One of our expedition’s primary goals is to expand the knowledge of medical science pertaining to high altitude medicine. Last year team members Larry Rigsby, M.D., and Eric Meyer, M.D., performed a sleep study at 21,000 feet on the North Col route of Everest (Tibet). Drs. Rigsby and Meyer compared sleep patterns of a western climber and a climber from the Sherpa tribe of Nepal. The Sherpa live at a higher altitude than any other people in the world, often above 4,000 meters (13,500 feet), and their skill as mountaineers is legendary. To our knowledge this was the highest sleep study or polysomnography done in the field to date.

This year we plan to monitor a group of western climbers and Sherpas. In collaboration with the Department of Hypertension and Vascular Biology at the University of Alabama School of Medicine, we are designing a study to test the effects of altitude on blood levels of ANP and BNP (natriuretic peptides) and Endothelin (a vasoconstrictor), which contribute to the onset of pulmonary hypertension. Pulmonary hypertension begins when tiny arteries in the lungs become narrow or blocked. This causes increased resistance to blood flow in the lungs, which in turn raises pressure within the pulmonary arteries. As the pressure builds, the heart’s right ventricle must work harder to pump blood through the lungs, eventually causing the heart to weaken and sometimes to fail completely.

We intend to measure the ANP, BNP and Endothelin levels in climbers’ blood at increasing altitudes, and also to compare the difference between western climbers and Sherpas. We hope this information will give us additional insight into physical adaptation at altitude, and especially insight into the onset and development of high altitude pulmonary edema (HAPE), an often-fatal form of altitude sickness. For additional information, please review our medical section at www.everestnews.com

Of course, climbing Mt. Everest will also be an “experiment of one” for every climber on Team No Limits. We will be monitoring and testing ourselves as we reach and surpass limits we have never known. This is part of the challenge of climbing Everest!