We all enjoy the tremendous view from a high summit, but there are risks in going to high altitude, it is important to understand these risks. The following is a small contribution from Destination Africa Tours to all Kili-hikers.

WHAT IS HIGH ALTITUDE?

Altitude is defined on the following scale: high; 2 438m - 3 658m, very high; 3 658m - 5 487m, and extremely high; 5 500m+. Since few people have been to such high 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 are more susceptible than others. The occurrence of AMS is dependent upon the elevation, the rate of ascent and individual susceptibility. Many people will experience mild AMS during the acclimatisation process.

WHAT CAUSES ALTITUDE ILLNESSES?

The concentration of oxygen at sea level is about 21% and the barometric pressure averages 760mmhg. As altitude increase, the concentration remains the same but the number of oxygen molecules per breath is reduced. At 3 658m the barometric pressure is only 438mmhg, so there are 40% fewer oxygen molecules per breath. In order to properly oxygenate the body, your breathing rate (even while resting) has to increase. Since the amount of oxygen required for activity is the same, the body must adjust to having less oxygen. In addition, 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.

ACCLIMATISATION

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 acclimatisation. For example if you hike to 3 048m your body acclimatise to 3 048m. If you climb to 3 658m, your body has to acclimatise once again.

A number of changes take place in the body to allow it to operate with decreased oxygen:
· Depth of respiration increases
· The body produces more red blood cells to carry oxygen
· Release of oxygen from haemoglobin to the body tissues
· Increased heart rates

SYMPTOMS OF ALTITUDE ILLNESS (AMS)

The symptoms of AMS tend to be worse at night when respiratory drive is decreased. Mild AMS does not interfere with normal activity and symptoms generally subside within 2-4 days as the body acclimatises. 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 illnesses immediately to others on your trip.

Signs and symptoms of Acute Mountain Sickness:
· Headache
· Malaise
· Loss of appetite, nausea and vomiting
· Peripheral oedema
· Disturbed sleep
· Shortness of breath

HEADACHE
Increased cerebral blood flow helps the brain maintain its oxygen supply, but the expanded volume causes pain as the system adapts.

MALAISE
Uneasy feeling, drowsiness, lassitude occurs because of decreased oxygen in the blood.

LOSS OF APPETITE, NAUSEA AND VOMITING
When blood is shunted to the vital organs (heart, lungs, brain), perfusion of the gastrointestinal tract decreases, compromising its function. Nausea and vomiting are the result.

PERIPHERAL OEDEMA
Persons with acute mountain sickness tend to retain fluid, resulting in oedema, especially of the face and hands.

DISTURBED SLEEP
During sleep, a person's rate and depth of respiration may gradually increase until it reaches a climax. Breathing then ceases entirely for 5 to 50 seconds. This phenomenon is called cheyne-stokes respiration. Cheyne-stokes breathing further decrease the level of oxygen in the blood.

CYANOSIS
A bluish appearance in the fingernail beds, mucous membranes and around the mouth occurs as a result of decreased oxygen saturation of the blood.

GUIDELINES FOR PROPER ACCLIMATISATION:
· Do not fly or drive to high altitude. Start below 3 048m and walk up.
· Do not over-exert yourself. · Climb high and sleep low (traverse).
· If symptoms of moderate altitude illness shows, do not hike higher until symptoms decrease.
· Stay properly hydrated. Acclimatisation is accompanied by fluid loss, Drink at least 3-litres per day. Urine output should be copious and clear.
· Take it easy. Do not over-exert yourself, when you first get up to altitude rest frequently.
· Avoid tobacco, alcohol and other depressant drugs including, sleeping pills. Depressants further decrease the respiratory drive during sleep, resulting in a worsening of the symptoms.
· Eat a high carbohydrate diet (more than 70% of your calories from carbohydrates) while at altitude.
· The acclimatisation process is inhibited by dehydration, over exertion, alcohol and other depressant drugs.

PREVENTIVE MEDICATIONS

DIAMOX allows you to breathe faster so that you metabolise more oxygen, thereby minimising the symptoms caused by poor oxygenation. This is 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're of to altitude and continue for at least five days at higher altitude. The recommendation is 125mg twice a day. Possible side effects include tingling of the lips and fingertips, blurring of vision and alteration of taste. Side effects subside when the drug is stopped. Since Diamox is a sulphonamide drug, people who are allergic to sulpha drugs should not take Diamox. Diamox has also been known to cause severe allergic reactions to people with previous history of allergies. We recommend a trial course of the drug before going to a remote location where a severe allergic reaction could prove difficult to treat.

Decahedron (a steroid) is not recommended.

Simply contact our team or the TRAVEL SAFE CLINIC for additional assistance on health issues.


REMEMBER "POLE-POLE" AS THERE IS NO RUSH IN AFRICA!

* Please note that the above information is to be used as a guideline only and that you should check with qualified medical personnel when using any medication.