MBBS OSCE · General Medicine

OSCE — High-Altitude Illness

Eight-minute OSCE station on High-Altitude Illness: focused history, examination priorities, investigations, emergency and definitive management.

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NEET-PGINICETUSMLEPLAB

Brief (to candidate)

You will assess a patient with a presentation consistent with High-Altitude Illness.
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.[3]

Clinical context

High-altitude illness is the spectrum of syndromes caused by ascent to altitude (usually above 2500 m) under hypobaric hypoxia: (1) Acute Mountain Sickness (AMS) — common and self-limiting, defined as headache plus one or more of nausea/anorexia, fatigue/weakness and dizziness/vertigo (the 2018 Lake Louise score eliminated disturbed sleep); (2) High-Altitude Cerebral Oedema (HACE) — severe, with ataxia and altered consciousness from vasogenic cerebral oedema, fatal if untreated; (3) High-Altitude Pulmonary Oedema (HAPE) — severe, with exertional dyspnoea, dry then pink-frothy cough, cyanosis and reduced exercise performance from uneven hypoxic pulmonary vasoconstriction and non-cardiogenic pulmonary oedema. Prevention is slow ascent (above 3000 m, sleeping elevation not more than 500 m per day, rest day every 3 to 4 days) with acetazolamide 125 mg every 12 h for rapid itineraries; descent (or oxygen) is mandatory in HACE and HAPE.[1][3][19]

Candidate tasks

  1. Clarify onset, severity, associated features, and red-flag symptoms.
  2. State focused examination priorities.
  3. List first-line investigations and any named score/criteria.
  4. Give immediate resuscitation steps.
  5. Outline definitive management with doses/routes where standard.
  6. Name complications and disposition (ward / HDU / theatre / discharge safety-net).
  7. Mention one special-population modifier (pregnancy, child, elderly, CKD).[3]

Examiner checklist

DomainPass behaviours
DefinitionCorrect working diagnosis language
AssessmentFocused, prioritised, red flags sought
InvestigationsAppropriate first-line + interpretation
Emergency careABC / time-critical actions first
Definitive careSpecific drugs/procedures, not generic phrases
SafetyHeadache plus nausea/fatigue after ascent above 2500 m - acute mountain sickness
SafetyAtaxia (heel-to-toe gait) or altered consciousness at altitude - HACE; immediate descent plus oxygen plus dexamethasone
SafetyExertional dyspnoea, cough (pink frothy), cyanosis, reduced exercise performance — HAPE; immediate descent plus oxygen

Model outline

Lead with the working diagnosis and life threats. Resuscitate before definitive tests when unstable. Use WMS 2019 therapy with named agents and doses (acetazolamide 125 mg every 12 h prophylaxis; AMS treatment 250 mg every 12 h; HACE dexamethasone 8 mg then 4 mg every 6 h; HAPE nifedipine 30 mg ER q12h or 20 mg ER q8h as adjunct only). Descent is mandatory for HACE and HAPE. Document escalation criteria and follow-up. A safe candidate is specific, structured, and never delays descent for non-urgent imaging.[3][9][12]

References28Show
  1. [1]Roach RC, Hackett PH, Oelz O, et al. The 2018 Lake Louise Acute Mountain Sickness Score High Alt Med Biol, 2018.PMID 29583031
  2. [2]Gallagher SA, Hackett PH. High-altitude illness Emerg Med Clin North Am, 2004.PMID 15163571
  3. [3]Luks AM, Auerbach PS, Freer L, Grissom CK, Keyes LE, McIntosh SE, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update Wilderness Environ Med, 2019.PMID 31248818
  4. [4]Bärtsch P, Mairbäurl H, Swenson ER, et al. High altitude pulmonary oedema Swiss Med Wkly, 2003.PMID 12947525
  5. [5]Maggiorini M. High altitude-induced pulmonary oedema Cardiovasc Res, 2006.PMID 16904089
  6. [6]West JB. Recent Advances in High Altitude Medicine and Biology High Alt Med Biol, 2015.PMID 25961356
  7. [7]Gianfredi V, Albano L, Basnyat B, Ferrara P. Does age have an impact on acute mountain sickness? A systematic review J Travel Med, 2020.PMID 31897482
  8. [8]Maggiorini M. Prevention and treatment of high-altitude pulmonary edema Prog Cardiovasc Dis, 2010.PMID 20417343
  9. [9]Stream JO, Grissom CK. Update on high-altitude pulmonary edema: pathogenesis, prevention, and treatment Wilderness Environ Med, 2008.PMID 19099331
  10. [10]Wang J, et al. Comparative effects of pharmacological interventions for the prevention of acute mountain sickness: a systematic review and Bayesian network meta-analysis Travel Med Infect Dis, 2025.PMID 40383249
  11. [11]Bärtsch P, Maggiorini M, Ritter M, et al. Prevention of high-altitude pulmonary edema by nifedipine N Engl J Med, 1991.PMID 1922223
  12. [12]Faisal MU, et al. High-altitude cerebral edema in a non-climber at the K2 Base Camp: a case report Cureus, 2025.PMID 41531575
  13. [13]Fischer R, et al. Acute mountain sickness: how can it be treated and how can it be avoided? Internist (Berl), 2014.PMID 24522556
  14. [14]Zhou X, et al. Life destiny of erythrocyte in high altitude erythrocytosis: mechanisms underlying the progression from physiological (moderate) to pathological (excessive) high-altitude erythrocytosis Front Genet, 2025.PMID 40242475
  15. [15]Wani AH, et al. Magnetic resonance neuroimaging findings in high-altitude cerebral edema (HACE) and probable correlation with its temporal evolution and pathogenesis Niger Med J, 2025.PMID 41169831
  16. [16]Bultas J. Mountain sickness Cas Lek Cesk, 2015.PMID 26750624
  17. [17]Deshwal R, et al. Nifedipine for the treatment of high altitude pulmonary edema Wilderness Environ Med, 2012.PMID 22441082
  18. [18]Bates MG, et al. Sildenafil citrate for the prevention of high altitude hypoxic pulmonary hypertension: double blind, randomized, placebo-controlled trial High Alt Med Biol, 2011.PMID 21962063
  19. [19]Fiore DC, et al. Altitude illness: risk factors, prevention, presentation, and treatment Am Fam Physician, 2010.PMID 21121556
  20. [20]Foutch RG, et al. Carbon monoxide poisoning at high altitudes Am J Emerg Med, 1988.PMID 3178954
  21. [21]Honigman B, Theis MK, Koziol-McLain J, et al. Acute mountain sickness in a general tourist population at moderate altitudes Ann Intern Med, 1993.PMID 8452324
  22. [22]Hackett PH, Rennie D, Levine HD. The incidence, importance, and prophylaxis of acute mountain sickness Lancet, 1976.PMID 62991
  23. [23]West JB, Lahiri S, Maret KH, Peters RM Jr, Pizzo CJ. Barometric pressures at extreme altitudes on Mt. Everest: physiological significance J Appl Physiol Respir Environ Exerc Physiol, 1983.PMID 6863078
  24. [24]Gao D, Wang Y, Zhang R, Zhang Y. Efficacy of Acetazolamide for the Prophylaxis of Acute Mountain Sickness: A Systematic Review, Meta-Analysis and Trial Sequential Analysis of Randomized Clinical Trials Am J Med Sci, 2021.PMID 33587912
  25. [25]Low EV, Avery AJ, Gupta V, Schedlbauer A, Grocott MP. Identifying the lowest effective dose of acetazolamide for the prophylaxis of acute mountain sickness: systematic review and meta-analysis BMJ, 2012.PMID 23081689
  26. [26]Maggiorini M, Brunner-La Rocca HP, Peth S, et al. Both tadalafil and dexamethasone may reduce the incidence of high-altitude pulmonary edema: a randomized trial Ann Intern Med, 2006.PMID 17015867
  27. [27]Sartori C, Allemann Y, Duplain H, et al. Salmeterol for the prevention of high-altitude pulmonary edema N Engl J Med, 2002.PMID 12023995
  28. [28]Keyes LE, Sanders L. Pregnancy and Exercise in Mountain Travelers Curr Sports Med Rep, 2023.PMID 36866950
OSCE — High-Altitude Illness · MBBS OSCE · NeetVellum