Summiting Success and Acute Mountain Sickness on Mount Kilimanjaro

Mount Kilimanjaro is the highest mountain in Africa and a popular tourist destination. Because it is easy to access and is a commonly attempted summit, this mountain is frequently attempted by persons with little mountaineering experience and no technical climbing ability. As such, and because of the rapidity with which it can be ascended by trekkers, it is also the site of many cases of acute mountain sickness (AMS).

Andrew Davies and colleagues published an article entitled "Determinants of Summiting Success and Acute Mountain Sickness on Mt Klimanjaro (5895 m)" in Wilderness and Environmental Medicine, volume 20, pages 311-317, 2009. The purpose of their study was to determine the incidence of AMS, the frequency of summiting success and the factors that affected these in trekkers on Kilimanjaro. In their study, 312 trekkers were measured for various physiological parameters and the Lake Louise Score, which is a measure of AMS. Out of the 312 trekkers, 181 complete sets of data were collected.

Seventy-seven per cent of the 181 trekkers developed AMS and 61% of the trekkers attained the summit. Trekkers who used acetazolamide (Diamox) were more likely to attain the summit and less likely to suffer AMS than were those who did not use acetazolamide. This was a factor on the five-day route, but not on the 4-day route. The authors concluded that the risk for developing AMS is high on Kilimanjaro. Their opinion was that while it appears to be beneficial to take an extra day to ascend and to take acetazolamide (both of these to improve acclimatization and thus diminish the incidence of AMS), it makes most sense to use a more gradual ascent profile for climbing Kilimanjaro. Such a route (Western Breach Route) is available, and requires 6 or more days for the ascent, as opposed to the Marango route, which was utilized during this study.

It makes perfect sense to take longer to ascend and/or to use acetazolamide, which is well known to decrease the incidence of AMS in susceptible individuals. Why do people rush to the top? No doubt, this is to accommodate busy schedules and to keep down expenses. What is the cost of this haste? It is likely the discomfort and risks of AMS, as well as the possibility that after all of that effort, one might not only become ill, but not attain the summit.