Investigators at Massachusetts General Hospital (MGH; Boston, MA) have developed a phototherapy strategy that is highly effective for removing carbon monoxide (CO; a toxic, colorless, and odorless gas produced by cars, trucks, fires, and explosions) in rats and improving the animals' health.
"Whenever CO intoxication is associated with lung injury, current treatment with pure oxygen is ineffective and sometimes even dangerous. If the development of our technology for larger animals and humans will be successful, this may represent a unique alternative treatment for CO-poisoned individuals with concurrent lung injury," says Luca Zazzeron, MD, a clinical fellow in anesthesia at MGH and the lead author of their paper that describes the work.
The strategy relies on the knowledge that inhaled CO reduces the capacity of blood to carry oxygen by displacing oxygen from the blood's hemoglobin, and that visible light can break the molecular bond between CO and hemoglobin. As described in their paper, the researchers developed a device that combines phototherapy with a "membrane oxygenator"—an artificial membrane that allows oxygenation of the blood and removal of CO when blood is passed through it—and they tested the device in a rat model of CO poisoning, with and without lung injury.
Compared with ventilation with 100% oxygen, the addition of CO removal with phototherapy doubled the rate of CO elimination in CO-poisoned rats with normal lungs. In CO-poisoned rats with lung injury, this treatment increased the rate of CO removal by threefold compared with ventilation with 100% oxygen alone, and more animals that were treated in this way survived.
"Although additional studies are required, in the future, soldiers, firefighters, and civilians exposed to CO may benefit from early treatment with CO removal and phototherapy, in particular those individuals with concurrent lung injury," says Zazzeron.
Full details of the work appear in the journal Science Translational Medicine.