Elsevier

The Lancet

Volume 361, Issue 9373, 7 June 2003, Pages 1967-1974
The Lancet

Seminar
High-altitude illness

https://doi.org/10.1016/S0140-6736(03)13591-XGet rights and content

Summary

High-altitude illness is the collective term for acute mountain sickness (AMS), high-altitude cerebral oedema (HACE), and high-altitude pulmonary oedema (HAPE). The pathophysiology of these syndromes is not completely understood, although studies have substantially contributed to the current understanding of several areas. These areas include the role and potential mechanisms of brain swelling in AMS and HACE, mechanisms accounting for exaggerated pulmonary hypertension in HAPE, and the role of inflammation and alveolar-fluid clearance in HAPE. Only limited information is available about the genetic basis of high-altitude illness, and no clear associations between gene polymorphisms and susceptibility have been discovered. Gradual ascent will always be the best strategy for preventing high-altitude illness, although chemoprophylaxis may be useful in some situations. Despite investigation of other agents, acetazolamide remains the preferred drug for preventing AMS. The next few years are likely to see many advances in the understanding of the causes and management of high-altitude illness.

Section snippets

Epidemiology

The most important risk factors for the development of high-altitude illness are rate of ascent, altitude reached (especially the sleeping altitude), and individual susceptibility. The rate of AMS among conference delegates to moderate altitudes (1920–2957 m) in Colorado, USA, was 25%.2 In the Mount Everest region of Nepal, about 50% of trekkers who walk to altitudes higher than 4000 m over 5 or more days develop AMS,3, 4 and 84% of people who fly directly to 3860 m are affected.5 High-altitude

Clinical presentation

AMS is characterised by non-specific symptoms and a paucity of physical findings. The main symptoms are headache, anorexia, nausea, vomiting, fatigue, dizziness, and sleep disturbance, but not all need to be present. Headache is deemed the cardinal symptom, but the characteristics are not sufficiently distinctive to differentiate it from other causes of headache.20 Symptoms of AMS typically appear 6–12 h after arrival at high altitude. Diagnostic signs are absent, and the presence of abnormal

Clinical presentation

HAPE typically occurs in the first 2–4 days after arrival at altitudes higher than 2500 m, and is not necessarily preceded by AMS. Risk factors for HAPE are the same as for AMS and HACE. In addition, HAPE may be over-represented in men compared with women, and cold is a risk factor.85 People with abnormalities of the cardiopulmonary circulation that are associated with increased pulmonary blood-flow pressure, such as unilateral absence of a pulmonary artery or primary pulmonary hypertension, or

Search strategy and selection criteria

We undertook a computer-aided search of PubMed, and used the key words altitude, acute mountain sickness, high-altitude pulmonary edema, high-altitude pulmonary oedema, high-altitude cerebral edema, high-altitude cerebral oedema, hypoxia, and mountaineering. We also reviewed journal reference lists and abstracts from international scientific meetings, and used our existing knowledge of primary publications in the field. Priority was given to recent reports covering topical issues and

References (135)

  • CS Houston et al.

    Cerebral form of high altitude illness

    Lancet

    (1975)
  • J Maloney et al.

    Plasma vascular endothelial growth factor in acute mountain sickness

    Chest

    (2000)
  • IA Mórocz et al.

    Volumetric quantification of brain swelling after hypobaric hypoxia exposure

    Exp Neurol

    (2001)
  • P Bärtsch et al.

    Sumatriptan for high-altitude headache

    Lancet

    (1994)
  • M Burtscher et al.

    Ibuprofen versus sumatriptan for high-altitude headache

    Lancet

    (1995)
  • Y Matsuzawa et al.

    Nocturnal periodic breathing and arterial oxygen desaturation in acute mountain sickness

    J Wilderness Med

    (1994)
  • RT Ross

    The random nature of cerebral mountain sickness

    Lancet

    (1985)
  • JF Kasic et al.

    Treatment of acute mountain sickness: hyperbaric versus oxygen therapy

    Ann Emerg Med

    (1991)
  • R Naeije et al.

    High-altitude pulmonary edema with primary pulmonary hypertension

    Chest

    (1996)
  • P Vock et al.

    Variable radiomorphologic data of high altitude pulmonary edema: features from 60 patients

    Chest

    (1991)
  • G Cremona et al.

    Pulmonary extravascular fluid accumulation in recreational climbers: a prospective study

    Lancet

    (2002)
  • O Oelz et al.

    Nifedipine for high altitude pulmonary oedema

    Lancet

    (1989)
  • World health statistics annual 1995

    (1996)
  • B Honigman et al.

    Acute mountain sickness in a general tourist population at moderate altitudes

    Ann Intern Med

    (1993)
  • DR Murdoch

    Altitude illness among tourists flying to 3740 meters elevation in the Nepal Himalayas

    J Travel Med

    (1995)
  • RC Roach et al.

    Exercise exacerbates acute mountain sickness at simulated high altitude

    J Appl Physiol

    (2000)
  • JS Milledge et al.

    Acute mountain sickness susceptibility, fitness and hypoxic ventilatory response

    Eur Respir J

    (1991)
  • AJ Pollard et al.

    Children at high altitude: an international consensus statement by an ad hoc committee of the International Society for Mountain Medicine, March 12, 2001

    High Alt Med Biol

    (2001)
  • RC Roach et al.

    How well do older persons tolerate moderate altitude?

    West J Med

    (1995)
  • DR Murdoch et al.

    Acute mountain sickness in the Southern Alps of New Zealand

    NZ Med J

    (1998)
  • B Basnyat

    Neck irradiation or surgery may predispose to severe acute mountain sickness

    J Travel Med

    (2002)
  • DR Murdoch

    Symptoms of infection and altitude illness among hikers in the Mount Everest region of Nepal

    Aviat Space Environ Med

    (1995)
  • TA Cumbo et al.

    Acute mountain sickness, dehydration, and bicarbonate clearance: preliminary field data from the Nepal Himalaya

    Aviat Space Environ Med

    (2002)
  • E Silber et al.

    Clinical features of headache at altitude: a prospective study

    Neurology

    (2003)
  • B Basnyat et al.

    Acute medical problems in the Himalayas outside the setting of altitude sickness

    High Alt Med Biol

    (2000)
  • PH Hackett

    High altitude cerebral edema and acute mountain sickness: a pathophysiology update

    Adv Exp Med Biol

    (1999)
  • RC Roach et al.

    Frontiers of hypoxia research: acute mountain sickness

    J Exp Biol

    (2001)
  • P Bärtsch et al.

    Acute mountain sickness and high-altitude cerebral edema

  • LG Moore et al.

    Low acute hypoxic ventilatory response and hypoxic depression in acute altitude sickness

    J Appl Physiol

    (1986)
  • P Bärtsch et al.

    Enhanced exercise-induced rise of aldosterone and vasopressin preceding mountain sickness

    J Appl Physiol

    (1991)
  • ER Swenson

    High altitude diuresis: fact or fancy

  • I Singh et al.

    Acute mountain sickness

    N Engl J Med

    (1969)
  • Y Matsuzawa et al.

    Cerebral edema in acute mountain sickness

  • PH Hackett et al.

    High-altitude cerebral edema evaluated with magnetic resonance imaging: clinical correlation and pathophysiology

    JAMA

    (1998)
  • JA Krasney

    Cerebral hemodynamics and high altitude cerebral edema

  • RA Fishman

    Brain edema

    N Engl J Med

    (1975)
  • W Mayhan et al.

    Role of veins and cerebral venous pressure in disruption of the blood-brain barrier

    Circ Res

    (1986)
  • BD Levine et al.

    Dynamic cerebral autoregulation at high altitude

    Adv Exp Med Biol

    (1999)
  • L Schilling et al.

    Mediators of cerebral edema

    Adv Exp Med Biol

    (1999)
  • F Xu et al.

    Rat brain VEGF expression in alveolar hypoxia: possible role in high-altitude cerebral edema

    J Appl Physiol

    (1998)
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