Inhaled Nitric Oxide Eases COVID-19-Related Exacerbation of Pulmonary Arterial Hypertension

By Reuters Staff

May 18, 2020

NEW YORK (Reuters Health) — Outpatient inhaled nitric oxide relieved dyspnea in a patient with vasoreactive idiopathic pulmonary arterial hypertension (PAH) who developed COVID-19, researchers report.

Inhaled nitric oxide has been shown to relieve dyspnea and improve exercise tolerance in adults with PAH and other pulmonary diseases, and some studies have suggested that nitric oxide might inhibit viral replication in coronavirus-associated SARS and reduce lung inflammation.

Dr. Roham T. Zamanian from Stanford University School of Medicine in California and colleagues described the case of a 34-year-old female physician with vasoreactive idiopathic PAH who developed progressive dyspnea and fatigue following a 2-week trip to Egypt.

She was diagnosed by telehealth with COVID-19 respiratory infection and potential PAH exacerbation and was advised on supportive therapy. She expressed a desire to avoid hospitalization based on personal and public health concerns regarding the pandemic.

The healthcare team proposed that the patient might benefit from inhaled nitric oxide (iNO) treatment and, with her agreement, sought and received emergency authorization for off-label use from the FDA.

After a monitoring regimen was well established, iNO was initiated at 20 ppm, along with 2 L per minute supplemental oxygen, via nasal cannula for 12-14 hours daily, gradually (from day 13-17) weaning in stepwise doses each night over 2-3 hours.

During the 11 days following initiation of iNO, the patient was monitored remotely and experienced symptomatic relief and progressive increases in home-administered 6-minute walk test distances, according to the case report in American Journal of Respiratory and Critical Care Medicine.

Throughout the course of treatment, she did not require any urgent care, emergency department, or hospital visits.

"While the clinical improvement she experienced may not be wholly generalizable, her care represents a first step towards support for the outpatient use of iNO to treat exacerbation of PH symptoms due to COVID-19," the authors note. "This approach should not replace best clinical practices when patients present with more substantial symptoms and progressive worsening."

"While this case may serve as a proof of concept, it does not 'prove' the utility of iNO in treating respiratory manifestations of COVID-19," they add. "Well-designed clinical trials are needed to evaluate the effectiveness of iNO in the setting of COVID-19 disease. If demonstrated to be effective, outpatient iNO may serve not only to improve clinical outcomes but also to reduce the strain on inpatient resources in the current pandemic."

Dr. Zamanian did not respond to a request for comments.

SOURCE: American Journal of Respiratory and Critical Care Medicine, online May 5, 2020.