NEW YORK (Reuters Health) -
People with severe obstructive
sleep apnea taking commercial airline flights may be at greater
risk of adverse events from stress on the heart than healthy
people, researchers warned at the American Thoracic Society's
2008 meeting in Toronto.

Obstructive sleep apnea, or OSA, occurs when soft tissues
in the airways collapse during sleep and temporarily block
breathing. This can happen dozens of times an hour, leading to
daytime sleepiness and eventually to increases in blood
pressure.

In a study, Leigh M. Seccombe, of Concord Repatriation
General Hospital in Sydney, Australia, found evidence that
patients with OSA may experience higher heart rates and
increased bodily need for oxygen during flights compared with
healthy people.

Seccombe and her colleagues compared oxygen levels in the
blood and ventilation rates in 10 healthy people and 22 people
with severe OSA during simulated flight conditions replicating
the oxygen and air pressure levels experienced during
commercial flights.

“It is normal for the rate of breathing to increase when
air pressure falls,” Seccombe explained in a statement. “We
found that (for patients with OSA) their breathing intensity
increases at about the same rate as it does in healthy people.”

However, the physiological stress and demand for oxygen was
increased in people with OSA.

“In short, the work they do to run the core range of body
functions (heart, lungs, brain) is much greater under cabin
conditions,” said Seccombe, who is currently part of a group
working on guidelines that will help doctors decide whether
their patients are at risk from air travel.

“We addressed OSA because it is becoming so much more
common as obesity increases and there are greater numbers of
obese passengers on commercial flights,” Seccombe said.

If the results of the current study are typical, “half of
the patients with OSA would require supplemental oxygen
in-flight if current guidelines (for those with lung disease)
were strictly followed,” she noted.