High altitude cerebral edema

(Redirected from HACE)


  • Also known as HACE
  • Progressive neurologic deterioration in someone with acute mountain sickness or HAPE (due to ↑ ICP)
  • Almost never occurs at <8,000ft

Clinical Features

Differential Diagnosis

High Altitude Illnesses


Head CT of HACE showing diffuse effacement of cerebral sulci and compression of ventricles.
  • Typically a clinical diagnosis

Expected SpO2 and PaO2 levels at altitude[1]

Altitude SpO2 PaO2 (mm Hg)
1,500 to 3,500 m (4,900 to 11,500 ft) about 90% 55-75
3,500 to 5,500 m (11,500 to 18,000 ft) 75-85% 40-60
5,500 to 8,850 m (18,000 to 29,000 ft) 58-75% 28-40


High altitude management algorithm.
  • Immediate descent is the treatment of choice
  • If descent not possible use combination of:
    • Supplemental O2 (goal SpO2 90%)[2]
    • Supportive hyperventilation
    • Dexamethasone 8mg initially (PO, IM, or IV), then 4mg q6hr
    • Acetazolamide 250mg BID (better as ppx)
    • Hyperbaric bag (Gamow bag) if available


See Also


  1. Gallagher, MD, Scott A.; Hackett, MD, Peter (August 28, 2018). "High altitude pulmonary edema". UpToDate. Retrieved May 2, 2019.
  2. Hackett PH, Roach RC. High altitude cerebral edema. High Alt Med Biol 2004; 5:136-146.