Kids climb Everest

Courtesy of Janeet Stocks

On the first day of school after spring break, nine British children had an unusual tale to tell regarding "what I did on my vacation": They climbed Mount Everest. At least part of it, that is.

Ranging in age from 6 to 13 years, the kids were part of an expedition that Janet Stocks led. As a professor of respiratory physiology at University College London, Stocks designed a study to investigate how children breathe and sleep at high altitudes. Stocks says the study will provide data on the short-term effects of high-altitude exposure in children with lung conditions, a poorly-understood subject that becomes critical when the children visit higher altitudes, or even travel by airplane.

Under blue Nepalese skies, the group hiked from Lukla to Namache Bazaar and finally to Tengboche, at 3,860 meters elevation, a round-trip journey that took three weeks. Along the way, local Sherpa guides carried the younger children who grew tired of walking, and the group distracted itself from aching feet by singing at rest stops and reciting rhymes.

The route to Tengboche is heavily hiked, beyond which the saturation of hikers thins out (Everest peaks at 8,850 m, or 29,035 ft). Adult hikers greatly outnumber children, but some kids do make the trip - the youngest to reach the summit was 17 years old - and many organizations offer family hiking packages to Tengboche. The physical effects of altitude can be felt even at Kathmandu, at 1,300 meters, but stronger symptoms that can include headache and nausea kick in at higher elevations.

The children underwent three sets of tests: the first in London (at sea level) before they left, the second at Kathmandu (1,300 m), and the last at Namache Bazaar (3,400 m). The tests included carbon dioxide and oxygen blood saturation levels, heart rate, and cerebral blood flow, as well as sleep and memory studies.

"The biggest challenge was doing these measurements in field conditions rather than an orderly laboratory," mostly because children were often "running around," says Stocks. Five adults spent nearly six hours conducting the tests on the nine children.

The sleeping tests were the most difficult. During these tests, children wore a Lycra monitoring vest while lying on wooden bunks, but they had to repeat the test if they unplugged the connections by tossing and turning during sleep. The children did toss and turn; sleep apnea is a common ailment at high altitudes, and both children and adults on the expedition reported vivid dreams and difficulty sleeping.

While Stocks anticipates that analyzing the data on the children will take until at least October, a preliminary review suggests that the children experienced good lung and blood oxygen acclimatization, and a slight short-term drop in memory at higher altitudes.

According to Anthony Mansell, pulmonary pediatrician at Rhode Island Hospital, it is generally recommended that healthy children accustomed to low altitudes should not go (and especially not sleep) above 3,000 meters. However, the kids on the expedition, termed the Young Everest Study, spent more than two weeks at higher than 3,000 meters with only minor cases of altitude sickness, Stocks says.

Although little is known about the effects of altitude on children, it's not clear how much impact this particular study will have, says Nanci Yuan, director of the pediatric pulmonary sleep lab at Lucille Packard Children's Hospital at Stanford University Medical School. For kids with impaired lung function, such as those born with underdeveloped lungs, cystic fibrosis, chronic lung failure, asthma, or neuromuscular disorders, most data stem from studies on adults, "mainly because altitude issues occur in adult people who are mountain climbers," Yuan says. This study has a better population, but it's small, and findings from healthy children may not translate to kids with lung ailments, Yuan adds. "Unfortunately in pediatric medicine you have to start small, with a small group, and go from there."

While going to Everest may seem an extreme step for the sake of science, some data just can't be obtained in a lab, says Mansell. "It's kind of hard to make children sleep in a lab with hypoxia," he notes. "Exercise and the effects of mild hypothermia have a lot to do with it." And, some things don't need a scientific justification, Mansell adds. "I think part of the idea is to go to Mount Everest and to treat these kids."