Monday, May 7, 2012

Kilimanjaro and Hypoxia

Kilimanjaro rises to 5,895 meters (19,340 ft) where the amount of oxygen available for breathing is about half that relative to the surrounding plains of Tanzania.  At altitude the air we breathe becomes progressively thinner.  About half the atmosphere of the earth is within 18,000 ft of the surface - the remaining half is spread in a ever diminishing concentration out to about 100 miles above the surface of the earth.  Humans and altitude typically do not mix well.  Some of our hardier folk live above 10,000 ft, around the great mountain ranges of the world, but they are a distinct minority.  The problem is we tend to get sick at high altitude, especially if we live at low altitude then ascend too fast or stay high too long. 

Charles Houston spent a lifetime researching mountain sickness, which is caused primarily from a lack of oxygen or hypoxia.  Charlie should know all about hypoxia:  he was the leader of two American teams to attempt climbing K2, the second highest mountain in the world at over 28,000 ft.  Both attempts on either side of World War II were unsuccessful but the attempt in 1953 achieved fame for the self-less acts of all climbers involved in the fatal expedition.  The team became known as the brotherhood of the rope and is the subject of numerous mountaineering articles. After this last expedition, Charlie retired from mountaineering and spent a lifetime studying the physiological effects of hypoxia from a number of institutions, including the University of Vermont, where he was a Professor of Medicine.  His article in Scientific American on hypoxia is a great read [1].

One of the physiological effects of hypoxia includes an increased flow of blood to the brain, which creates a local accumulation of fluid and pressure leading to headaches and impeded judgement.  I experienced this on my climb on Kilimanjaro at about 14,000 ft at the famed Lava Tower after a day of about 4,000 ft elevation gain.  This particular day of my trek was carefully arranged by our guides to allow for acclimatization, which helps the body adjust to elevation gain.  The physiological effects include an up-regulation of the hormone erythropoietin to stimulate the production of red blood cells and allow for oxygen to be carried around the body more efficiently.  This important acclimatization step certainly helped with me being able to summit Kilimanjaro without ill effects.  For more on this adventure and some great photographs, please go to the SLAS Electronic Laboratory Nieghborhood.

Peculiar image of a table setting for 1 for lunch that we passed on our way to Kilimanjaro's Lave Tower (background).

1. Houston, C. S. 1992. "Mountain sickness." Scientific American, October, pp. 34-9

By, BioTek Instruments

By: BioTek Instruments

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