High Altitude Cerebral Edema
High Altitude Cerebral Edema, shortened to HACE, is a potentially fatal form of AMS where the brain swells and stops functioning in the normal way. Once initiated, it can take serious hold in only a matter of hours, before most people even realise they are ill. Because of the speed at which this sets in it is vital for climbers to be aware of the signs. They include, in order of appearance:
- Changes in behaviour
- A ‘drunken stagger,’ named ataxia. The test for this, get the person to walk in a straight line without heavy boots or a backpack on flat ground. If they stumble, miss the line or fall over then treat them a HACE patient.
- Difficulty speaking
- Paralysis of a limb
- Total paralysis
Treatment is simple – immediate descent. Even if HACE starts at night descent must still be started immediately as any delay could prove to be fatal. This could be difficult because the person will be confused and staggering, and so will need people to assistthem. Descent should be to the last point when the person woke up and felt well. This is likely to be the place where the person slept two nights ago because cases of HACE generally only develop when a person with mild symptoms of AMS proceed upwards. This
should be at the least 500m. Once a lower place has been reached maximum rest is advised.
Recovery is usually possible assuming the person has descended enough in a short space of time. The drunken stagger may linger for
subsequent days, but if the symptoms eventually disappear then ascent can continue at a slower pace.