Nitric Oxide Could Ease COVID-19 Pulmonary Consequences

Inhaled nitric oxide (NO) could contribute to better clinical outcomes and alleviate the rapidly rising strain on healthcare capacity, according to a new study.

The study, by researchers at George Washington University (GW, Washington, DC, USA) and the Albert Einstein College of Medicine (New York, NY, USA), reviews the rationale for exogenous NO use during the pandemic, since it is known as an antimicrobial and anti-inflammatory molecule with key roles in pulmonary vascular function in the context of viral infections and other pulmonary diseases. During the severe acute respiratory syndrome (SARS) outbreak in 2003, NO was used to inhibit viral replication by cytotoxic reactions via intermediates such as peroxynitrite.

NO plays key roles in maintaining normal vascular function and regulating inflammatory cascades that contribute to respiratory diseases, when excessively activated in the context of declining endothelial function. Vasculature depleted of NO suffers from persistent inflammation and blunted delivery of oxygen and removal of toxic byproducts through stagnant blood flow into and out of hypoxic tissue. NO supplementation could help prevent cytokine storm, restoring the functional capillary density crucial for oxygen delivery and waste removal.

When acute respiratory distress syndrome (ARDS) is already present, NO improves arterial oxygenation and blunts pulmonary hypertension by dilating pulmonary vessels in ventilated lung parenchyma. These supportive changes at the physiologic level may translate to decreased ventilator support, improved density of lung infiltrates on chest radiography, improved kidney function, and therapeutic benefits after the discontinuation of NO. The study was published on July 15, 2020, in Nitric Oxide.

“With the emergence of COVID-19 as a pandemic with the ability to overwhelm the body and our health care infrastructure, patients have a pressing need for effective agents that can slow the disease in their bodies and in their communities,” concluded co-senior author Professor Adam Friedman, MD, of the GW department of dermatology, and colleagues. “Exogenous NO for targeted patient populations may be a treatment that can reduce viral load in the lungs, prevent the chain of events that rapidly destabilizes patients to ARDS, and promote clinical recovery from ARDS.”

Related Links:
George Washington University
Albert Einstein College of Medicine