Special Safety Considerations for High Altitude Mountaineering

by Ward Hobert
Chairman
High Altitude Mountaineering Section

The High Altitude Mountaineering Section (HAMS) of The Colorado Mountain Club has loosely defined "high altitude" as being higher than the Colorado mountains. Mountaineering at such heights exposes climbers to the various forms of altitude related illnesses.

Of course, the other hazards associated with all mountain and wilderness activities are also present on climbs of high mountains. High altitude almost always makes for low temperatures, therefore frostbite and hypothermia are issues. Likewise the dangers of becoming lost or exhausted are present, and the climber may be dealing with objective hazards of technical climbing or crevasses. In remote mountains consequences of an incident involving these hazards can be much worse since rescue help may be very slow, unreliable, or totally unavailable.

The author leading a pitch on Illimani, Bolivia. Photo by Beth Slichter

Since many of the high mountains are in the third world there are significant risks of infectious disease. Attention to food and water purity and other personal hygiene habits are crucial.

Climbing teams should deal with these hazards as they do with all others. Recognize them, plan to avoid or deal with them, and have contingency plans in the event that the undesired comes to pass. Training in first aid and technical climbing is advised.

Altitude-related illness is one safety issue strongly associated with high altitude mountaineering. These maladies are a biological response to the reduced partial pressure of oxygen at high altitudes, and they may be exacerbated by dehydration, exhaustion, and low temperatures. Minor symptoms of AMS are very common and probably have been experienced by most people who have climbed a dozen Colorado 14ers. The minor symptoms can progress to more serious symptoms, and then on to the killers: high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE).

Most healthy people traveling to high altitudes can avoid altitude illness and the key is speed of ascent.

Out-of-state visitors who come to Colorado to ski typically ascend rapidly with little time for acclimatization. According to Mark Selland, M.D. with the University of Colorado Health Sciences Center in Denver, about 20% of these vacationers experience acute mountain sickness. Because Washington State's Mt. Rainier (14,410 feet) is typically climbed in only two or three days 50% to 70% of the climbers that attempt it suffer from acute mountain sickness.

In both of these cases the consequences are usually only discomfort and does not become a tragedy because the altitudes are not extreme and because those afflicted are able to get down rapidly.

However, high altitude climbers who ignore the warnings of AMS symptoms frequently come to tragic ends. The altitude does not need to be "extreme" to have extreme results.

In the fall of 1995 CMC leader Pemba Sherpa helped locate a Gamow bag for treating a French climber who was collapsed and semi-conscious at 16,600 feet on a trekker's route in Nepal. The climber was successfully evacuated afterwards. In 1993 CMCer Kevin Haight reported that one of his German climbing companions became ill and lost consciousness at the 14,500-foot Plaza de Mulas camp on Aconcagua. His life was saved by rapid treatment (Gamow bag) and immediate evacuation by mule and helicopter.

Summit photo on 21,000 foot Illimani, Bolivia. Author is on the right. Photo by Beth Slichter.

Following a few simple guidelines will prevent acute mountain sickness in most cases. The rule of thumb regarding rate of ascent is: above 10,000 feet the average rate of ascent should not exceed 1,000 feet per day. During the progression up the mountain it is good practice to hike to higher altitudes and return to lower camps for sleeping. ("Climb high, sleep low.")

Drink plenty of water. During acclimatization to high altitude the human body needs to process more water than normal. Finding the water or melting snow, and treating it or boiling it takes time and effort, but it is crucial. Consume enough water to keep urine clear, not yellow. This will require you to deal with the nuisance of frequent urination, but again, it is crucial.

Eat enough. At high altitude most people are not able to eat and process enough food; their bodies slowly dwindle away. Do your best to force yourself to eat if necessary. Consensus is that a diet high in complex carbohydrates works best.

Avoid overstressing yourself. Do not overextend yourself and become exhausted. Adjust clothing to avoid becoming overchilled. Try to get the sleep you need.

Watch yourself and others for symptoms of AMS. Typical symptoms of mild AMS are headache, nausea, sleeping problems, and fatigue. Symptoms of more advanced AMS are a headache that does not respond to aspirin, vomiting, shortness of breath that is not relieved upon resting, intense fatigue, loss of coordination, apathy, and disorientation.

If you or a member of your party experience mild symptoms, rest at your current altitude for a day. Use aspirin for headache relief. Descend if symptoms do not improve in a day or if more serious symptoms are experienced. A descent of 1,500 feet is usually sufficient to relieve symptoms. If after rest at the lower altitude all symptoms disappear it is safe to ascend again, but use caution and watch for renewed symptoms.

High camp, Nido de Condors, on Illimani, Bolivia.

A physician that specializes in travel related medicine can supply a prescription and current dosage recommendations for acetazolamide (Diamox), which is a medication that can be used prophylactically as an aid in avoiding AMS, and can also be used for treatment of minor AMS symptoms.

Gamow bags are collapsible, portable hyperbaric chambers made of fabric. A person afflicted with AMS can be placed inside of the bag and the pressure can be increased by another climber operating a foot pump. The ailing climber is then subjected to an atmospheric pressure equivalent to an altitude 1,000 feet or more lower than the actual altitude. They are lifesavers. Although they are very expensive, costing thousands of dollars, they can be rented at reasonable rates for expeditions.

There is much more to contending with altitude illnesses than can be covered in a short article such as this. Anyone seriously considering climbing to high altitudes should make an effort to learn more. There are many books dedicated to mountain-oriented medicine available at most mountain shops. The CMC Bookstore has the classic, Mountain Sickness Prevention, Recognition and Treatment by Peter Hackett available for $8.50. There are also frequent opportunities in Colorado to attend lectures by authorities in this field. (HAMS offers a high altitude mountaineering seminar each fall. One evening is devoted to high altitude illnesses and injuries.)

From Trail and Timberline, No. 915, March 1996. Used here with permission of the author.