Health • Simulated flights in hyperbaric chamber test current guidelines.
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The emergency room at Intermountain Medical Center (IMC) in Murray is the busiest in Utah, and one of the more common injuries treated there in about 1 in 20 patients is a collapsed lung, or pneumothorax.
It's a treatable problem; many resolve on their own under observation, said Sarah Majercik, a trauma surgeon at IMC. Some require the insertion of a tube or needle to remove air that, after a blunt or penetrating chest injury, builds up in the chest and puts pressure on the lung.
But it can be a hardship for patients, who under current medical guidelines, are told to wait at least two weeks to fly due to the risk of the air expanding and further compressing the lung.
Observational research led by Majercik, however, casts doubt on those guidelines much to the relief of skiers injured in Utah while on vacation.
"A significant portion of our trauma population does not live in Utah, especially during ski season," said Majercik. "Two weeks is a long time, and a financial burden, for a vacationer to wait to return home."
The guidelines, promoted by the Aerospace Medical Association and embraced by the Federal Aviation Administration, date back to 2003 and had never been objectively tested.
The expansion of air at high altitudes is a real phenomenon, which theoretically could have disastrous consequences for pneumothorax patients, said Majercik, noting it could lead to pulmonary distress or a heart attack, which flight crews aren't equipped to handle.
But until now "no one had ever tested" the likelihood of that happening, she said.
For her study, recently submitted for publication in an academic journal, Majercik used a hyperbaric chamber to simulate a flight at 8,400 feet, the typical cruising height for an airliner. Ten traumatic pneumothorax patients who had been treated by chest tube or high flow oxygen therapy sat in the chamber at this "altitude" for two hours.
A nurse took the patients' vital signs every 10 minutes and questioned them about symptoms, and a radiology technician took a chest x-ray at the conclusion of the flight for comparison to a "pre-flight" x-ray.
Each of the 10 subjects successfully completed the two-hour flight. And despite a slight increase in the pocket of air outside their lung, they showed no cardiorespiratory symptoms while at altitude.
The study addresses an important question, said Mark Elstad, a pulmonologist at University Hospital and Clinics and the Department of Veterans Affairs Medical Center in Salt Lake City.
"We simply don't have the data to know if it is safe for these patients to fly with a residual pneumothorax," he said, "or how long the patient should wait to fly after pneumothorax treatment."
Doctors tend to heed consensus guidelines recommending waiting for two weeks to fly after a pneumothorax resolves, recognizing they are conservative, he said.
"In one small study, patients who flew within four days of pneumothorax following needle lung biopsy did so without significant problems," Elstad said.
But each patient is different, he added, noting young, healthy individuals tolerate lung injuries better than those with underlying health problems.
The IMC study "may provide more evidence that it is safe to fly sooner that we currently recommend," he said.
Majercik has also tested a second group of 10 patients at 12,650 feet "to make study more applicable to people living at sea level," she said. She's still analyzing data from that second phase.
But she's optimistic that her findings "will help to change recommendations that doctors make to patients."