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Incidence of acute mountain sickness in UK Military Personnel on Mount Kenya
  1. Antonia Hazlerigg1,2,
  2. DR Woods1,3,4 and
  3. AJ Mellor1,3,5
  1. 1Defence Medical Services, Royal Centre for Defence Medicine, Birmingham Research Park, Birmingham, UK
  2. 2Department of Emergency Medicine, Royal Infirmary Edinburgh, Edinburgh, UK
  3. 3Carnegie Institute of Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
  4. 4Department of Medicine, Royal Victoria Infirmary, Newcastle Hospitals NHS Foundation Trust, Newcastle, UK
  5. 5Academic Department of Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, UK
  1. Correspondence to Maj Antonia Hazlerigg, Department of Emergency Medicine, Royal Infirmary Edinburgh, Old Dalkeith Road, Edinburgh EH16 4SA, UK; ahazlerigg{at}


Background Acute mountain sickness (AMS) is a common problem of trekkers to high altitude. The UK military train at high altitude through adventurous training (AT) or as exercising troops. The ascent of Point Lenana at 4985 m on Mount Kenya is frequently attempted on AT. This study sought to establish the incidence of AMS within this population, to aid future planning for military activities at altitude.

Methods A voluntary questionnaire was distributed to all British Army Training Unit Kenya based expeditions attempting to ascend Mount Kenya during the period from February to April 2014. The questionnaire included twice daily Lake Louise and Borg (perceived exertion scale) self-scoring. All expeditions were planned around a 5-day schedule, which included reserve time for acclimatisation, illness and inclement weather.

Results Data were collected on 47 participants, 70% of whom reached the summit of Point Lenana. 62% (29/47) self-reported AMS (defined as Lake Louise score (LLS) ≥3) on at least one occasion during the ascent, and 34% (10/29) suffered severe AMS (LLS ≥6). Those who attempted the climb within 2 weeks of arrival in Kenya had a higher incidence of AMS (12/15 (80%) vs 17/32 (53%), p=0.077). Participants recording a high Borg score were significantly more likely to develop AMS (16/18 vs 9/21, p=0.003).

Conclusions This represents the first informative dataset for Mount Kenya ascents and altitude. The incidence of AMS during AT on Mount Kenya using this ascent profile is high. Adapting the current ascent profile, planning the ascent after time in country and reducing perceived exertion during the trek may reduce the incidence of AMS.


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  • Contributors AH: first draft methods, data collection, first draft and rewrites in consultation. AJM: review of methods, statistics and advice for rewrites. DRW: general advice for study design, review of statistics and figures and advice for rewrites.

  • Competing interests None declared.

  • Ethics approval Royal Centre for Defence Medicine.

  • Provenance and peer review Not commissioned; externally peer reviewed.