What is mountain altitude sickness?
In recent years, the popularity of mountain tourism has increased significantly. People who go to the mountains are not always aware of the dangers that may await them during an unforgettable adventure. Tourists go to conquer the peaks without undergoing appropriate training and without the necessary experience. However, being at an altitude of 2500 meters can provoke the development of altitude sickness, accompanied by edema of the brain and lungs, as well as other pathological processes that can cause death.
Acute mountain sickness is a pathological condition provoked by a decrease in partial oxygen in the inhaled air, as well as fatigue, low air temperature and dehydration of the body. Almost the only (and most effective) first aid method in this case is a gradual decrease in height. If symptoms of mountain sickness appear, further ascent, especially a sharp one, is impossible: this can cause death!
1.General information
Caisson, or decompression sickness, is the notorious “caisson” that cost the health (and sometimes the lives) of many, many divers, scuba divers, submariners, high-altitude pilots and representatives of other professions associated with changes in environmental pressure and inhaled air.
The essence of this dangerous condition is the intense release of gas with the formation of many bubbles in the blood vessels and tissues. When such bubbles merge or group together, an embolism (blockage) may occur; in addition, increased mechanical pressure from the “gas clusters” often leads to damage to conductive nerves, muscle fibers and, in general, internal organs (the ligamentous-articular apparatus and the central nervous system are primarily affected).
The incidence of decompression sickness is currently 2-4 cases for every 10,000 dives to depth, rapid ascents to altitude, stays in caisson chambers, etc.
A must read! Help with treatment and hospitalization!
At what altitude does altitude sickness develop?
Mountain sickness develops when a person who has not gone through the acclimatization process rises above 2500 meters. Cases have been described in which symptoms appeared when climbing just 2000 meters.
Mountain sickness – at what altitude does it develop?
Adaptation disorders are recorded in 15-20% of climbers crossing an altitude of 4000 meters. When climbing to 6500 meters, complete acclimatization becomes impossible, which is why even experienced, trained climbers almost always experience symptoms of altitude sickness.
A person can stay at an altitude of more than 8000 meters for no more than three days; failure to descend inevitably causes death. Of course, the presence of an oxygen apparatus, a portable hyperbaric chamber and drugs that improve acclimatization makes it possible to survive at high altitudes for a longer period.
What kind of nutrition is needed at altitude?
In the prevention of mountain sickness, a complete and balanced diet is of great importance: varied and satisfying, containing sufficient amounts of proteins, carbohydrates, fats, mineral salts and vitamins. It is recommended to eat hot food rather than dry food. During the entire ascent, there must be hot sweet tea. Alcoholic drinks should be completely excluded from the diet. The statement that alcohol speeds up blood flow and instills vigor is wrong. After drinking alcoholic beverages, temporary excitement occurs, which after some time is replaced by a loss of strength and loss of the ability to pay attention, which is very harmful in high altitude conditions.
At altitudes exceeding 5000 m, the amount of fluid consumed should be at least 4-5 liters per day. This helps eliminate toxins and avoids dehydration. You should also increase the calorie content of food to 5000 kcal per day. If possible, dishes should be “spicy” to increase the secretion of digestive juices. In the process of adaptation to high altitudes, the oxidation of fatty acids becomes more difficult. Because of this, ketones accumulate in the body - under-oxidized products of fat metabolism, which can cause symptoms of “altitude sickness” such as nausea and vomiting.
It is justified to include in the diet a 10% increase in the amount of carbohydrates in the form of sucrose and glucose, since they suppress the formation of ketones and thereby prevent the appearance of unpleasant symptoms of hypoxia. In the process of adaptation to altitude sickness, instant and easily digestible milk proteins are recommended, as well as protein products specially created for this purpose (protein chocolate, protein cookies), freeze-dried meat and fish products. To combat “altitude sickness,” Nepalese advise drinking yogurt, which partially restores the acid-base balance in tissues and improves well-being.
Causes of mountain sickness
Why do some tourists develop altitude sickness while others do not? This depends on a number of factors: previous training, availability of rest, speed of climb and even hereditary factors.
Causes of altitude sickness
The main link in the pathogenesis of mountain sickness is a lack of oxygen, that is, hypoxia, which affects all tissues of the body. Temperature changes, hypothermia, fatigue, lack of opportunity for proper rest, poor nutrition, the presence of diseases of the respiratory system, for example, bronchitis, chronic obstructive pulmonary disease, previous COVID-19, etc. increase the risk of developing a pathological condition.
The most dangerous complications of mountain sickness are cerebral edema and pulmonary edema. Both conditions can be fatal and require immediate first aid and altitude reduction.
Mountain sickness: symptoms and degrees
There are three degrees of mountain sickness:
- Mild degree
A person complains of headache, nausea or vomiting, insomnia, dizziness. Symptoms are mild. To provide assistance, it is enough to stop climbing for a while and give the person time to acclimatize. After 3-4 days, the symptoms disappear on their own and do not require additional treatment;
- Moderate degree
Euphoria is added to the symptoms listed above. The person is in high spirits, he talks a lot, the pace of speech is accelerated. The attitude towards the environment changes: often a person begins to underestimate the dangers, which is why he requires constant monitoring. After some time, euphoria is replaced by apathy and loss of mood, severe weakness, dizziness, indigestion, and severe thirst;
- Severe degree
The main complaint continues to be headache, which is much more pronounced than with mild mountain sickness. Unsatisfactory health, dizziness occurs with any sudden movement. A person gets tired quickly and finds it difficult to do physical work. Frequent, shallow breathing. A common symptom is bleeding from the nose, esophagus, and possibly hemoptysis. Many people complain of severe dry throat, which makes them constantly thirsty.
High altitude cerebral edema
Cerebral edema is an excessive accumulation of fluid in the brain tissue, leading to increased intracranial pressure. Brain edema manifests itself as a disturbance in the patient's condition, headache, and disturbances of consciousness (up to coma). In the absence of timely assistance, cerebral edema leads to death.
High-altitude cerebral edema most often develops at night, which is associated with the horizontal position of the human body and increased venous return to the upper half of the body. An additional contribution is made by the fact that at night a person breathes less often and less deeply, which increases hypoxia.
High-altitude cerebral edema is an indication for immediate oxygen therapy and the use of medications if a physician is nearby. At the same time, it is necessary to begin resetting the altitude. Moreover, descent is required in all cases of suspected cerebral edema, as well as if the symptoms of mountain sickness do not stop. Further ascent is impossible.
If you suspect the development of cerebral edema, the victim should under no circumstances remain in a horizontal position for a long time! It is important to remember that even if the symptoms of incipient cerebral edema are recorded at night, descent must begin immediately, since by morning the victim’s condition almost always worsens!
What are the basic principles of acclimatization to altitude?
Basic principles of acclimatization:
- within the limits of reaching an altitude of 3000 m, increase the altitude of the overnight stay by 500-600 m every day.
- When climbing more than 3000 m, take a day every 1000 m.
- Do not travel by transport immediately to an altitude of more than 3000 m.
- remember that the rate of acclimatization varies significantly among different people;
- “climb high, sleep low”;
- in case of delivery by transport to a high altitude, do acclimatization for 24 hours;
- If the symptoms of altitude sickness intensify, the ascent should be stopped and the descent should begin.
The problems associated with acclimatization do not end after conquering the heights and descending into the valley. At this moment, the processes of adaptation to low altitudes begin to take effect in climbers. High partial pressure of oxygen impedes tissue repair processes. Alcohol, which climbers drink to celebrate their victory, can cause enormous harm at this moment. Alcohol in large doses sharply inhibits the function of brain neurons and tissue respiration enzymes. History remembers when experienced climbers died already in Kathmandu with an abundance of oxygen and normal climatic conditions. That is why descent from high altitude should also be done gradually.
To make it easier to stay at extreme altitudes, climbers use additional oxygen, which they carry with them in cylinders. This practice makes it much easier for them to stay in hypoxic conditions, but on the other hand, it is dangerous. At a certain point, oxygen can turn from a friend into an enemy and cause some, including fatal, complications. Due to the very low temperature at the outlet of the reducer, it can cause bronchospasm and pulmonary edema. It can cause dysregulation in the brain’s perception of the situation and poor decision-making. Doctors explain this by human adaptation to inhaling air as an oxygen-nitrogen mixture, and not to aspiration of pure oxygen. In addition, if the oxygen suddenly runs out, the climber risks instantly finding himself in a vacuum (like a depressurized airplane) with all the ensuing consequences of oxygen starvation on the brain, lungs, heart, and eyes. The same climber who climbs to the top without oxygen and can adapt to the altitude does not expose himself to such risks.
Every year, up to ten people die on the route to Everest Base Camp because they did not heed the advice and continued to move forward, despite their deteriorating health. Don’t repeat their mistakes, follow the rules of acclimatization, and only after your condition improves, feel free to move on!
Signs of high altitude pulmonary edema
The first signs of pulmonary edema are:
- Weakness, headache, rapid breathing.
- Later, pallor, blue lips and nails, restlessness, and wheezing are heard during breathing.
- A pinkish foam may be released from the mouth, which is foamed plasma containing red blood cells.
- If there is no treatment, the terminal phase of pulmonary edema occurs. The pressure drops, breathing becomes shallow and irregular.
The cause of death due to pulmonary edema is asphyxia.
Helps prevent the development of altitude sickness
- Gradual altitude gain and acclimatization.
Before making the climb, you should spend 6-7 days at medium altitudes (2200-3000 meters). This helps reduce the risk of developing altitude sickness and significantly improves oxygenation. The sharper the rise, the higher the risk of altitude sickness. On the contrary, a gradual rise, during which the body manages to adapt to changing conditions, is the main preventative measure for this pathological condition;
- Taking medications.
It has been proven that medications prescribed by a doctor help prevent mountain sickness, but we will not list them, as this is absolutely illegal. All drugs have a number of contraindications and side effects. In addition, in situations of low risk of developing mountain sickness, there is no need for prophylactic medication. That is, in most situations, you can count on avoiding altitude sickness by gradually increasing the altitude and providing climbers with adequate rest;
- Gradual increase in altitude.
At altitudes exceeding 3000 meters, the altitude of overnight stays cannot be exceeded by more than 500 meters per day. In this case, every 3-4 days it is necessary to arrange a rest day. If terrain or other factors prevent you from following this schedule, it is recommended to take a rest day before or immediately after climbing.
Altitude sickness while hiking and climbing - how to prevent it?
In order to weaken the effect of hypoxia, several effective methods have been developed, among which preparation for climbing, acclimatization, and proper nutrition deserve special attention.
Do you need to prepare for the climb?
To avoid mountain sickness while hiking and climbing, careful preparation is needed. During the two to three weeks preceding the ascent, training should begin. Adaptation to altitude by conquering low altitudes, spending a short time at these altitudes and quickly descending, as well as repeated alternation of ascents and descents, showed good effectiveness. Long-term acclimatization training accustoms human organs and tissues to work in conditions of oxygen deficiency.
Why is acclimatization needed?
Mountain sickness during mountain hiking and climbing, affecting the climber’s brain, deprives him of the ability to think critically about himself. When mild hypoxic euphoria sets in, everything seems accessible to a person. Tourists often try to organize competitions in rapid ascent. Such actions are extremely dangerous because they instantly disrupt adaptive mechanisms. As a result of rapid ascent, there is a high probability of hypoxic depression of consciousness, depression, and cardiovascular failure. On the contrary, proper acclimatization has a positive effect on the body’s adaptation to oxygen deficiency. With properly planned adaptation to mountain hiking, the body rearranges the order of redox processes and changes the composition of the blood, which allows it to better absorb oxygen and spend energy more economically.
What is the best method for adapting to altitude?
It is very important not to take a quick start in the first stages of trekking in the mountains. A good result was shown by the “run ahead” tactic, when the group stops for the night at an altitude that is lower than the highest point reached during the day. In Western Europe this method is called the "saw tooth" method. Despite the fact that “stepped” acclimatization requires a long period of time, it is the most effective and reliable method that makes it easier for the body to adapt to being at altitude. If a climber quickly rises from sea level to the top of Everest, he will die. However, there are already known cases when people conquered the highest peak without additional oxygen, spending a sufficient amount of time on the ascent - about 90 days.
The essence of the “saw teeth” method is to perform cycles: every day, rise and rest as high as possible, and then descend and spend the night as low as possible. For example, having gained 1000 m in a day, you should spend the night 400 m lower. With each subsequent ascent, the group reaches greater heights and reliably consolidates the experience of the previous day. It is very important to get a good rest at night. At this time, at altitude, a person is most vulnerable: he loses mobilization from the nervous system and tone, which is maintained during wakefulness by volitional efforts. At the same time, control of his condition by other participants in the ascent ceases. It is at night that deaths occur among those whose bodies are exposed to hypoxia. At the same time, a properly organized overnight stay at altitude makes it possible to adapt to this altitude to the greatest extent.
When choosing your actions, you should be guided by your heart rate - this is a pretty good indicator. The evening pulse of a tourist can be high and, in mild forms of mountain sickness, exceed 100 beats per minute. However, the morning contraction rate should drop to 80-90 beats per minute. If a person claims that his morning heart rate exceeds 105 beats per minute, then the group leader must escort him down, since he has not mastered the altitude during the night. Further ascent at such a morning pulse often leads to severe mountain sickness. At the same time, the group is delayed due to the fact that it has to lower the victim from an even greater height.
During the day's marches the group must move at the same pace. So that breathing is calm, uniform and does not get confused. Nepalese guides recommend moving in small steps at the speed of a yak - slowly. You can't do fast runs in the mountains, it's dangerous! At the same time, there is no need to be lazy during acclimatization. Continuous movement and moderate physical activity maintains blood circulation and makes it easier to cope with altitude sickness.
The altitude at which acclimatization starts is of great importance. If the group initially walks quickly and only at around 4000 m begins to move according to the rules of acclimatization, this can lead to wear and tear on the body and poor adaptation to high altitudes. It is not recommended to skip the acclimatization stage at an altitude of 3200-3500 m.
When trekking in the mountains, medical self-control and control over your condition is very important. Participants must periodically measure their pulse, blood pressure, and blood oxygen levels using a pulse oximeter.
First aid for mountain sickness
The main “cure” for altitude sickness is lowering altitude. The altitude is reduced until the symptoms of altitude sickness completely disappear. As a rule, the condition improves after dropping the height from 300 to 1000 meters, although this figure can vary greatly from person to person: for some, 200 meters may be enough, for others, it will be necessary to descend one and a half kilometers or more.
It is very important that descent should never be done alone, especially if there are signs of high-altitude cerebral edema.
Oxygen therapy greatly alleviates the patient's condition. However, oxygen is usually a backup remedy that is used in situations where, for one reason or another, altitude loss is impossible.
4.Treatment
Great importance is attached to the time factor: even with the apparent mildness of the symptoms, a patient with signs of decompression sickness should be taken to a medical facility as soon as possible.
The first-line treatment is usually hyperbaric oxygen therapy. General restorative, analgesic, anti-inflammatory, neuroprotective and other drugs are used symptomatically. Up to 80% of cases can be stopped without any special consequences.
However, due to the high risk of severe complications (both in the immediate and long-term period of decompression sickness), detailed methods of prevention have been developed - in the form of instructions for stepwise descent and ascent, monitoring the condition, monitoring over time, etc. These requirements must be followed strictly .
