High dose inhaled nitric oxide gas (iNO) is a safe and effective respiratory therapy for pregnant women hospitalised with severe COVID pneumonia, resulting in faster weaning from oxygen and shorter hospital stay, according to a study published in Obstetrics & Gynecology. Massachusetts General Hospital (MGH) researchers reported that the addition of twice-daily nitric oxide to standard of care oxygen therapy decreased the respiratory rate of pregnant women with low oxygenation levels of the blood without causing any side effects.
“To date, very few respiratory treatments to complement supplemental oxygenation in COVID pregnant patients have been tested,” explained the study’s senior author, Lorenzo Berra, MD. “Investigators from all four medical centers that participated in our study agreed that administration of high dose nitric oxide through a snug-fitting mask has enormous potential as a new therapeutic strategy for pregnant patients with COVID.”
Pneumonia triggered by COVID is particularly threatening to pregnant women since it may quickly progress to hypoxaemia, requiring hospitalisation and cardiopulmonary support. “Compared to non-pregnant female patients with COVID, pregnant women are three times more likely to need intensive care unit admission, mechanical ventilation, or advanced life support, and four times more likely to die,” noted lead author Carlo Valsecchi, MD. “They also face a greater risk of obstetric complications such as preeclampsia, preterm delivery, and stillbirth.”
Nitric oxide is a therapeutic gas that was initially approved by the U.S. Food and Drug Administration in 1999 for inhalation treatment of intubated and mechanically ventilated newborns with hypoxic respiratory failure. With MGH driving many early studies, iNO in high concentrations was also shown to be effective as an antimicrobial in reducing viral replication of SARS-CoV-1 and, more recently, SARS CoV-2. During the first wave of COVID, MGH treated six non-intubated pregnant patients with iNO at high doses of up to 200 parts per million (ppm). Favourable outcomes with iNO led MGH clinicians to offer this treatment to other pregnant patients, and motivated the present study.
Researchers and clinicians from multiple departments in four hospitals – including critical care medicine, respiratory care, and maternal foetal medicine – studied 71 pregnant patients with severe COVID pneumonia admitted to these hospitals, 20 of whom received iNO200 twice daily. The study found that iNO therapy at this dosage, when compared to standard of care alone, resulted in reductions in the need for supplemental oxygen and in hospital and ICU lengths of stay. No adverse events related to the intervention were reported in either mothers or their babies.
“Being able to wean patients from respiratory support quicker could have other profound implications, including reducing stress on women and their families, lowering the risk of hospital-acquired infections, and relieving the burden on the health care system,” noted Dr Berra. “Above all, our study supports the safety of high dose nitric oxide in the pregnant population, and we hope more physicians will consider incorporating it into carefully monitored treatment regimens.”
Source: Massachusetts General Hospital
