Essay: HAPE & HACE Lee Meyers, MD - Basecamp Fri, April 27, 2001 4:05AM
The most important one bit of knowledge to remember about high altitude medicine is that ALL illnesses get better at lower altitude. You are now a high altitude medical genius!
When acclimatizing to altitude, there are useful important shifts in body fluids. Unacclimatized climbers can have harmful shifts in body fluids into lung or brain tissues, which can endanger their lives. These are know as: HAPE (High Altitude Pulmonary Edema,) and HACE (High Altitude Cerebral Edema) both of which are life threatening, but will improve at lower altitudes.
HAPE occurs when fluid shifts into the alveoli or air sacs of the lungs, thereby reducing oxygen to the climber. Early stages of HAPE cause a dry cough and shortness of breath, especially lying down. Late stages lead to cyanosis and a cough, productive of frothy, sometimes blood-tinged sputum. In the late stage, the climber can literally drown in his own fluids.
HACE occurs when fluid shifts into the tissues of the brain. Early stages mimic Acute Mountain Sickness, causing headache, nausea, lethargy, and sleeplessness. Symptoms of HACE can rapidly progress, within hours to death. Late symptoms include disorientation, visual changes including blindness, abnormal behavior or hallucinations, inability to walk (ataxia), seizures and other CNS dysfunctions.
The treatment for both HAPE & HACE is rapid descent at least 2000-3000 ft. or until symptoms resolve. Descent must be immediate and should not wait till morning. To gain some time for the descent some drugs can be given. For HAPE, nefedipine can be given orally to help reduced the fluid in the lungs and oxygen is a must. For HACE, dexamethasone, a powerful steroid, is given by injection or orally to reduce the pressure in the brain. Neither drug is a replacement for rapid descent.
Another useful method to gain some time for the descent is the use of the Gamow Bag, a portable pressure chamber. The patient is placed completely within the airtight chamber and by means of a foot-pump, the barometric pressure is raised inside the bag, effectively lowering the patient's altitude by 6-8000 ft. Constant pumping, about every 5 seconds is required to maintain the pressure and refresh the air. The patient is usually kept in the bag for 2-3 hours before being rechecked, although a window in the top of the bag allows visual observation and communication. This process can be continued as long as foot-power is available. Improvement with the Gamow Bag is only temporary, giving time for the descent. Climbers with serious symptoms of HAPE or HACE should not return to high altitude soon after.
All of our high altitude climbers have acclimatized well and none have developed symptoms of HAPE or HACE. But several members of other expeditions have needed our help to treat their climber who have had either HAPE or in one case a couple of days ago of a climber at ABC who had a severe case of HACE, which required large doses of dexamethasone and the Gamow bag several times before moving him down the mountain to Kathmandu and home. He was very close to dying from HACE.
Descent is always a proper response to medical problems at altitude!!