You may not know anyone who has had a lung transplant, but that doesn’t mean they are rare or unique. In 2015 for the first time, more than 30,000 transplants were performed in the U.S., according to the U.S. Department of Health Organ Procurement and Transplantation Network. Patients with progressive lung diseases such as chronic obstructive pulmonary disease (COPD) have a high risk of acute respiratory distress syndrome (ARDS). Unable to get enough oxygen through their lungs, many patients consider a lung transplant. The waiting time for a lung transplant usually lasts about a year. During that time, life can be difficult when patients spend most of the time lying down. Whether in the hospital or at home, the patient is hooked to an artificial lung called an extracorporeal membrane oxygenation (ECMO) device that helps transfer oxygen to their blood.
Scientists at the University of Pittsburgh are developing a portable or wearable artificial lung for patients waiting for a transplant or recovering from a severe lung disease. Called a Paracorporeal Ambulatory Assist Lung or PAAL, the team has had preliminary success meeting study targets for blood oxygenation in both vitro (with organs outside a living body) and in vivo (with living specimens, in this case with sheep) for six hours. The PAAL is a combination pump and oxygenation device. It still needs to be hooked to an external tank that patients carry or push on a cart.
The next step is to test the PAAL with sheep in 5-day studies. The overall goal is to reduce the size and weight of the current PAAL design further so the wearable artificial lung and any necessary ancillary equipment fit in a backpack. Success will mean a big step forward for patients with many patients. Thanks to this work, the day is foreseeable when patients will have to spend less time in bed hooked to a large machine while they wait for a suitable lung transplant.