Mal d'altitude : voyager ou vivre à haute altitude peut être dangereux.
I've taken an article by a college student and edited it to more conform to my way of thinking. I will not embarrass the student by revealing their name as I have refuted many of their drug based theories, opinions and suppositions. This article is my opinion based on my experience. Take it as such and draw your own conclusions.
Traveling or living at high altitude can be hazardous.
Occasionally we have people take our breathing classes when planning a trip to high altitude or scuba diving. We also have the students living at high altitude that are practicing our techniques and exercises for day to day breathing and energy maintenance.
Some of you out there may travel from sea level to 5,000 feet and still feel ok. Add a few more thousand feet and suddenly one can feel less well then they did at sea level. It's essential that we understand the physiological effects of high altitude.
What is High Altitude?
Altitude is defined on the following scale: High (8,000 - 12,000 feet [2,438 - 3,658 meters]), Very High (12,000 - 18,000 feet [3,658 - 5,487 meters]), and Extremely High (18,000+ feet [5,500+ meters]). Since few people have been to such altitudes, it is hard to know who may be affected.
There are no specific factors such as age, sex, or physical condition that correlate with susceptibility to altitude sickness. Some people get it and some people don't, and some people are more susceptible than others.
If you haven't been to high altitude before, it's important to be cautious. If you have been at that altitude before with no problem, you can probably return to that altitude without problems as long as you are properly acclimatized. Just remember my 5,000 foot rule.
What Causes Altitude Illnesses?
The concentration of oxygen at sea level is about 21% and the barometric pressure averages 760 mmHg. As altitude increases, the concentration remains the same but the number of oxygen molecules per breath is reduced. At 12,000 feet (3,658 meters) the barometric pressure is only 483 mmHg, so there are roughly 40% fewer oxygen molecules per breath.
In order to properly oxygenate the body, your breathing rate (even while at rest) has to increase. This extra ventilation increases the oxygen content in the blood, but not to sea level concentrations. Since the amount of oxygen required for activity is the same, the body must adjust to having less oxygen.
In addition, for reasons not entirely understood, high altitude and lower air pressure causes fluid to leak from the capillaries which can cause fluid build-up in both the lungs and the brain. Continuing to higher altitudes without proper acclimatization can lead to potentially serious, even life-threatening illnesses.
The major cause of altitude illnesses is going too high too fast. Given time, your body can adapt to the decrease in oxygen molecules at a specific altitude. This process is known as acclimatization and generally takes 1-3 days at that altitude.
- The depth of respiration increases.
- Pressure in pulmonary arteries is increased, "forcing" blood into portions of the lung which are normally not used during sea level breathing.
- The body produces more red blood cells to carry oxygen,
- The body produces more of a particular enzyme that facilitates the release of oxygen from hemoglobin to the body tissues.
The traditional medical approach to prevention of altitude illnesses falls into two categories, proper acclimatization and preventive medications. Below are a few basic guidelines for proper acclimatization.
- If possible, don't fly or drive to high altitude. Start below 10,000 feet (3,048 meters) and walk up.
- If you do fly or drive, do not over-exert yourself or move higher for the first 24 hours.
- If you go above 10,000 feet (3,048 meters), only increase your altitude by 1,000 feet (305 meters) per day and for every 3,000 feet (915 meters) of elevation gained, take a rest day.
- "Climb High and sleep low." This is the maxim used by climbers. You can climb more than 1,000 feet (305 meters) in a day as long as you come back down and sleep at a lower altitude.
- If you begin to show symptoms of moderate altitude illness, don't go higher until symptoms decrease ("Don't go up until symptoms go down").
- If symptoms increase, go down, NOW!
- Keep in mind that different people will acclimatize at different rates. Make sure all of your party is properly acclimatized before going higher.
- Stay properly hydrated. Acclimatization is often accompanied by fluid loss, so you need to drink lots of fluids to remain properly hydrated (at least 3-4 quarts per day). Urine output should be copious and clear.
- Take it easy; don't over-exert yourself when you first get up to altitude. Light activity during the day is better than sleeping because respiration decreases during sleep, exacerbating the symptoms.
- Avoid tobacco and alcohol and other depressant drugs including, barbiturates, tranquilizers, and sleeping pills. These depressants further decrease the respiratory drive during sleep resulting in a worsening of the symptoms.
- Eat a high raw/living carbohydrate diet (more than 70% of your calories from simple carbohydrates) while at altitude.
- The acclimatization process is inhibited by dehydration, over-exertion, and alcohol and other depressant drugs.
- E3live may be a significant booster food to remain at and speed recovery from being at altitude as it adds more hemoglobin to capture oxygen molecules. Similar to eating red meat at altitude for the red blood cells.
- OxyLift also saturates the blood with extra oxygen
- Oxygen enhanced exercise and rest
- Diamox (Acetazolamide) allows you to breathe faster so that you metabolize more oxygen, thereby minimizing the symptoms caused by poor oxygenation. This can be especially helpful at night when respiratory drive is decreased. Since it takes a while for Diamox to have an effect, it is advisable to start taking it 24 hours before you go to altitude and continue for at least five days at higher altitude.
- The recommendation of the Himalayan Rescue Association Medical Clinic is 125 mg. twice a day (morning and night). They like it for rescue and so do I. The standard dose was 250 mg., but their research showed no difference for most people with the lower dose, although some individuals may need 250 mg.
- Possible side effects include tingling of the lips and finger tips, blurring of vision -coincidentally also hyperventilation (too little CO2) signals, and alteration of taste. These side effects may be reduced with the 125 mg. dose. Side effects subside when the drug is stopped. Contact your physician for a prescription.
- Since Diamox is a sulfonamide drug, people who are allergic to sulfa drugs should not take Diamox. Diamox has also been known to cause severe allergic reactions to people with no previous history of Diamox or sulfa allergies. Frank Hubbell of SOLO recommends a trial course of the drug before going to a remote location where a severe allergic reaction could prove difficult to treat. More about all this later in this article.
- Common side effects are nausea, vomiting, tingling feelings in the arms, legs, lips, mouth, or anus; appetite and weight loss; a metallic taste; increased frequency to urinate, diarrhea; not feeling well; occasional drowsiness; and weakness. See the Pill Book for more.
- Dexamethasone (a steroid) is a prescription drug that decreases brain and other swelling reversing the effects of AMS.
- Dosage is typically 4 mg twice a day for a few days starting with the ascent. This prevents most symptoms of altitude illness. It should be used with caution and only on the advice of a physician because of possible serious side effects. It may be combined with Diamox. No other medications have been proven valuable for preventing AMS.
- The Pill Book 11th edition states that long term use can lead to eye damage. Common side effects are water retention, heart failure, potassium loss, muscle weakness, loss of muscle mass, slowed healing of wounds, black and blue marks, increased sweating, allergic rash, itching, convulsions, dizziness, headache. Less common includes slowed growth in children. Get the Pill book for the other side effects.
AMS is common at high altitudes. At elevations over 10,000 feet (3,048 meters), 75% of people will have mild symptoms. The occurrence of AMS is dependent upon the elevation, the rate of ascent, and individual susceptibility. Many people will experience mild AMS during the acclimatization process.
Symptoms usually start 12-24 hours after arrival at altitude and begin to decrease in severity about the third day. The symptoms of Mild AMS are headache, dizziness, fatigue, shortness of breath, loss of appetite, nausea, disturbed sleep, and a general feeling of malaise.
Symptoms tend to be worse at night and when respiratory drive is decreased. Mild AMS does not interfere with normal activity and symptoms generally subside within 2-4 days as the body acclimatizes. As long as symptoms are mild, and only a nuisance, ascent can continue at a moderate rate.
When hiking, it is essential that you communicate any symptoms of illness immediately to others on your trip. AMS is considered to be a neurological problem caused by changes in the central nervous system. It is basically a mild form of High Altitude Cerebral Edema (see below).
Basic Treatment of AMS
The only cure is either acclimatization or descent. Our breathing development program will often greatly aid acclimatization.
Symptoms (But the cause will remain )of Mild AMS can be treated with pain medications for headache and Diamox. Both help to reduce the severity of the symptoms, but remember, reducing the symptoms is not curing the problem. As stated, one drug that allows you to breathe faster so that you might metabolize more oxygen, supposedly minimizing the symptoms caused by poor oxygenation.
But breathing faster puts stress on the nervous system and reduces the benefits of sleep and rest. It also may well decrease the carbon dioxide stores and cause LESS oxygen to be absorbed instead of more.
Drug proponents say this is especially helpful at night when respiratory drive is decreased. I've read that since it takes a while for Diamox to have an effect, it is advisable to start taking it 24 hours before you go to altitude and continue for at least five days at higher altitude.
The recommendation of the Himalayan Rescue Association Medical Clinic is 125 mg. twice a day (morning and night). (The standard dose was 250 mg., but their research showed no difference for most people with the lower dose, although some individuals may need 250 mg.) Possible side effects include tingling of the lips and fingertips, blurring of vision (hyperventilation/overbreathing signals), and alteration of taste.
These side effects may be reduced with 125 mg. dose. Side effects subside when the drug is stopped. Contact your physician for a prescription. Since Diamox is a sulfonamide drug, people who are allergic to sulfa drugs should not take Diamox.
Diamox has also been known to cause severe allergic reactions to people with no previous history of Diamox or sulfa allergies. It is recommended taking a trial course of the drug before going to a remote location where a severe allergic reaction could prove difficult to treat. I recommend not taking it in the first place unless it is a dire emergency and to develop your breathing instead.
Moderate AMS includes severe headache that is not relieved by medication, nausea and vomiting, increasing weakness and fatigue, shortness of breath, and decreased coordination (ataxia). Normal activity is difficult, although the person may still be able to walk on their own.
At this stage, only advanced medications or descent can reverse the problem. Descending even a few hundred feet (70-100 meters) may help and definite improvement will be seen in descents of 1,000-2,000 feet (305-610 meters). Twenty-four hours at the lower altitude will result in significant improvements.
The person should remain at lower altitude until symptoms have subsided (up to 3 days). At this point, the person has become acclimatized to that altitude and can begin ascending again. The best test for moderate AMS is to have the person "walk a straight line" heel to toe.
Just like a sobriety test, a person with ataxia will be unable to walk a straight line. This is a clear indication that immediate descent is required. It is important to get the person to descend before the ataxia reaches the point where they cannot walk on their own (which would necessitate a litter evacuation).
Severe AMS presents as an increase in the severity of the aforementioned symptoms, including shortness of breath at rest, inability to walk, decreasing mental status, and fluid buildup in the lungs. Severe AMS requires immediate descent to lower altitudes (2,000 - 4,000 feet [610-1,220 meters]).
There are two other severe forms of altitude illness, High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE). Both of these happen less frequently, especially to those who are properly acclimatized.
When they do occur, it is usually with people going too high too fast or going very high and staying there. The lack of oxygen results in leakage of fluid through the capillary walls into either the lungs or the brain.
High Altitude Pulmonary Edema (HAPE)
HAPE results from fluid buildup in the lungs. The fluid in the lungs prevents effective oxygen exchange. As the condition becomes more severe, the level of oxygen in the bloodstream decreases, and this can lead to cyanosis, impaired cerebral function, and death.
Symptoms include shortness of breath even at rest, "tightness in the chest," marked fatigue, a feeling of impending suffocation at night, weakness, and a persistent productive cough bringing up white, watery, or frothy fluid. Confusion, and irrational behavior are signs that insufficient oxygen is reaching the brain. One of the methods for testing yourself for HAPE is to check your recovery time after exertion.
If your heart and breathing rates normally slow down in X seconds after exercise, but at altitude your recovery time is much greater, it may mean fluid is building up in the lungs. In cases of HAPE, immediate descent is a necessary life-saving measure (2,000 - 4,000 feet [610-1,220 meters]). Anyone suffering from HAPE must be evacuated to a medical facility for proper follow-up treatment.
High Altitude Cerebral Edema (HACE)
HACE is the result of swelling of brain tissue from fluid leakage. Symptoms can include headache, loss of coordination (ataxia), weakness, and decreasing levels of consciousness including, disorientation, loss of memory, hallucinations, psychotic behavior, and coma.
It generally occurs after a week or more at high altitude. Severe instances can lead to death if not treated quickly. Immediate descent is a necessary life-saving measure (2,000 - 4,000 feet [610-1,220 meters]).
There are some medications that may be prescribed for treatment in the field, but these require that you have proper training in their use. Anyone suffering from HACE must be taken to a medical facility for proper follow-up treatment.
Other Medications for Altitude Illnesses
Gamow Bag (pronounced ga´ mä)
This clever invention has revolutionized field treatment of high altitude illnesses. The bag is basically a sealed chamber with a pump. The person is placed inside the bag and it is inflated. Pumping the bag full of air effectively increases the concentration of oxygen molecules and therefore simulates a descent to lower altitude.
In as little as 10 minutes the bag can create an "atmosphere" that corresponds to that at 3,000 - 5,000 feet (915 - 1,525 meters) lower. After a 1-2 hours in the bag, the person's body chemistry will have "reset" to the lower altitude.
This lasts for up to 12 hours outside of the bag which should be enough time to walk them down to a lower altitude and allow for further acclimatization. The bag and pump weigh about 14 pounds (6.3 kilos) and are now carried on most major high altitude expeditions. Bags can be rented for short term trips such as treks or expeditions.
Above 10,000 feet (3,000 meters) most people experience a periodic breathing during sleep known as Cheyne-Stokes Respirations. The pattern begins with a few shallow breaths and increases to deep sighing respirations then falls off rapidly.
Respirations may cease entirely for a few seconds and then the shallow breaths begin again. During the period when breathing stops the person often becomes restless and may wake with a sudden feeling of suffocation as with sleep apnea. This can disturb sleeping patterns, exhausting the climber.
Acetazolamide is helpful in relieving the periodic breathing. This type of breathing is not considered abnormal at high altitudes by many but I do consider it abnormal. However, if it occurs first during an illness (other than altitude illnesses) or after an injury (particularly a head injury) it may be a sign of a serious disorder.
Most people without a breathing challenge can go up to 5,000 with minimal effect. If you get fatigued at any altitude you will want to address your breathing. Our breathing development system should make it easier to attain a much higher altitude than before. You can also help oxygen transport with e3live and Oxylift.
The above overview gives me more insight how and why a client having seizures worked with our 176 video and was able to ascend 1,500 to 7,000 feet to the general store she had previously been unable to reach due to oxygen starvation and increased intensity of seizures.
By the way, there are several so-called "hyperbaric" products coming out on the market that are simply versions of the Gamow bag referred to above instead of Hyperbaric OXYGEN chambers which deliver up to 40 times more oxygen saturation than most "soft" chambers.
Though any valid means of significantly increasing oxygen when needed or wanted is mostly worthwhile, I believe many are using the term hyperbaric inappropriately to their own economic ends.
BEWARE of the tensions caused by restricting breathing volume. Our techniques in The Breathing Kit will offset those tensions.
The best way to get oxygen is the way God originally intended; optimal natural breathing.