High-Altitude Illness — Viva

Q1: Definition, classification & epidemiology (3 min)

• "Define high-altitude illness. At what altitude does it usually begin and why?"
• "Name and define AMS, HACE and HAPE in one sentence each. Which are benign and which are life-threatening?"
• "Which is the commonest cause of death related to altitude — HACE or HAPE?"
• "What fraction of tourists to moderate altitude (Honigman) developed AMS? What was AMS incidence at 4243 m in Hackett’s Pheriche series?"
• "Why does physical fitness NOT protect against altitude illness, and why are young fit men often over-represented?"
• "Name the chronic altitude syndromes: chronic mountain sickness (Monge disease), high-altitude pulmonary hypertension, high-altitude deterioration."^[19][21][22]

Q2: Pathophysiology (3 min)

• "Define hypobaric hypoxia. What barometric pressures did West record at 5400 m and on the Everest summit (8848 m)?"
• "Walk me through the acute ventilatory response to altitude and the role of respiratory alkalosis. How does acetazolamide act here?"
• "Describe acclimatisation over days to weeks: renal bicarbonate excretion, 2,3-BPG (do not teach a packed left/right curve shift from this page), erythropoietin, hypoxic pulmonary vasoconstriction."
• "Explain the mechanism of HACE — why is ataxia an early sign?"
• "Explain the mechanism of HAPE — what is West's hypothesis of capillary stress failure? Why is left atrial pressure normal?"
• "Why do exertion and cold precipitate HAPE?"^[23][4][3]

Q3: Clinical presentation & Lake Louise score (2 min)

• "Reproduce the 2018 Lake Louise AMS diagnostic criterion (headache plus which symptom groups). Which item was eliminated in 2018, and why?"
• "What is the cardinal sign of HACE, and the cardinal features of HAPE?"
• "What changed between the 1991 and 2018 Lake Louise scores?"
• "How does high-altitude headache differ from AMS?"^[1][19]

Q4: Differential diagnosis & pitfalls (2 min)

• "List three mimics of AMS at altitude and how you distinguish each."
• "Multiple group members wake with headache and nausea in a closed tent — what must you exclude and how?"
• "Ataxia at altitude: list three wrong explanations (drunk, tired, hypoglycaemic) and the correct one."
• "Why should diuretics not be used for HAPE (WMS 1C)?"^[3][20]

Q5: Management — prevention, AMS, HACE, HAPE (4 min)

• "State the recommended ascent schedule for prevention above 3000 m. What is 'climb high, sleep low'?"
• "Give acetazolamide: prophylactic and treatment doses, timing, mechanism, contraindications and side effects."
• "HACE: give the immediate management bundle and the dose of dexamethasone."
• "HAPE: give the immediate management bundle and the WMS nifedipine regimens. When, if ever, is a PDE-5 inhibitor used, and why must it not be combined with nifedipine? What is the WMS grade for salmeterol prevention?"
• "What is a portable hyperbaric chamber used for in HAPE/HACE? Why must it not delay descent?"
• "When can a patient resume ascent after recovery from HACE or HAPE?"^[3][11][26]

Q6: Special populations, evidence & regional practice (2 min)

• "Keyes 2023: is altitude exposure an absolute restriction in uncomplicated pregnancy? What numeric sleeping-altitude cut-off does WMS 2019 give (none)? What does WMS say about ginkgo in pregnancy?"
• "A patient with sickle cell trait asks about an altitude trip — what is your advice and why?"
• "Summarise the Wilderness Medical Society 2019 guideline's three most important recommendations."
• "What is the operational approach to acclimatising troops to high altitude (staged ascent, medical posts) — and why must a 2700–3000 m band not be cited to Roach 2018?"
• "Name the Bärtsch 1991 NEJM nifedipine trial (not Maggiorini 1991) and Maggiorini 2006 tadalafil/dexamethasone trial, with the HAPE counts."^{[3][11][26][28]}

References28ShowHide

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