Acute Mountain Sickness
From Anvita Health Wiki
Contents |
Etiology
- acute ascent of lowlanders to > 7000 feet
Physiology
- PiO2 decreased by 4-5 mm Hg for every 1000 feet in elevation
- high-altitude induced hypoxia increases minute ventilation & decreased pCO2
- hemoglobin concentration increases secondary to diuresis
- transient increase in erythropoietin levels
History
- travel to above 1900 meters, 6300 feet
- history of previous acute mountain sickness
Clinical-manifestations
- symptoms occur 6-90 hours after ascent
- lethargy
- insomnia
- headache
- ataxia
- nausea/vomiting
- anorexia
- dyspnea
- cerebral edema in severe cases
Management
- acetazolamide 125 to 250 mg BID prophylactically
- start 1 day before ascent
- continue for 2 days after reaching destination [3]
- rest, hydration
- supplemental oxygen & dexamethasone for cerebral edema
- return to lower elevation
- patient education:
- advise cardiac & elderly patients to take extra precautions; patients who are stable at sea level may not be at high altitudes
- advise against exercise above 5000 feet until acclimation for patients with:
- unstable angina
- uncontrolled arrhythmias
- poorly controlled heart failure
- advise staying < 8000 feet for patients with
- severe heart failure
- angina pectoris
- valvular heart disease [3]
- atrial fibrillation can be exacerbated at high altitudes due to hypoxia & tachycardia
- consider increasing rate-control med if patients are rapidly ascending over 5000 feet [3]
More General Terms
References
- Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 764
- Medical Knowledge Self Assessment Program (MKSAP) 14, American College of Physicians, Philadelphia 2006
- Prescriber's Letter 17(2): 2010 Moving On Up: Altitude and Your Cardiac Patients Detail-Document#: [1] (subscription needed) [2]
