Altitude sickness, known as Acute Mountain Sickness (AMS), hypobaropathy, or soroche, results from exposure to low air pressure, particularly the reduced partial pressure of oxygen encountered at high elevations. AMS tends to arise when individuals exert themselves at high altitudes, especially without adequate acclimatization. It is commonly observed above 2400 meters, and Kilimanjaro’s summit stands at nearly 6000 meters above sea level. At such heights, the air pressure, and consequently, oxygen levels, are less than half of those at sea level, often likened to ‘working with only one lung.’ AMS poses a serious threat, as it can be incapacitating, and seeking medical treatment in remote high-altitude locations can be challenging.
AMS susceptibility varies among individuals, making it challenging to predict. Typically, physically fit individuals are less susceptible than their less fit counterparts because their cardiovascular systems can endure lower pressures with less strain. Nevertheless, vulnerability exists for anyone above 3500 meters, regardless of fitness level, if they haven’t acclimated to lower atmospheric pressures. While the most effective way to gauge high-altitude reactions is firsthand experience, for many, this option is impractical. An alternative involves consulting a specialized altitude training company equipped with devices simulating altitude effects. In the UK the leading specialist is The Altitude Centre.
Preventing AMS
1. Employ the “walk high, sleep low” strategy. Gradually ascending to higher altitudes during the day and descending to sleep at lower elevations allows for a gradual adaptation to lower pressures, promoting overnight recovery
2. Embrace a slow and steady pace. Maintain a respiration rate conducive to a regular conversation. If you find yourself panting or breathing heavily, it’s crucial to slow down. Straining your heart and lungs significantly raises the risk of illness.
3. Hydrate generously. Consuming more water than you might instinctively think is necessary greatly aids in acclimatization. Aim for a minimum of three liters daily. As dehydration shares symptoms with altitude sickness, maintaining proper hydration improves the likelihood of permission to continue the climb.
4. Consider Diamox. Based on research consensus, Diamox is deemed helpful in preventing AMS, and it is part of our approach when ascending Kilimanjaro. We encourage you to independently research Diamox and its effects. Given that it is a prescription drug, consulting with your doctor before use is imperative.
Effects of exposure to low atmospheric pressure
1. Low oxygen saturation
At high altitudes and low pressures, each breath takes in less oxygen, and transfers less to the blood. Blood with low levels of oxygen is said to be poorly saturated. Having slightly low oxygen saturation can lead to fatigue and feeling breathless. Severe low oxygen saturation can cause impaired mental functions, reduce your decision making ability, and have other dangerous effects. All our guides have pulse-oxymeters to check your oxygen saturation daily.
2. Cerebral oedema
Severely reduced air pressure can cause fluid to collect in the sinuses and air cavities in the skull. Initially it presents as a mild headache, but can eventually cause disorientation, coma and even death. Cerebral oedema can present very suddenly, and is an extremely serious medical issue.
3.Pulmonary oedema
This is caused by reduced air pressure in the lungs. Fluid sometimes begins to seep from the lung tissues into the air spaces of the lungs, making breathing even more difficult. This often presents like pneumonia, and is most likely to occur during sleep.
How to recognise AMS
AMS does not present as a slow, gradual worsening of lesser altitude-related symptoms like breathlessness or headache. It is in fact generally a rapid, dramatic onset of symptoms that can render a person unable to walk or take care of themselves at all.
Our guides are trained to recognise AMS and apply the appropriate first aid. They will monitor your blood oxygen saturation and evaluate your overall acclimatisation, but it is vital that you monitor and report your condition accurately, for everyone’s safety.
Our client descent protocol
If our guides believe you may be in poor health or that allowing you to continue the climb may be dangerous, they will require you to begin your descent immediately. If that decision is made, it will be according to this protocol:
If it is below 80%, then you will be required to submit to another test every half hour, for the next two hours. If your saturation does not rise to at least 75%, you will be required to descend immediately. If your saturation is at least 75%, you will be allowed to continue subject to close monitoring. If your condition worsens you must notify your guide immediately, and begin the descent.
If your score is between 6 and 8 then the guide will consider whether you can continue based on your score, oxygen saturation levels, pulse rate and overall well-being. If you are allowed to continue, you will be monitored closely for the duration of the ascent. If your condition worsens you must notify your guide immediately, and begin the descent. If your Lake Louise Score is higher than 8, you must descend immediately.
