Most adult transplant centers require patients to walk a set distance in under six minutes to remain a good candidate for lung transplant. The thought is that if patients cannot meet this minimal threshold, then their chances of being able to rehabilitate after transplant are diminished. In pediatrics, this is also important. But Dawn Freiberger, RN, MSN, Boston Children’s Hospital’s Lung Transplant coordinator, says there are other factors that have to be considered.
“The walk test is just one piece of the pie,” says Freiberger.
In 2013, Freiberger co-authored a study, Pretransplant six-minute walk test predicts peri- and post-operative outcomes after pediatric lung transplantation, which became the precursor to a multicenter study with the Children’s Hospital of Philadelphia and St. Louis Children’s Hospital. The new study looks at how a child’s pre-transplant physical condition affects post-transplant outcomes.
“A lot of centers believe if you are not physically fit you have a lesser chance of survival,” she says. “But children are different than adults; they can be physically fit in other ways. Kids exercise without realizing they are exercising.”
“We are studying pre-transplant variables such as the ability to walk without the aid of a wheelchair or walker, whether the patient is bedbound, school attendance, whether the patient is compliant with physical therapy and the need for oxygen or any assisted ventilation,”Freiberger says.
The study also includes documentation of children on mechanical support: Have they had a tracheostomy? Are they on ECMO, which provides heart-lung bypass support? “We want to get a good picture of what these kids look like pre-transplant in terms of their mobility,” Freiberger says. “The goal is for these patients to be ambulatory while on these devices.”
The six-minute walk test is just one of many factors the investigators are documenting. Post-transplant, they are studying how many days patients spent in the intensive care unit, length of time on a ventilator and the number of days it took them to get out of bed post-transplant.
“The ultimate test is survival.”
At some adult centers, patients who can’t walk 500 feet are considered too sick for transplant and may be temporarily removed from the transplant list. Freiberger says there needs to be more research showing when a child is actually too sick.
“We are trying to figure out if there are better indicators in pediatrics by looking at all the different variables, without just saying ‘you have to be able to do ABC’ to be a transplant candidate.”
Learn more about the Boston Children’s Hospital Lung Transplant Program.