Altitude Illness - Self Report

One of the main issues with travelling to Cusco is that as its at a high altitude (~3400 metres) it can lead to altitude illness. The most common type of altitude illness is Acute Mountain Sickness (AMS) which occurs in 20-70% of people going to high altitude. The symptoms of AMS are a headache as well as one of the following symptoms: nausea, vomiting, lack of appetite, dizziness or lightheadedness, sleeplessness and fatigue. In our group we have been completing an AMS questionnaire on a daily basis to measure the degree to which people have been developing symptoms associated with AMS. I am one of the people that have experienced symptoms suggesting that I have a poorer tolerance to altitude.

AMS. SpO2. Heart Rate
Day 1 morning. 5. 85. 66
Day 1 evening.  8. - -
Day 2 morning. 3. 85. 69
Day 3 morning. 4. 85. 69
Day 4 morning. 0. 94. 63
Day 5 morning. 0. 95. 72
Day 6 morning. 1. 92. 74

On the first full day in Cusco, even though I had a good long sleep the night before as I hadn't slept much on the plane journeys and I was already showing signs of AMS. I had a moderate headache, which is the main symptom of AMS as well as moderate light headedness. I also had an oxygen saturation of 85%, which was low in comparison with the rest of the group. Throughout the day the headache and dizziness became severe and I put an AMS score in the comments section as I felt it had significantly changed from the morning. The headache was very strong and had similar characteristics to a migraine as I struggled to cope with bright lights, therefore I was instructed to take ibuprofen. This did dull the headache down and allowed me to get a good nights sleep. If this had not improved my symptoms or had i felt as bad in the morning I would have been given Acetazolamide.

The onset of the illness usually in the first three days of reaching high altitude and usually lasts the same period. This is certainly the case with me as my questionnaire scores were greater in the first three days of the trip. In this period I consistently had a headache of a mild or moderate intensity as well as other symptoms. My saturation also stayed low at 85% while my resting heart rate remained relatively consistent. I found that the feeling was very similar to a hangover.

Those at greater risk of AMS are those who make a rapid ascent, people who have had a recent cold and retain fluid at altitude or do not urinate excessively at arrival at high altitude. Due to travelling from Eastbourne at sea level to Cusco this would make it a rapid ascent therefore predisposing people to the illness. Also on the first day I drank 4.5 litres of water, a bottle of coke and a cup of tea but only had five urinations. This suggests that I was retaining my fluids as well as not urinating excessively at arrival. Although i would have had a higher than normal sweat rate due to the excessive heat. I also experienced high altitude oedema in my ankles and lower legs which occurs more frequently in those with AMS.

After the first three days, my oxygen saturation significantly improved as well as my results on the questionnaire. This fits in with the idea that the illness occurs in the first days, after this period the results and my general feelings suggest that I have become acclimatised to the low levels of oxygen so that the necessary amounts of oxygen can be transported to the cells.

We haven't had any members of our group suffer with severe AMS, High Altitude Pulmonary Edema or High Altitude Cerebral Edema. This would be unlikely normally, but more so as our group are specifically measuring responses, very weary of symptoms and have been treating any symptoms early and appropriately. As we have gone past the time when you are most likely to have altitude illness hopefully nobody else will suffer with any altitude illness. We are carrying on the questionnaire and physiological measures to identify any problems that may arise. The next danger point is the increase in altitude along the Inca Trail which goes up to ~4200 metres but hopefully everyone will get through unscathed.

James

Para-monte: Altitude illness awareness charity

Some of you reading this may well have heard the tragic story of the Eastbourne resident Adam Savory dying of altitude illness in Cusco Peru in September 2012. This was recently reported in the Eastbourne Herald on 25th January 2013. News Article

Within the report you will find the family and friends are working hard to develop a charity, Para-monte, to raise awareness of altitude illnesses and the methods to recognise symptoms and what to do if they occur. This charity will offer such an important information source for people travelling to altitude.



All individuals doing the Peru project offer their deepest sympathies with the family and friends of Adam and will help in whatever way we can to spread the word of Para-monte and altitude illness awareness, to reduce the chance of others in the future suffering the same.

We also hope that the research being undertaken here will help towards the understanding of altitude illnesses and the sea level prediction of if.

High altitude health advice

High Altitude Health Advice

Typically mountaineers ascend from low to higher altitudes and are thus exposed to continuously increasing hypoxia. As the altitude increases, the barometric pressure within the surrounding environment falls. This drop in barometric pressure, and thus drop in the density of the air means that there are fewer oxygen molecules in a given volume of air than there are at sea level. Therefore with each breath, less oxygen is able to be taken in and utilised by the body. This subsequent reduction in oxygen delivery coupled with various other confounding factors can therefore induce health issues for an individual at altitude.

This page will identify the health issues that are likely to arise on a trip to high altitude (above 2,500m) and provide advice as to how these conditions may be prevented and/or treated in order to maximise both the safety and the enjoyment from any high altitude sojourn.

These pages offer advice and guidelines that have been based on previous literature. These pages however should not be taken as the only options and any individual travelling to altitude should seek medical advice from an expert before doing so.

Acute effects of hypoxia; the initial effects of altitude exposure

A number of physiological responses occur when an individual is first exposed to altitude. The awareness of these responses is important for the mountaineer or the recreational climber;

·         An increase in ventilation. i.e. the rate and depth of breathing
·         An increase in both the heart rate (HR) and the cardiac output of an individual
·         Increased diuresis
·         Increased blood lactate
·         Greater red blood cell (RBC) production (Approximately after seven days)
·         Increased perception of effort

Acclimatisation

The acute responses to hypoxia outlined above, indicate the fact that the human body is an adaptive organism that has the ability to adjust to the changing environment around it and that the acclimatisation of the body to altitude, albeit up to a certain point, is possible. Acclimatisation is a term used to describe the slow adaptation of the body to cope with the lower levels of oxygen at altitude and should figure in the planning of all individuals preparing to ascend to high altitude. If adequate time is allowed during a climb to high altitude, the majority of healthy individuals will be able to function unhindered. This, in turn will increase the chances of summiting.

When travelling to high altitude sufficient acclimatisation is also imperative in order to avoid altitude illnesses. The speed of the ascent and the susceptibility of an individual are the two main determining factors culminating in the risk of developing an altitude illness. When going too high too fast, the body is unable to adapt sufficiently and life-threatening illnesses may be the consequence. Susceptibility to such illness differs from person to person, however and an altitude that may evoke symptoms in certain climbers may provoke no such effect in others. Therefore In a group of climbers the acclimatisation process should always be tailored to ensure that the health of the individual who is slowest to acclimatise is maintained.

So what is recommended?

·         Do not rush the acclimatisation phase (It is now possible to start the acclimatisation process prior to departure)

·         Do not sleep at an altitude exceeding 300m higher than the previous night

·         If possible schedule a rest day every 2-3 days

·         Ensure, if climbing in a group, the process is tailored to the individual who is slowest to acclimatise

·         Be aware of the time course of AMS (below)

Acclimatisation to hypoxia is, as already stated, possible up to a certain threshold. It is estimated that the upper limit for the permanent acclimatisation of an individual is approximately 5,000m. Above which the process of permanent acclimatisation becomes impossible as the body starts to deteriorate. Short term acclimatisation, however is possible amongst healthy individuals to an altitude of approximately 6,500m. Above this point (extreme altitude) the body will deteriorate linearly with increasing altitude and supplementary oxygen will usually always have to be administered.

Acute Mountain Sickness (AMS)

The most common illness associated with travel to altitude is termed acute mountain sickness (AMS). AMS develops in mountaineers ascending to high altitudes who are un-acclimatised. The condition usually develops within 6-12 hours of reaching a critical altitude and peaks at approximately 24 hours. Although some incidences of AMS have been reported at as low as 1000m the condition is usually experienced at an altitude of approximately 3,000m and above.

 The incidence of AMS increases with altitude, and hypoxia is the main causative factor for the onset of the illness. When mountaineers ascend rapidly to 2,500 m, about 10% will suffer from AMS, and when ascending to 4,500 m, the AMS incidence will exceed 60%. Therefore an individual climbing Mount Kilimanjaro for example, which stands at a height of 5,985m, should expect to develop at least some of the symptoms associated with AMS and therefore take precautions for both the prevention and treatment of such symptoms.

 AMS is characterised by;

·         Frontal lobe headache

·         Nausea

·         Fatigue

·         Vomiting

·         Tiredness/ difficulty sleeping

·         Lack of appetite

 In more severe cases further symptoms include;

·         Ataxia (decreased co-ordination)

·         Decreased mental status i.e. confusion, aggression

How to treat AMS

During slow ascents with multiple overnight stays at altitude, an individual acclimatizes, and AMS can be avoided, once again highlighting the importance of a well planned acclimatisation schedule and illustrating how prevention is better than treatment. However, often such symptoms, such as a headache, are inevitable at altitude with approximately 96% of all people at high altitude suffering from the symptom. Therefore it is of importance to know what can be done to combat such symptoms at altitude.

It is also of importance to be aware of the time frame of such altitude conditions in order to determine whether an individual has truly passed the vulnerable stage of the illness and can therefore continue with their ascent. This, however in some cases is difficult as the development of symptoms can continue to worsen from anywhere between 12 hours and 3 days.  
  

The occurrence of AMS does not necessarily spell the end of a climb; it does however mean that certain measures should be taken in order to prevent the development of AMS in to a more serious condition. Such measures include;

·         Administration of supplemental oxygen

·         Sufficient fluid replacement

·         The cessation of any further ascent for at least 1 day (or until symptoms are reduced)

·         The use of acetazolamide (Diamox)

·         The use of Paracetamol/Ibuprofen in order to combat headaches

·         If symptoms persist it is imperative individuals descend

General advice whilst at high altitude

 ·         Keep an eye on fellow climbers

·         Be honest regarding how you are feeling, do not lie about,  or undersell any symptoms you may have

·         Be prepared before you leave

·         Make sure you know how to prevent, identify and treat the illnesses that may arise

·         Remember that slow ascent is the most important measure to prevent the onset of altitude illness

·         If you have any existing health conditions prior to departure i.e. diabetes, asthma etc, ensure you see a doctor or specialist to find out the risks your condition may pose to high altitude travel and ensure you  have taken all precautions necessary

The use of the drug acetazolamide has been mentioned a number of times. This drug, with the trade name of Diamox, is used as prevention against the effects of AMS. The drug works by speeding up the acclimatisation process and can also aid the sleep condition of periodic breathing. Although the drug works to reduce the effects of AMS it does not mask the symptoms and mountaineers should be aware that individuals can still suffer from AMS as well as the more serious conditions of HAPE and HACE whilst taking the drug. It is also important to be aware that some people may be allergic to the drug which may cause the tingling of the extremities; however this will cease when the taking of the drug has stopped.

The use of a pressure bag, or a Gamow bag as it is also known, has also been recommended. Although these bags can save lives it is also important to be aware of the accompanying problems that come with such equipment. Such problems include difficulty communicating with an individual inside the bag and the subsequent difficulty in monitoring their situation. Furthermore if dealing with an individual who has lost consciousness a person will need to be inside in order to closely monitor the condition of the ill individual. Moreover such bags can damage the eardrums and in many cases recovery is often short lived. Nevertheless, as already stated such a piece of equipment can save lives at high altitude and it is essential for an individual planning on travelling to such an environment to be aware of such equipment.

Further possible health problems at altitude

·         Blocked nose and sore throat

·         Sun burn

·         Dehydration

·         Heat stroke

·         Hypothermia/hyperthermia

·         Exhaustion

·         Diarrhoea

·         Constipation

 A number of health issues, big and small, are possible to occur when travelling to high altitude and as already stated individuals should be aware of what the risks are. This page has outlined the main and most serious illnesses and provided advice as to how these illnesses can be prevented and treated. Prevention is the best treatment and if properly prepared there is no reason why these conditions should spoil your climbing/ mountaineering experience.  

 Good Luck!

 References;

Burtscher, M. (2007). Arterial oxygen saturation during ascending to altitude under various conditions: Lessons from the field. Journal of Science and Medicine in Sport. 6, 535-537.

Burtscher, M., Brandstatter, E., Gatterer, H. (2007). Preacclimatisation in simulated altitudes. Sleep Breath. 12 (2). 109-114.

Burtscher, M., Szubski, C., Faulhaber, M. (2007). Prediction of the susceptibility to AMS at simulated altitude. Sleep Breath. 12 (2). 103-108.

Maggiorini, M., Melot, C., Pierre, S. Et al. (2001). High altitude pulmonary edema is initially caused by an increase in capillary pressure. Circulation. 103 (16). 2078-83.

Roach, R.C., Hackett, P.H. (2001). Frontiers of hypoxia research: acute mountain sickness.The Journal of Experimental Biology. 18. 3161-70.

Strote, J., Prutkin, J. (2006). High-altitude pulmonary edema presenting 18 hours after descent. Wilderness and Environmental Medicine. 17 (2). 137-9.

Tannheimer, M.A.J., Albertini, A., et al. (2009). Testing individual risk of acute mountain sickness at greater altitudes. Military Medicine. 174 (4). 363-9.