Could nasal nitric oxide help to mitigate the severity of COVID-19?

A recent article in the Elsevier Journal authored jointly by scientific researchers from Universities and hospitals in Taiwan, USA and France examines the roles played by the nose and mouth in facilitating nitric oxide as a possible treatment for respiratory distress such as COVID-19.

Nasally inhaled nitric oxide (NO) has been used as a rescue treatment to improve arterial oxygenation against acute respiratory distress syndrome. It was used in 2002-2003 during the SARS epidemic with benefits for patients including improved arterial oxygenation, decreased pulmonary hypertension and reduced spread and density of lung infiltrates.

NO is produced in the para-nasal sinuses. It diffuses into the airways and lungs where it dilates blood vessels and airways. This can result in lower blood pressure and easier breathing.

NO also facilitates the removal of dust and viral particles from the respiratory tract. It produces antimicrobial effects against a broad range of microbes including bacteria and viruses which may help prevent pulmonary infections.

Importantly and in the context of COVID-19, NO inactivates viruses by modifying proteins and nucleic acids that are essential for viral replication.

In humans, higher base levels of exhaled NO are associated with fewer symptoms of the common cold, suggesting that nasally produced NO represents one of the body’s endogenous defence mechanisms against viruses in the airways.

Mouth breathing reduces NO levels in the airways and also deprives the body of the filtering, warming and humidifying effects produced by nasally inhaled air.

Anecdotal observations suggest that sealing the mouth with adhesive tape while sleeping# reduces common colds by permitting nasal breathing to increase NO levels in the airways and decrease the viral load during sleep and allow the immune system more time to mount an effective antiviral response.

[#As a Breathing retrainer using the Buteyko method I do not recommend simply taping the mouth without first having prepared for this by first ensuring the nose is clear and free from blockages and then by carrying out the recommended breathing exercises including practising mouth taping during the day. Many people simply breathe too much air and at too fast a rate to simply switch to taped nasal breathing while sleeping. Often dysfunctional breathers are anxious and there is a risk that attempting to convert to exclusive nasal breathing without properly preparing for this change of habit can exacerbate the levels of stress and anxiety which may be currently experienced. In conclusion please consider this anecdotal observation as one that has merit but which should only be followed with proper guidance.]

Please read the full article

Microbes and Infection