ExplorersWeb in-depth series:  Altitude, Oxygen, and AMS

Introduction to Altitude, its effects on the body, and AMS - Acute Mountain Sickness

You find yourself awake in a teahouse along the path to Everest, cold, and shivering.  All night long it has been difficult to sleep and you attempt to roll on your side in search of yet another position that might appease Hypnos into granting you a half an hour of some shuteye.  Five, six seconds go by and you notice that your buddy sleeping next to you has yet to take a breath.  For five more seconds you lay there not sure about the situation.  Now panicking you reach over and give him a huge shove hoping to evoke a movement, or a breath, or anything for that matter.  “What the . . . !”  He’s alive, breathing, and now a little upset at you.  Fortunately for him, he is dead asleep within a couple of seconds. 

The interrupted breathing that happened to the friend is called Cheyn-Stokes breathing, a rather common occurrence when a person is at high altitude.  A decrease of oxygen in the atmosphere gives signals for a body to start acting in a certain way and can ultimately hurt or even kill.  Cheyn-Stokes is not dangerous, however, it is just one example of the body’s reaction to the oxygen-starved air.  At the summit of Mount Everest,  air pressure  is 66% less than at sea level. 

When a person goes higher and does not allow enough time for their body to adjust to the thin air, he or she can get sick or even die.  The general term for altitude induced illness is AMS – Acute Mountain Sickness.  Reactions vary from person to person and there is no effective way of ruling out those who are most at risk.  For some, a flight to a Colorado ski resort from New York City will yield symptoms of AMS.  Others trek all the way to Everest Base Camp at 17,000 feet with nary a headache.  The latter being an unlikely story, the point is that everyone is susceptible regardless of age, sex, or health.  However, it has been observed that people develop a ‘memory’ for altitude – having been all ready to a higher elevation, the body is better prepared the next time and the symptoms are less prevalent. 

One rule of thumb if you are at altitude and are sick, there is a 99.9% chance that it has something to do with the elevation.  A general guide is that above 10,000 feet you should not gain more than 1,000 feet per day and should take a rest day every 3,000 feet.  However, this is not law and the decision to move or rest essentially comes down to how you feel and how severe your symptoms are.    

·       Normal acclimatization
Some headache (relieved by aspirin), irregular breathing at night, rapid breathing at day, increased urine output.

·       Moderate mountain sickness
Some sleeplessness, decreased urine output, persistent headache not relieved by aspirin. Stay at your current altitude for some time (1-2 days) until you feel well. Don’t climb higher!

·       Acute mountain sickness (AMS)
Dizziness, vomiting, losing your balance, persistent coughing, sleepiness. Go down at least 500-m/1500 ft! Immediately.  Consult a doctor (on the walkie-talkie) and take emergency medicine.  

The most serious illnesses at altitude are HACE and HAPE.  HACE is high altitude cerebral edema – the swelling of the brain.  HAPE is high altitude pulmonary edema – fluid build up in the lungs.  Both of these are extreme and very deadly if not treated.   

The name of the game is to gain altitude a little at a time giving time to adjust.  Climbers acclimatize themselves by progressively climbing higher in smaller steps, spending time there, and then descending to recuperate.  The body becomes progressively adjusted to the increases.  This takes time to do and some push it too far by not listening to all the warning signs their bodies give them.  If it’s screaming at you with throbbing headaches, don’t ascend, regardless of any pressures by your goals and your peers, life is much more important. 

AMS should be treated with respect.  Remember, you can always come back and climb another day should the altitude be too much this time. 

There is an assortment of ways climbers’ deal with the lack of oxygen and the risks associated with it.  Some choose to deal with high altitude by bringing along their own supplemental oxygen.  Others try and make it without the sometimes-cumbersome bottles and regulators.  There are also several different ways to speed up the tedious process of acclimatization that can even be carried out at sea level before even stepping on a plan to Everest.   

If one does get sick, descending and administering medication is de rigueur.  There is also a portable mechanical device that was created not long ago called the ‘Gamow Bag’ that was created to help treat AMS. 

In an ongoing series about Altitude, Oxygen,  and AMS we will explore some of the technology used to prevent and also treat AMS - Part II on Monday

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