Breathe Easier: Artificial Lung May Soon Be Reality
April 26, 2001 -- Acute respiratory distress syndrome, or ARDS, will affect about 200,000 Americans this year, according to some estimates. As many as half of those people will die, often because the ventilators used to treat them can cause permanent, irreversible lung damage. But a University of Pittsburgh researcher says he is ready to begin human tests of a device that can temporarily replace damaged lungs -- and thus save lives.
ARDS is characterized by a rapid and progressive breakdown of the lungs that impairs their ability to take in oxygen. It is usually associated with the failure of other organs as well and is generally caused by trauma, infection, severe pneumonia, or shock.
Brack Hattler, MD, PhD, tells WebMD that he and his colleagues have been working on their device for 14 years and are ready to begin human testing in Europe sometime next year.
Hattler brought a group of transplant experts up to speed on the latest artificial lung technology with a speech at the International Society for Heart and Lung Transplantation meeting in Vancouver, British Columbia.
A professor of surgery at the University of Pittsburgh, Hattler says the U.S. Department of Defense first asked him to work on developing a "temporary lung" during the days leading up to the Gulf War as they were worried that Iraqi forces led would use chemical weapons against allied forces. Those toxic chemicals can cause severe lung injuries, but not permanent ones. If the lungs were given a breather and allowed to recover, Hattler says, "the damage could be reversed."
This kind of damage is very similar to what is seen in patients with ARDS. Currently patients who have this type of injury are put on a ventilator, which mechanically supplies oxygen and forces the lungs to breathe. Unfortunately, both actions can cause permanent damage.
So the goal was to develop a device that could be "easily used and could replace the lungs for a brief period of about 5 to 14 days," Hattler says. The device developed by his team works inside a vein in the leg to supply oxygen to the blood.
"What we are doing is intercepting the blood before it arrives in the lungs," says Hattler. "We can add oxygen and remove carbon dioxide while letting the lungs rest."
He explains that external controls regulate the amount of oxygen supplied as well as the rate at which carbon dioxide is vacuumed out of the blood.
Hattler says that although this device is the first major breakthrough in artificial lung technology, it does build on earlier technology.
Several years ago a venture capital company introduced the concept with IVOX, a device that supplies oxygen to the veins. That product was "actually tested in humans," says Lyle Mockros, PhD, but it was eventually abandoned when the developers ran out of money. Mockros is a professor of biomedical engineering at Northwestern University in Chicago.