Answer: There are at least four conditions associated with high altitude: (1) lower oxygen concentrations (available oxygen is a function of atmospheric pressure). (2) Trapped gas (air) will expand. This is what sometimes causes ear pain. (3) Definitive medical care may not be readily available. (4) Dissolved gas may leave solution (causes the "bends" or sickness in sea divers).

Even though commercial aircraft fly up to 35,000 feet, cabin pressures are usually maintained at pressures equivalent to an altitude of 6,000-7,000 feet (i.e., atmospheric pressures about 600 mm Hg compared to about 760 mm Hg at sea level). This is like traveling to some of the lower mountains near Denver. Most people have no problem with this, but emphysema or heart problems may not allow air travelers to tolerate the somewhat lower oxygen concentrations. The rapid (explosive) decompression of an aircraft cabin at 35,000 feet is a rare but serious emergency, but most passengers who immediately obtain supplemental oxygen and are secure in their seats will survive.One may encounter problems with the expansion of trapped gas in the middle ear (when the Eustachian tube is obstructed), in nasal or frontal sinuses, around a collapsed lung (pneumothorax), in a large abscess, or in the bowel (ileus). These latter problems are serious medical issues which will have presenting symptoms.If one is at 30,000 feet over the Pacific Ocean, three hours from either Los Angeles or Honolulu, then definitive medical care for any medical emergency will have to be postponed for three hours. Air travel frequently leads to such transient isolation. The dissolved gas problem is rarely significant for commercial air travel.

Now suppose a person with VHL has one or several small cerebellar hemangioblastomas and no symptoms. There is no evidence or theory to suggest that air travel will predispose such tumors to grow or bleed. If such an individual had symptoms or there were something unstable about the medical condition, then air travel might be inadvisable. Common sense should always apply, but if a slightly lower oxygen concentration and transient isolation will cause no problems, then air travel will be fine. If you are uncertain, ask your physicians if your specific condition will cause any problems with air travel.

-- James M. Lamiell, M.D., Clinical Investigations Regulatory Office, U.S. Army Medical Dept. Center and School, Fort Sam Houston, Texas

As published in the VHL Family Forum, December 1997