Scientists have invented a way to help patients breathe without actually breathing - by injecting oxygen directly into the blood.
Patients who are unable to breathe, for instance due to lung failure, sometimes need another way to get oxygen into their blood to prevent cardiac arrest and brain damage.
Now a team at Boston Children's Hospital says it might have the answer.
The researchers have created small, gas-filled microparticles which can be injected directly into the blood, and the hope is they will be able to restore blood-oxygen levels to normal "in seconds".
The particles are made of fatty molecules surrounding tiny packets of oxygen gas.
In the latest issue of Science Translational Medicine, John Kheir, MD, of the Department of Cardiology at Boston Children's Hospital, said animal trials had proven successful.
In some cases the animals were kept alive for 15 minutes without a single breath.
"This is a short-term oxygen substitute - a way to safely inject oxygen gas to support patients during a critical few minutes," he said.
"Eventually, this could be stored in syringes on every code cart in a hospital, ambulance or transport helicopter to help stabilize patients who are having difficulty breathing."
"Some of the most convincing experiments were the early ones," he added.
"We drew each other's blood, mixed it in a test tube with the microparticles, and watched blue blood turn immediately red, right before our eyes."
Similar attempts to infuse the blood with oxygen directly were tried in the 1900s, but were abandoned because they failed to work and often led to gas embolisms.
"We have engineered around this problem by packaging the gas into small, deformable particles," Kheir said. "They dramatically increase the surface area for gas exchange and are able to squeeze through capillaries where free gas would get stuck."Suggest a correction