Nitric oxide is a gas with a pretty enviable medical resume.
Its discovery gave rise to a treatment that snatches thousands of "blue babies" — newborns starved of oxygen by a heart defect — from the jaws of death every year. Later, research into the gas's knack for relaxing blood vessels led to the development of the world's best-known little blue pill — the erectile dysfunction drug Viagra.
In 1992, the journal Science named nitric oxide "molecule of the year." And in1998, UCLA pharmacologist Louis J. Ignarro shared a Nobel Prize in medicine for uncovering nitric oxide's role as a "signaling molecule in the cardiovascular system.”
Nitric oxide may not be done yet. The colorless, odorless gas, inhaled through a mask or even from a small "flute," is now being tested as an experimental treatment for COVID-19. It may also prove helpful in protecting healthcare workers on the front line of the pandemic from getting sick.
At hospitals in Boston, Alabama, Louisiana, Sweden and Austria, researchers have launched a clinical trial to test inhaled nitric oxide in patients with mild to moderate cases of COVID-19. The trial will test whether the gas can drive down the number of patients who end up needing breathing assistance from a mechanical ventilator, a piece of equipment that's in critically short supply.
For about 30 minutes two or three times a day, study participants assigned to the trial's active arm will inhale a high dose of nitric oxide through a mask. A control group will go without the gas.
In Italy, where the gas was used under more haphazard conditions, the treatment appeared to dramatically boost oxygen levels in the blood of COVID-19 patients, said Dr. Lorenzo Berra, the critical-care specialist at Massachusetts General Hospital who is leading the new trial. But it'll take more rigorous testing to clarify how much nitric oxide helps, he said.
A proposed second trial, still under scrutiny by a research panel at Massachusetts General Hospital, would enroll healthcare workers who are routinely exposed to patients with COVID-19 and are themselves at high risk of infection. For 10 to 15 minutes at the start and end of every shift, doctors and nurses would tug on a handheld device and inhale a high dose of nitric oxide.
