A team at Massachusetts General Hospital (MGH) has developed a new efficient, cost-effective method of producing nitric oxide (NO) from the air by an electrical spark. Inhaled nitric oxide has previously been proven as a life-saving treatment for newborns, children, and adults with certain conditions, but the high cost of the treatment and the complexity of the equipment required to administer the therapy has until now prevented its widespread adoption. Researchers at MGH, led by the physician who first discovered the efficacy of inhaled nitric oxide, have invented a lightweight, portable system to overcome these difficulties. Their discussion of the new device appears in the July 1 issue of Science Translational Medicine.
Nitric oxide is currently used to treat approximately 35,000 patients in the United States each year, including adults with pulmonary hypertension and infants suffering from persistent pulmonary hypertension of the newborn (PPHN), says Warren M. Zapol, MD, director of the MGH Anesthesia Center for Critical Care Research and emeritus chief of Anesthesia and Critical Care at the hospital, senior author of the Science Translational Medicine report. “But NO therapy is very expensive, and current systems use gas delivered in heavy tanks, making ambulatory treatment impractical. Our new system can economically make NO from the nitrogen and oxygen in the air using only small amounts of electric power. This device could enable trials of NO to treat patients with chronic lung diseases and certain kinds of heart failure and would make NO therapy available in parts of the world that don’t have the resources that are currently required.”
According to the announcement from MGH, the investigative team designed and built two prototype systems:
In one the NO generator is a separate “offline” system continually generating gas that is delivered into a ventilation system via tubing; the second “inline” system is incorporated into the ventilation system in a way that synchronizes the generation of NO during inhalation with the pulsed delivery of oxygen and other gases to be inhaled, reducing the NO that would be lost during exhalation. Since generation of NO by an electric spark can also produce the toxic gases nitrogen dioxide and ozone, along with metal fragments from the electrode, both systems use calcium hydroxide and air filters to absorb and remove those byproducts.
The study included comparisons of nitric oxide delivered via the new system and nitric oxide delivered from a tank. Although a gas mixture with 50% oxygen produced the highest concentration of nitric oxide, the amount produced from ambient air and delivered by the new system was sufficient for therapeutic use, researchers found.
“This advance has great potential for our patients,” says Richard Channick, MD, director of the MGH Pulmonary Hypertension Program, who collaborated with the research team. “If proven safe and effective, electrically generated NO therapy will greatly enhance our ability to treat many forms of pulmonary hypertension.”
For more information, see the full announcement on the MGH website.