Acute altitude illnesses

This summary is based on a recent BMJ review:

Acute altitude illnesses include:

- high altitude headache
- acute mountain sickness
- high altitude cerebral edema
- high altitude pulmonary edema

Typical scenarios in which such illness occurs include:

- a family trek to Everest base camp in Nepal (5,360 m)
- a fund raising climb of Mount Kilimanjaro (5,895 m), shown in the map below
- a tourist visit to Machu Picchu (2,430 m)


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High altitude headache and acute mountain sickness often occur a few hours after arrival at altitudes over 3,000 meters.

Occurrence of acute mountain sickness is reduced by slow ascent. Severity can be modified by prophylactic acetazolamide.

Mild to moderate acute mountain sickness usually resolves with:

- rest
- hydration
- halting ascent
- analgesics

Occasionally people with acute mountain sickness develop high altitude cerebral oedema with confusion, ataxia, persistent headache, and vomiting.

Severe acute mountain sickness and high altitude cerebral edema require urgent treatment with:

- oxygen if available
- dexamethasone
- possibly acetazolamide
- rapid descent

High altitude pulmonary edema is a rare but potentially life threatening condition that occurs 1-4 days after arrival at altitudes above 2,500 meters. Treatment includes oxygen if available, nifedipine, and rapid descent to lower altitude.

What do extreme athletes who can summit the peaks of Mt. Everest have in common with people with heart failure? This Mayo Clinic video explains it:



References:

Clinical Review: Acute altitude illnesses. BMJ 2011; 343:d4943 doi: 10.1136/bmj.d4943
High-Altitude Medicine http://buff.ly/UGjp6Q