Researchers at Massachusetts General Hospital (MGH) recently developed a phototherapy strategy that was highly effective in removing carbon dioxide (CO) 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,” said lead author Luca Zazzeron, M.D., a clinical fellow in anaesthesia at MGH. 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. The device works by using visible light to dissociate CO from hemoglobin, where oxygen is displaced due to CO inhalation. “We hypothesized that the exposure of blood to visible light while passing through a membrane oxygenator would increase the rate of CO elimination in vivo,” Zazzeron said. According to the study, using extracorporeal removal of CO with phototherapy (ECCOR-P) doubled the rate of CO elimination in CO-poisoned rats with normal lungs and increased the rate of CO removal by threefold compared to ventilation with 100% oxygen alone. Extracorporeal removal of CO has been effective in recent years in preventing or shortening the duration of invasive mechanical ventilation (IMV) in patients with exacerbation of chronic obstructive pulmonary disease (COPD). The implementation of phototherapy as an additional ECCOR mechanism incorporates a treatment that has been effective in a range of issues for nearly a century, including epidermal and mental conditions. “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,” Zazzeron said. For more information and to see the full study, visit https://stm.sciencemag.org/content/11/513/eaau4217.