Acute Mountain Sickness (AMS)
Planning a ski trip, keen on mountain climbing or holidaying in the alps! Caution needs to be exercised when visiting areas greater than 1500m to 2000m in altitude. The reduced levels of oxygen at those heights can cause symptoms such as headaches, nausea, insomnia, vomiting, fatigue, reduced mental accuity and cyanosis. In most cases symptoms will last around 3-5 days. In very severe cases pulmonary and cerebral oedema may occur.
A high altitude is considered to be from between 1500-2000m up to 3500m, a very high altitude is between 3500m and 5500m and an extreme altitude is greater than 5500m.
Strategies for prevention
1) Hydrate - having a low blood volume reduces the body's ability to acclimatise. So make sure you are well hydrated, especially after a long flight and avoid excessive caffeine and alcohol intake.
2) Ascent slowly- if trekking, mountaineering or skiing, adding 1-2 days to the journey up can help your body to adjust to the reduced oxygen levels. A slow ascent can often prevent the onset of altitude illness.
3) Pre-existing conditions- address issues such as respiratory infections, heart conditions and chest pain as travelling to high altitudes puts stress on the cardiovascular system.
As insomnia can potentially be a problem anyone with a sleep disorder should discuss how to manage it with their doctor.
4) Preventative medicines
Preventative medicines are mostly used when a rapid ascent is unavoidable and may include:
This drug works by increasing the excretion of bicarbonate in the urine through inhibition of the carbonic anhydrase enzyme which helps prevent respiratory alkalosis which can occur at high altitudes and so is effective in preventing acute mountain illness, pulmonary oedema, and cerebral oedema.
Dexamethasone, a corticosteroid anti-inflammatory drug can also sometimes be precribed by your doctor to prevent acute mountain sickness (AMS).
5) See your doctorBe well prepared well before venturing out to a high altitude location and that includes seeing your general paractioner so that you can get the best information tailored to your individual situation.