In May 1998, a team of Yale physicians trekked to the slopes of Mt. Everest to provide medical support for climbers and to conduct research on the body’s response to high altitude and thin air. They brought along equipment to record how fast climbers’ hearts pumped and how well their lungs worked in those extreme conditions on the world’s highest mountain.
At the core of the expedition was a system to transmit that information from climbers high on the mountain to the expedition’s makeshift medical center at the Everest Base Camp at 17,500 feet, and then around the globe to New Haven.
This spring, a second Yale team returned to Everest to continue the work of that first expedition and quickly found an opportunity to prove the value of telemedicine in an emergency. On May 14, as physicians on the mountain were beginning their daily videoconference with colleagues in New Haven, a climber stumbled into the medical tent, wheezing and coughing. The climber had reached Everest Camp Four, at 26,000 feet above sea level, before turning back with breathing difficulties that worsened even as he descended into the fuller air of lower altitudes.
Tests showed that his blood oxygen was low and that little air was moving through the lower part of his lungs. Suspecting either pneumonia or the potentially fatal condition known as high-altitude pulmonary edema, his physicians used the expedition’s electronic network to consult in real time with their colleagues in New Haven. They sent ultrasound images of the climber’s lungs, along with digitized blood smears and sputum samples, to Yale for further analysis, and the diagnosis of pneumonia was confirmed. The clinical data traveled the 15,000 miles in an instant — by satellite from Base Camp to a relay station in Malaysia, then to the United States and onto Yale via the Internet.
After two days of antibiotics, oxygen and an IV to treat dehydration, the climber left the medical tent. “He was able to walk down to lower altitudes, where he continued to improve,” said Richard Satava, M.D., of the Commercial Space Center for Medical Informatics and Technology at Yale, which was responsible for the expedition. Yale’s partners in the expedition were the Explorers Club and Millennium Healthcare Solutions Inc. Olympus America was a major sponsor of the expedition. Ronald C. Merrell, M.D., former chair of surgery, was the driving force behind the school’s telemedicine efforts.
The consultation that spanned an ocean and two continents proved the viability of the communications technology, which is being developed for the National Aeronautics and Space Administration. “We are hoping that the success of this year will be enough to encourage NASA to put some of these things on the space station and the mission to Mars,” Satava said.
The expedition’s research also expanded knowledge of the effects of hypoxia on the cardiovascular system. Previous studies concentrated on the pulmonary system, Satava said. “We now have specific measurements about how the heart and blood vessels adapt to low oxygen,” he said.
Last year’s lesson was that a telemedicine station in remote terrain could transmit to a medical center thousands of miles away, said Peter Angood, M.D., program director for the Yale Surgical Critical Care program, and a member of the support team at Yale. But during that first expedition the technology was not always successful. Personal status monitors, designed to measure climbers’ temperature, heart rate, breathing and location, often failed to transmit the information to Base Camp. This year climbers successfully repositioned repeaters, the line-of-sight devices that transmit data from the climbers’ monitors to Base Camp. Upgraded personal status monitors proved better able to transmit data to Base Camp than last year. On May 12 three climbers wore them on a trek to Camp One at 21,000 feet, while the Yale support team monitored them in real time.
Physicians on the team again opened a clinic at Base Camp, where they treated routine high-altitude ailments — headaches, insomnia and gastrointestinal disorders — as well as medical emergencies such as frostbite and physical injuries. The expedition team included a resident in ophthalmology who conducted research into the effects of high altitude on sight. “Surprisingly,” said Angood, “there is very little good research on what happens to the eyes in high altitude. With the pressure changes the contours of the eyeball itself change.” On May 18, M. Bruce Shields, M.D., chair of ophthalmology and visual science, consulted with the resident, Jennifer Grin, M.D., on a case of retinal hemorrhage. A video fundoscopic exam had revealed the hemorrhaging, and Shields also identified venous congestion in the retina.
In addition to caring for sick and injured climbers, the team’s physicians conducted regular tests on a core group of seven climbers. Every other day the climbers went through a 90-minute exam that measured, among other things, cardiac output, oxygen saturation, mental and visual acuity and cognitive functions. The tests started before the team members left the United States so their physiological measurements at sea level could be compared with readings in the mountains. The team’s medical devices included a small camera that fits under the tongue and reveals how small blood vessels change shape and caliber.
The next step in the project is, Satava said, “up in the air.” An expedition to Everest, or another remote site, depends on the results of this year’s research and the availability of corporate support. “There are other environments that similar concepts and ideas could be tested out on,” Angood said. “It doesn’t have to be Everest.”