ongoing COVID-19 outbreak have been identified. Antiviral combined with adjuvant therapies are currently under investigation. The clinical spectrum of the infection is wide, ranging from mild signs of upper respiratory tract infection to severe pneumonia and death.

In the patients who progress, the time period from symptoms onset to development of dyspnea is reported to be between 5 to 10 days, and that one to severe respiratory distress syndrome from 10 to 14 days. Globally, 15 to 18% of patients deteriorates to the need of mechanical ventilation, despite the use of non-invasive ventilatory support in the earliest phases of the disease. Probability of progression to end stage disease is unpredictable, with the majority of these patients dying from multi-organ failure. Preventing progression in spontaneously breathing patients with mild to moderate disease would translate in improved morbidity and mortality and in a lower use of limited healthcare resources.

In 2004, during the SARS-coronavirus (SARS-CoV) outbreak, a pilot study showed that low dose ( max 30 ppm) inhaled NO for 3 days was able to shorten the time of ventilatory support. At the same time, NO donor compound S-nitroso-N-acetylpenicillamine increased survival rate in an in-vitro model of SARS-CoV infected epithelial cells.Based on the genetic similarities between the two viruses, similar effects of NO on SARS-CoV-2 can be hypothesized. While further in-vitro testing is recommended, we proposed a randomized clinical trial to test the effectiveness of inhaled NO in preventing the progression of SARS-CoV-2 related disease, when administered at an early stage.