Most clinical trials test new drugs and medical devices within the sterile confines of a hospital or clinic, under precisely controlled conditions.

Smiths Medical chose Mount Everest.

In the past decade, the British medical device maker, with U.S. headquarters in Arden Hills, has supported a series of patient studies, some involving children, near the top of the world, testing its respiratory devices under harsh, often deadly, conditions.

Unlike typical medical technology studies, which focus on a specific device, the Everest scientists hope to find a link between critical lung diseases and the changes that occur to climbers who breathe far less oxygen at high altitudes. Smiths, a division of the London-based $3.4 billion Smiths Group, believes the research will help it invent better products to treat these diseases.

"The Everest studies have already advanced the medical community's understanding of serious conditions such as cystic fibrosis and [chronic pulmonary diseases]," said Srini Seshadri, president of Smiths Medical.

The Smiths study is part of a broader movement in medicine probing how the human body interacts with extreme environments, such as space, the ocean and Mount Everest.

In addition to Smiths' support, which has totaled about $5.6 million in the past decade, the Everest studies are being conducted in tandem with Caudwell Xtreme Everest, the largest human biology study ever performed at high altitude. The effort is being financed by the colorful British billionaire John Caudwell, who trekked to Everest Base Camp to take part in the research.

Typically, 25 percent of people who climb Mount Everest adapt quickly, 50 percent eventually adapt, and the remaining 25 percent "find it a wretched experience" and need to descend quickly, said Dr. Monty Mythen, director of research and development at the University College of London Hospitals. Mythen, who is also Smiths Medical Chair of Anaesthesia and Critical Care, is leading some of the Mount Everest research.

"On Everest, if we can understand more about what makes someone a rapid adapter, we may be able to find the switches and adapters to help the others cope," Mythen said.

The first round of research has started to bear fruit. In January, researchers published a study in the prestigious New England Journal of Medicine showing that people can function at much lower levels of oxygen than previously thought.

If sick patients can be treated at lower oxygen levels, they may experience fewer side effects. "It's possible there may be an opportunity for different ways of managing different drugs, for example," Mythen said.

At first, Mythen was a bit leery about conducting studies on the world's highest peak (the top is at 29,035 feet above sea level). "I couldn't convince myself that sending a group of doctors to the mountains to stab each others' groins [for blood samples] was money well spent," he said.

Yet Mythen, a critical-care doctor, grew more and more intrigued. "I started to read the literature, and what struck me was [that] there was only a handful of people on Everest who had been experimented on, and they were always elite athletes and climbers, totally unrepresentative of the general population," he said.

Mythen used part of his $250,000 annual endowment from the company to fund several Everest studies. "I'd never been up there, I didn't know if I could make it at Base Camp, but I thought it would be very interesting to find out," he added.

In spring 2007, Mythen and his team of doctors, physiologists and researchers opened the Smiths Medical High Altitude Laboratory at Namche Bazaar in Nepal. At 11,154 feet above sea level, the jagged outpost is the last settlement before Everest's South Col Base Camp.

The lab, which operated for three months, was equipped with donated medical equipment from Smiths, including heart and lung monitors and cardiopulmonary exercise machines. One study involved monitoring the effect of altitude on 200 "normal" adult volunteers -- including some who had pre-existing medical conditions, such as diabetes. (The Twin Cities operation, which employs about 600 people, makes infusion devices such as insulin pumps.)

Kids did their part

Perhaps the most intriguing part of the Everest experiments conducted by Mythen involved nine British children who accompanied the team to the research laboratory in 2007. Four of them were Mythen's own children, then 6 to 13 years old. Called the Smiths Medical Young Everest Study, the experiment aimed at developing new treatments for critically ill children and kids with breathing and sleep problems. The kids did well, he said: "They loved it."

Among the devices to be tested this spring is an experimental closed-circuit breathing system made by Smiths aimed at treating patients with chronic lung diseases.

The new technology is based on old technology invented by Tom Bourdillon, the late British rocket scientist. Although Edmund Hillary and Tenzing Norgay made the first successful ascent of Everest in 1953, Bourdillon nearly beat them with the help of his invention.

Seshadri, Smiths' president, said that later this year, the company will return to Everest to test a miniature version of the closed-circuit breathing apparatus.

"This has tremendous potential clinical applications for the vast majority of people with serious breathing conditions who are housebound because of the large, cumbersome devices they must use to survive," he said.

"If, as we suspect, this new device can get people up and around, that's a tremendous benefit for patients and their caregivers, as well as for the health care professionals who treat them."

Janet Moore • 612-673-7752