UF/Duke Researchers Show Lung Transplantation May Be Option For Certain Ventilator-Dependent Patients
GAINESVILLE, Fla.—It’s one of medicine’s greatest ironies: The patients who most need a certain treatment may be too ill to handle it. Now University of Florida and Duke University researchers say one group of people long considered too sick for a lung transplant may be able to undergo the procedure after all.
Many surgeons have shied away from suggesting transplantation to those whose lung disease is so severe they can breathe only with the help of a ventilator. That’s because on average such patients do face a higher risk of dying in the first couple of months after surgery.
New research, however, suggests that some of them actually can handle transplants just as well as their counterparts who haven’t been on ventilators. The scientists reported their findings, which could renew hope for dozens of patients, in the January issue of the journal Chest.
For a select population of patients who are medically stable and rely on a ventilator, transplantation can offer a clear and significant survival benefit and improved quality of life, said pulmonologist Dr. Maher A. Baz, an assistant professor of medicine at UF’s College of Medicine.
“We should carefully consider some select stable patients who are ventilator-dependent for referral for lung transplantation, rather than automatically ruling them out,” Baz said.
Nationwide, nearly 3,700 patients are on the lung transplant waiting list, according to the United Network for Organ Sharing. Each year, about 850 actually receive a transplant. About 3 percent of recipients are dependent on a ventilator at the time of transplant. Studies have shown a threefold increase in the risk of death by the end of the first year after surgery in these patients compared with recipients who did not receive ventilation.
In recent years, lung transplantation has become an acceptable option for patients with end-stage lung diseases, Baz said. Strict criteria are used to select which patients are good candidates and surgical techniques have improved. Physicians also have grown more adept at caring for these patients after surgery.
Even so, patients on ventilators have frequently been told that transplantation is not an alternative. Aside from their increased risk of death soon after the operation, they are prone to developing pneumonia. In addition, the long-term immobility and bed rest associated with ventilator dependency can weaken respiratory muscles, prolonging time spent on the ventilator after transplant and delaying recovery.
Between 1992 and 1997, the research team studied nine ventilator-dependent patients who were medically stable and able to exercise with a physical therapist’s help. (These patients could walk or exercise while using a mobile ventilator or a small bag that an attendant squeezed so they could breathe.)
All had end-stage lung disease: emphysema, pulmonary fibrosis, cystic fibrosis or bronchiecstasis. In addition, the bacteria in their lung secretions were not resistant to antibiotics, as is sometimes the case. The patients had spent anywhere from 13 days to five years on a ventilator prior to the transplant. Most were on about six months.
Researchers compared the group with 65 people who were not dependent on a ventilator at the time they received a transplant in 1997. The scientists found the groups had similar one-year survival rates, 78 percent versus 83 percent. The lung function at one year also was similar.
“For patients on a ventilator, especially patients on a ventilator for more than a week, we’d expect their prognosis (without a transplant) would be dismal,” said Dr. Scott M. Palmer, medical director of Duke’s lung transplant program. “Many patients with advanced lung disease don’t come off a ventilator and never survive. It is unlikely that any of the patients in our series would have survived to one year or longer without a transplant, and whatever time they had left would have been miserable. We offered a great benefit to them in terms of quality of life, and potentially, survival.”
The only difference between the two groups was that people who were on the ventilator before surgery spent an average of 40 days on the ventilator recovering after the transplant, a month longer than those in the other group, said Baz, who collaborated with Dr. Mark Staples, surgical director of UF’s lung transplant program, and other colleagues at Duke.
Researchers speculated that the patients fared better than those tracked by the national transplant registry in part because they were medically stable. The registry, on the other hand, includes ventilator-dependent transplant recipients who are more critically or acutely ill at the time of surgery.
“I wouldn’t want people to get the impression that everyone with bad lungs on a ventilator, especially for more than a few weeks, can get a transplant,” Palmer said. “These were people who had single-organ dysfunction… their kidneys, hearts and livers were still working quite well. They were extremely motivated and despite being on a ventilator performed significant amounts of rehab, like riding a stationary bike or walking on a treadmill in their hospital room. I think that’s why they did well — they maintained their physical conditioning.”
Baz said the findings will have to be replicated in a larger study before widespread recommendations can be made.
“This gives us data to say it’s worth looking at in a larger study,” he said. “And it starts moving us away from thinking if you’re on a mechanical ventilator we can’t do a transplant.”