High Altitude Cerebral Edema

High Altitude Cerebral Edema otherwise referred to as HACE, is a condition that usually develops from Acute Mountain Sickness (AMS). It is a direct result of the hypoxic conditions at high altitudes, it can lead to serious complications if the sufferer does not descent to lower altitudes immediately and requires immediate medical attention, however, this can be difficult as the condition has a gradual onset of approximately 2-3 days so can be difficult to spot the symptoms. If HACE is suspected you should immediately place patients in a Gamow bag as replicates lower altitude states while the patient can descent to lower altitudes to seek medical advice.

HACE may be less common than the related illness High Altitude Pulmonary Edema (HAPE) but unfortunately in most cases leads to more devastating consequences as the condition may result in permanent neurologic disability or in some cases can be fatal.

Common symptoms include:

• Emesis/Nausea
• Ataxia
• Seizures
• Severe headache
• Confusion

There are two ways in which cerebral hypoxia can result in impaired brain function these being:

• Vasogenic Oedema
• Cytotoxic Oedema

Vasogenic Oedema involves the movement of fluid into the Central Nervous System (CNS) via a leaky blood-brain barrier, ultimately leaking to a significant increase in intracranial pressure. Cytotoxic Oedema also causes an increased intracranial pressure, however, does this in a different way by the retention of fluid by cells in the CNS leading to the swelling of said cells.