UF Surgeons Find Bypass Technique Aids Recovery In Children With Respiratory Problems

June 9, 2003

GAINESVILLE, Fla. — A form of heart-lung bypass commonly used in newborns battling respiratory distress also benefits older children and teens experiencing lung failure caused by severe smoke inhalation, asthma and other serious conditions, University of Florida pediatric surgeons report in the June issue of the Annals of Surgery.

The technique, known as extracorporeal membrane oxygenation, or ECMO, allows injured lungs to rest and recover by filtering carbon dioxide from the blood and oxygenating it as it passes through a mechanical lung.

UF pediatric surgeons say they’ve successfully used the method to save the lives of nearly 200 infants and children who were dying of various conditions, including severe asthma, congestive heart failure stemming from a brain malformation, meningitis, viral pneumonia and inhalation or aspiration of oily liquids containing hydrocarbons, such as baby oil, lighter fluid or kerosene. The approach also has benefited patients suffering complications after lung, heart-lung and liver transplantation, and it saved all but one of the 65 newborns studied who aspirated their first bowel movement in utero.

Historically, ECMO has been widely heralded as a proven lifesaver for full-term infants whose lungs don’t function well at birth. It’s also helped babies born with a life-threatening birth defect known as congenital diaphragmatic hernia, a hole in the diaphragm muscle that enables abdominal organs such as the stomach, kidney and liver to migrate into the chest, impeding lung development.

“The take-home message here is that ECMO, which has become standard therapy for lots of newborns who have problems, is actually useful for a broad variety of problems in older children and teenagers,” said Dr. Max R. Langham Jr., a professor of surgery and chief of pediatric surgery at UF’s College of Medicine. “While not all the kids get better and survive, ECMO has clearly helped save the lives of many of our children.”

The key is to determine whether a patient’s problem is correctable and whether standard therapy with a ventilator is likely to damage the lungs beyond repair, added Langham, the paper’s lead author.

“ECMO has been used on adults since the early 1970s with a few survivors, but the survival rate is not as good as it is with babies,” he said. “What we’re suggesting in this paper is kind of an evolutionary thing, not a revolutionary thing. By selecting specific, potentially reversible problems that older children or young adults have, ECMO can be very valuable. Physicians should at least consider it.

“Babies frequently suffer from problems related to the birth process which can be reversed within a week or so, and children are more resilient and bounce back faster and better than adults do,” Langham said. “So babies are an ideal population because most of what is killing them is reversible in a fairly short period of time. In adults and children, more problems take a very long time to reverse or may not be reversible. We need to avoid using ECMO on those problems that are not reversible and learn how to get people’s lungs healed as quickly as possible in those cases that are reversible.”

For example, ECMO is not very effective at treating chronic diseases such as chronic obstructive lung disease, Langham said.

UF researchers studied data from 216 patients ages 6 weeks to 22 years who as a group were treated with 225 courses of ECMO. Overall, 81 percent of the patients recovered from their ailments. In many cases, survival after ECMO surpassed the expected survival rate associated with conventional therapies.

One patient had a severe asthma attack and was not responding to the ventilator or medications given to help him breathe, said Dr. David Kays, director of the ECMO program at Shands Children’s Hospital at UF and an associate professor of pediatric surgery at UF’s College of Medicine. ECMO kept the patient alive and let his lungs relax and heal. Within a couple days, he improved dramatically.

“It’s really a change in our thinking,” said Kays, a co-author of the paper. “The survival rate is not as good with older kids (compared with infants) – it’s more like 50 percent – but it’s certainly an improvement. When ECMO first came in the late ‘70s it was tried for adults with lung failure, and the technique was a miserable failure. And then it was used in babies with good success. Now that the technique is much better and our understanding has improved, we’re applying it back to pediatric patients and even some adult patients.”

Dr. Robert H. Bartlett, who directs the University of Michigan Extracorporeal Life Support Program, said ECMO can benefit patients who otherwise would have no alternatives.

“ECMO has been very useful in the care of older children and adults with respiratory and cardiac failure, in patients who would die without extracorporeal support,” Bartlett said.

But ECMO is best used as part of a planned escalation of therapy, not as a last-ditch resort, Kays said.

“It has to be used to treat something we think would get better within two to three weeks at the outside,” he said, adding that patients spend an average of seven days on ECMO.

Challenges remain, the UF researchers said, in part because physicians don’t yet understand enough about many lung injuries.

“The exciting part is that we’re thinking outside box,” Kays said. “That doesn’t mean that everyone should have a course of ECMO, but it is great for a handful of patients. This technology can save lives when physicians think about it early enough. We wanted to sit down and look at what we’ve learned and inform other physicians about the findings. That could save lives down the way. For the folks at home who wonder what this has to do with their lives, it’s knowing physicians are pushing the envelope to keep their loved ones alive.”