Advice
on Altitude Sickness for Trekkers
The
Cause of Altitude Sickness
More
and more people are taking High altitude holidays. In South
America crossing Andean passes often means you can reach heights
above 4000 metres. Trekkers in the Himalayas near Nepa reach
similar heights also and Kilimanjaro in Tanzania and Mount
Kenya are more than 5000 metres. Only healthy and trained
people should attempt these expeditions, and if you are in
any doubt you should take medical advice. Anyone can get acute
mountain sickness during rapid ascent if you stay for more
than twelve hours above 2500 metres. Altitude sickness affects
all ages including children when the symptoms in them are
more difficult to recognise.
The
difference in altitude over a 24 hour period is the determining
factor. From 3000 metres and higher, this risk increases when
the altitude difference between encampments exceeds 300 metres.
High Altitude Definitions
High
Altitude:
2400m to 3658m. (e.g. Cochabamba in Bolivia = 2550m. Bogota
in Colombia = 2645m. Quito in Ecuador = 2879m. Cuzco in Peru
= 3225m)
Very
High Altitude:
3658m to 5500m. (La Paz in Bolivia = 3658m. Lhasa in Tibet,
China = 3685m. Base camps of Everest in Nepal = 5500m)
Extreme
Altitude:
5500m to 8848m (e.g. the summit of Mount Everest).
The Signs of Mountain Sickness
The
early warning signs of acute mountain sickness usually include
nausea, headache, anorexia and insomnia. If you get vertigo,
vomiting, apathy, staggering and dyspnoea occur, immediate
accompanied descent from the mountain is essential. If you
don't descend immediately it may be fatal.
Prevention of Altitude Sickness
You
must avoid ascents of greater than 300 metres every day if
starting from above 3000 metres. If early signs of mountain
sickness appear it is best to rest for a day at the same altitude.
If these symptoms persist or increase you must descend at
least 500 metres. Acetazolamide is sometimes used as prophylaxis
for mountain sickness when a gradual ascent cannot be guaranteed.
This should not be used as an alternative to a gradual ascent.
This chemical acts on acid-base balance and stimulates respiration.
It should be combined with a sensible fluid intake. You should
not use this for young children.
Treatment of Altitude Sickness
Minor
Symptoms
Simple analgesis (eg: paracetamol) for headaches. Sleeping
pills should be avoided if possible. Seek medical advice.
Serious
or Persistent Symptoms
Evacuation or descent; oxygen if available. Seek urgent medical
advice but do not let this delay your descent - steroid drugs
and/or nifedapine if necessary.
Useful
Website
Information sheets are available to Doctors/Climbers/Trekkers
contact the British
Mountaineering Council. |
