Altitude Sickness
Introduction
Ascending to or being at a new high altitude may cause high-altitude illness, which includes
- Acute mountain sickness (AMS)
- High-altitude pulmonary edema (HAPE)
- High-altitude cerebral edema (HACE)
While 8000 feet (2500 meters) is considered the usual threshold altitude for HAI, some persons are more sensitive to lower oxygen levels and may become ill at altitudes of 5000 to 7000 feet (1500 to 2100 meters).
- It is more likely in individuals who live close to sea level and those who have had the condition previously.
Symptoms include dizziness, headache, tachycardia and shortness of breath.
- Symptoms can begin as soon as one hour or as long as 24 hours after arriving.
Management
The best way to prevent altitude sickness is to ascend slowly.
- If you plan to travel 9800 feet (3000 m), do not increase your sleeping altitude more than 1600 feet (500 m) per day as you go higher.
The primary prophylactic medication is acetazolamide 125 mg twice daily, started the day before (preferred) or on the day of ascent; may be discontinued after staying at the same elevation for 2 to 4 days or if descent is initiated.
- Acetazolamide speeds up the process of acclimatization, but is not without side effects (polyuria, photosensitivity, taste alteration, risk of dehydration, urticaria and a possibility of severe skin rashes).
- Acetazolamide is contraindicated with a sulfa allergy.
- Higher doses are used for treatment.
NOTE: Dexamethasone may be recommended as alternative option.
In acute cases of altitude sickness, oxygen, inhaled beta-agonists and dexamethasone are given to reduce cerebral oedema.
- In severe cases, descend immediately. Aim for a descent of around 500 to 1000 meters.
Comments
Post a Comment