Second Lives for Lungs
The need for transplant organs far exceeds the available supply. With regard to lungs, about 1,400 transplants are performed each year in the U.S. However, since 1995 more than 6,000 people have died while waiting for new lungs. A recently concluded pilot project in Raleigh, NC, may offer hope for capturing more viable lungs and other organs for transplantation.
Typically lung donations come from patients who die in hospitals. However, if they have received emergency treatment or been on ventilators during their final days, their lungs may be damaged by inflammation or fluid buildup. Patients who die from cardiac arrest outside of hospitals with no such care have a higher likelihood of healthier lung tissue.
Thomas M. Egan, MD, MSc, a professor of surgery at the University of North Carolina, established through research and animal testing that because lungs self-oxygenate, they can remain viable for transplant for hours in a patient with no circulation as long as they are ventilated.
Egan received a two-year grant from the National Heart, Lung and Blood Institute to further his research. His hypothesis was if lung cells remain viable after circulatory arrest, then lungs may be suitable for transplant even if retrieved at substantial intervals after circulatory arrest and death. One research component was a proof-of-concept pilot project designed to see if potentially transplantable lungs could be transported from out-of-hospital cardiac arrest incidents by EMS crews.
According to Brent Myers, MD, MPH, director of Wake County EMS in Raleigh, Egan sought his agency’s participation because its 90,000-plus calls per year increased the chances of finding suitable patients for the study.
Egan prepared and presented a one-hour training module for EMS crews on the criteria for selection and how EMS could make a difference. No challenges arose from responders. “It really is difficult to listen to Dr. Egan for an hour without becoming a believer in the program,” Myers says.
To be considered for lung transplant harvesting, a patient had to meet all of these criteria:
• cardiac arrest that was terminated in the field;
• death not suspicious to law enforcement;
• self-designated organ donor as indicated on driver’s license.
Once resuscitation efforts had been stopped, EMS crews would leave the advanced airway in place. They would then give family members time to grieve in private, and during this time, if the patient met all criteria, the crew called Carolina Donor Services (CDS), a local organ-procurement organization.
CDS would call immediately to speak to family members about organ donation. They would get as much of the patient’s medical history as possible. After consulting with surgeons, CDS would advise the EMS crew whether the patient was a candidate.
During the four-month study, 15 patients were considered for inclusion, with two being transported as potential donors. Myers said having the self-designated organ donor as one of the criteria was key to screening patients because it made dealing with their families easier. “Not one family said no when CDS called them,” Myers says.
Egan’s research showed lungs can remain healthy for up to an hour after circulation stops, even with no outside interventions. That hour becomes the window of opportunity for the crew to contact CDS and for CDS to interact with family members. Once consent is obtained, EMS crews can begin ventilating the lungs via the airway left in place.
In the pilot, a second EMS unit was dispatched to take over ventilations from the initial crew and transport to the receiving hospital at UNC. According to Egan’s research, artificial ventilation beginning within one hour after loss of circulation can extend the time that lung tissue remains healthy and viable by an additional three hours.
While the pilot program has ended, interest remains high, and Egan is seeking further grant funding to continue this work. Another benefit of the pilot is the questions it has raised for organs other than lungs. Conversations have taken place over creating models for additional prehospital harvest/transplant screening.
“There are other organs in addition to the lungs than can be successfully transplanted, even with extended times from patient death to harvest,” Myers says. “In the pilot, if the patients failed the lung screening, no other potential organs were considered. However, based on the screening process used in this pilot, different organizations have expressed a desire to look into extended screening.”
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Ed Mund began his fire and EMS career in 1989. He currently serves with Riverside Fire Authority, an ALS-level fire department in Centralia, WA. His writing and photos have appeared in several industry publications. Contact him at email@example.com.