At-Home Use of Inhaled Nitric Oxide for Pulmonary HTN Complicated by COVID-19

A recently published report describes the case of a 34-year-old female patient with idiopathic pulmonary arterial hypertension (iPAH) who was diagnosed with coronavirus disease 2019 (COVID-19) and managed with inhaled nitric oxide (iNO) in the outpatient setting. 

The patient, who had recently returned from a 2 week trip to Egypt, sought medical care after experiencing anosmia as well as a low-grade fever. After being informed by her county health authority that she had tested positive for COVID-19 5 days later, the patient contacted her PAH care center for a telehealth assessment.

The patient’s vasoreactive iPAH was typically managed with nifedipine (60mg extended-release daily), tadalafil, and macitentan. Despite taking her medications as directed, the patient reported experiencing dyspnea on exertion, significant fatigue, and WHO III symptoms during her telehealth evaluation. Her vital signs were as follows: temperature, 98.9℉; heart rate, 90 bpm; blood pressure, 88/57mmHg; oxygen saturation (SpO2), 97% on room air. Supportive therapy was initiated after the patient was diagnosed with potential PAH exacerbation due to COVID-19 respiratory infection. 

After expressing her desire to avoid hospitalization, a home-based telehealth care plan was developed. This plan included twice-daily reporting of her vital signs, SpO2 values, and 6-minute walk test (6MWT) results as well as completion of the EmPHasis-10 (E10), a health-related quality of life questionnaire, once daily. 

“Given the patient’s symptoms and underlying preserved vasoreactivity we proposed that she might benefit from iNO treatment,” the authors reported. An emergency investigational new drug application for off-label use of iNO was submitted and accepted by the Food and Drug Administration. Genosyl® (Vero Biotech), a tankless iNO delivery system, was delivered to the patient’s residence and equipment setup assistance was provided remotely. 

The patient began receiving supplemental oxygen in addition to 20 ppm iNO for 12-14 hours per day, which was gradually weaned stepwise every night over 2-3 hours. Because the patient began experiencing symptomatic relief and increases in her 6MWT over the next 11 days, iNO was gradually weaned and eventually discontinued. 

“This patient was remotely managed by clinicians, and was more amenable (as a physician herself) to self-monitoring and self-directed therapy than the ordinary patient,” the authors pointed out. They added, “This is not a typical case, 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.”

Although successful in this case, the utility of iNO for the treatment of respiratory manifestations due to COVID-19 is not necessarily proven. Because of this, clinical trials should be completed to evaluate the efficacy of iNO in the management of COVID-19.

Reference

Zamanian RT, Pollack Jr CV, Gentile MA, et al. Outpatient inhaled nitric oxide in a patients with vasoreactive IPAH and COVID-19 Infection [published online May 5, 2020]. American Journal of Respiratory and Critical Care Medicine. doi: 10.1164/rccm.202004-0937LE.