Incidence and predictors of acute mountain sickness among trekkers on Mount Kilimanjaro

Abstract

Stewart J. Jackson, James Varley, Claudia Sellers, Katherine Josephs, Lucy Codrington, Georgina Duke, Marina A. Njelekela Gordon Drummond, Andrew I. Sutherland, A. A. Roger Thompson, J. Kenneth Baillie. Incidence and predictors of acute mountain sickness among trekkers on Mount Kilimanjaro. High Alt. Med. Biol. 217–222, 2010—. We investigated the incidence of AMS amongst a general population of trekkers on Mount Kilimanjaro, using the Lake Louise consensus scoring system (LLS). Additionally we examined the effect of prophylactic acetazolamide and different ascent profiles. Climbers on 3 different ascent itineraries were recruited. At 2743m we recruited 177 participants (mean age 31, range [18-71]) who completed LLS together with an epidemiological questionnaire. At 4730m participants (n¼189, male¼108, female¼68, mean age 33, range [1871]) completed LLS, 136 of whom had been followed up from 2730 m. At 2743 m, 3% (5/177) of climbers were AMS positive, and 47% (89/189) of climbers from all itineraries were AMS positive at 4730m. Of climbers attempting the Marangu itineraries, 33% (45/136) were taking acetazolamide. This group had a similar rate of AMS and no statistical difference in severity of LLS when compared with those not taking prophylactic drugs. We also did not demonstrate a difference between the incidence of AMS in climbers who did or did not take a rest day at 3700 m. However, there was a significant reduction in the incidence of AMS amongst pre-acclimatized subjects. Consistent with previous work, we found that the rate of AMS on Mount Kilimanjaro is high. Furthermore, at these fast ascent rates, there was no evidence of a protective effect of acetazolamide or a single rest day. There is a need to increase public awareness of the risks of altitude sickness and we advocate a pragmatic ‘‘golden rules’’ approach (http://www.altitude.org/altitude_sickness.php).