What is HACE

What is High Altitude Cerebral Edema (HACE)?

Altitude illness is a general term referring to the three problems that can occur on ascent to altitude: Acute Mountain Sickness (AMS), High Altitude Cerebral Edema (HACE), and High Altitude Pulmonary Edema (HAPE).

AMS and HACE are considered a spectrum of the same altitude illness. The small amount of swelling in the brain that contributes to mild AMS becomes significant swelling and progresses to severe headache, confusion, lethargy, lack of coordination, irritability, vomiting, seizures, coma, and eventually death if untreated. A person with HACE may look like a confused, disoriented drunk person, fumbling with clothing, unable to walk a straight line, and with slurred speech.

How do you diagnosis HACE?

The Lake Louise Criteria for HACE requires a change in mental status and ataxia (unsteady gait) in a person with a recent ascent to high altitude.

How often do people get HACE in Colorado?

While HACE is a life-threatening illness, travelers very rarely get it in Colorado. HACE usually occurs at altitudes over 13,000 ft (4000 m). Early symptoms of headache and AMS precede the more life threatening symptoms of HACE, and treatment of AMS prevents progression to HACE.. In Colorado, HACE is only seen in conjunction with high altitude pulmonary edema (see below). This is not the case in other areas of the world such as the Himalayas where the altitude is much higher.

Am I at risk for HACE?

Any condition that takes up space in the brain such as a brain tumor, hydrocephalus, or recent bleeding increases the risk for HACE as there is less room for brain swelling.

How do I prevent HACE?

Preventive measures are the same as for AMS.

  • Ascend slowly.
  • Drink a little extra water.
  • Avoid heavy exertion the first 1-2 days.
  • Avoid alcohol or medications that reduce your breathing drive.
  • Acetazolamide speeds up acclimatization and prevents HACE as well as AMS.

How do you treat HACE?

  • A person with HACE MUST go down to a lower altitude. Oxygen therapy should be started if available
  • Dexamethasone, a steroid medication can improve HACE symptoms.
  • If a person cannot descend due to weather or other conditions, then hyperbaric therapy with a Gamow bag or other hyperbaric bag should be initiated, if available.