International altitude division
The international altitude division is as follows:
1500—3500 meters is high altitude (High Altitude);
3500-5500 meters is very high altitude (Very High Altitude);
5500 meters above is extremely high altitude (Extreme High Altitude).
Usually most people have no problem reaching the height of 2400 meters. If the altitude exceeds 2400 meters, it is possible to suffer from altitude illness! The division is as follows: the main cause of illness is climbing too high and too fast; if given enough time, the body can still adapt to the air pressure at high altitude. Of course, there is a limit to this “adaptation”: after more than 5500 meters, no matter how much time it takes, you will not be able to adapt; (High Altitude Deterioration). The fact is: the places where people live for a long time on earth are below 5500 meters.
High Altitude Acclimatization( High Altitude Acclimatization )
Because the oxygen concentration at high altitude decreases, the body will undergo the following physiological changes in order to obtain enough oxygen:
·breathing accelerates and deepens
·blood pressure in the pulmonary arteries increases, forcing blood to flow through the alveoli, which are not normally used in the lower places
·made More red blood cells
· make more enzymes that make heme release oxygen (2,3-DPG for short)
· more capillaries in skeletal muscles
·decreased plasma volume
·increased the number and volume of glands
·increased the number of oxidative enzymes
altitude adaptation strategies
· Try not to go to high altitude by car or plane, it is best to start climbing below 3000 meters (I believe that friends who have been to Tibet or mountaineering should have a profound experience)
· By car or plane, don??t be overworked within 24 hours after arriving at a high place (for example, the altitude of Gongga Airport in Tibet is about 3500 meters, you should pay special attention at this time, don??t jump and shout excitedly when you get off the plane-mdash; —Otherwise, it won’t take long before you can’t even cry! Hehe)
· Above 3000 meters above sea level, the daily elevation of sleep
altitude should not exceed 300 meters; 2-3 days high (600-900 meters), you should stay one more night to rest at the same height
·[climb to a high place, go back to a low place to sleep], you can climb more than 300 meters in one day, But be sure to go back to sleep
·If symptoms of altitude sickness occur, do not continue to ascend until symptoms disappear
·If it worsens, descend immediately
·Add water, drink at least 4-5 liters of water every day, until the urine is clear or at least light yellow
·Most of the “mules” who have been to Tibet say that they are the first to go to Lhasa It is best to get a good night’s sleep to adapt to the high altitude; in fact, during the day, relaxing activities are better than sleep, because the breathing function will slow down during sleep, which will exacerbate the symptoms of altitude sickness
· Carbohydrate-based, at this time more than 70% of the calories should be derived from carbohydrates, such as rice, noodles, biscuits, etc.
·Avoid smoking, drinking and taking other drugs that depress the nervous system, such as sedatives, sleeping pills, babbitates, etc.
Acute altitude sickness< /strong>??Acute Mountain Sickness??
Over 3000 meters above sea level, 75% (oh! Why am I not the 25%?!) people will have mild acute mountain sickness (referred to as AMS) symptoms : Headache, Anorexia, Nausea, Vomiting, Fatigue, Weakness, Dizziness, Lightheadness and Difficult Sleeping . It is likely to be mistaken for a cold or acclimatization.
The appearance of symptoms depends mainly on the speed of ascent, height and individual physique.
The feeling of altitude sickness should not continue to rise. If you don??t deal with it properly or ignore altitude sickness and try to rise reluctantly, it is very likely to cause more serious or even fatal altitude sickness, such as: high altitude cerebral edema, high altitude pulmonary edema, etc. .
Acute Mountain Sickness (AMS) Coping Strategies
·stay in place and rest
Benefits: adapt to current altitude without wasting ascent progress
Disadvantages: May take 24-48 hours to get better, with the potential to worsen
·immediate descent
Benefits: rapid recovery (usually within a few hours) Recovery)
Disadvantage: waste of ascent progress and difficulty retreating at night or in bad weather
High Altitude Cerebral Edema< /p>
Alpine cerebral edema (HACE for short) is the most severe form of altitude sickness, usually occurring at altitudes above 4,300 meters: the brain thinks that it cannot get enough oxygen and is damaged, and then expands in the cranial cavity, causing the brain tissue to suffer damage. The hard cranium crushes, eventually leading to death. Symptoms are: ataxia and altered mental status. However, it should be noted that patients with alpine cerebral edema may have no symptoms of acute altitude sickness at all, and may not necessarily have headaches. This needs to be judged by observing whether the peers have the following abnormal behaviors: such as unsteady pace, frequent mistakes, etc.
·Ataxia: The coordination of limbs is affected by the inability of the brain to work properly. To test for dyskinesia, place one heel against the other toe, and “measure” the straight line on the ground (traffic police also use this method to check whether drinking and driving, huh); another method is to lie on the ground and use the edge of the heel The other calf slides, and under normal circumstances, the movement should be smooth. In severe cases, the patient may have difficulty with small movements such as tying shoelaces or even holding a water bottle. Alpine cerebral edema should be assumed if ataxia is present.
· Change in Mental Status: such as amnesia, hallucinations and even semi-consciousness and stupor. It can be tested by repeating a passage and doing some simple operations.
Remember (Warning)! ! !
Alpine cerebral edema (HACE) can be considered as [end stage] or [severe acute altitude sickness]. When you have just climbed to the heights and find: ataxia and/or mental status changes in people with AMS; or mental status changes and ataxia in patients with non-acute altitude sickness, you should immediately descend to the Safe height: 600-1200 meters.
High Mountain Cerebral Edema (HACE) Coping Strategy
Immediately descend to the lower place, the sooner the lower the better! Don’t delay, and don’t spend time waiting for help??unless the environment is too bad or your teammates are immobile??and take the opportunity to descend as soon as possible while the patient is still able to move. Remember that one second of delay reduces the patient’s chance of survival!
High Altitude Pulmonary Edema (High Altitude Pulmonary Edema )
High Altitude Pulmonary Edema (HAPE) is the accumulation of water in the alveoli that hinders gas exchange, resulting in like drowning. Usually, it is due to the rapid ascent without getting used to the high mountains, and the vigorous exercise immediately after reaching the high ground – friends who have watched “Vertical Limit” should remember that the three climbers in the film got HAPE. It is important to know that HAPE patients do not necessarily have AMS (acute mountain sickness) symptoms at the same time. When the situation worsens, the oxygen concentration in the blood drops severely and causes cyanosis (manifested as blue lips), which affects brain function and eventually leads to death.
Remember:
At least two of the following symptoms were found after just reaching the heights:
· dyspnea at rest, cough Cough , possibly ,production of frothy or pink sputum
·weakness or decreased exercise performance
·chest tightness or congestion
and at least two of the following:
·popping or wheezing in at least one lung Crackles or wheezing in at least one lung field
·central cyanosis, such as lips
·tachypnea
· Rapid heartbeat (tachycardia)
It can be judged as high mountain pulmonary edema, and the countermeasures:
Same as high mountain cerebral edema (HACE): immediately descend the mountain (600-1200 meters)
High Altitude Retinal Hemorrhage (High Altitude Retinal Hemorrhage)
Usually occurs at altitudes above 4,300 meters and occurs in about 30% of people at 5,300 meters. Usually this bleeding does not affect vision and is painless. However, in rare cases, when the hemorrhage is severe and affects the visual focus on the retina, the patient can not see a certain field of vision or cause as if it is shrouded in clouds. If vision is affected, descend immediately; continuing to ascend will only worsen the situation. Vision usually returns to normal within 4 to 6 weeks, and in rare cases vision is permanently affected.
Thrombosis
StrokeCerebral Vascular Accident
pulmonary Embolism??Pulmonary Embolism??
In high mountains, in addition to increased blood viscosity, hypoxia, dehydration, bad weather, reduced exercise, and increased red blood cell counts, blood clots (thrombosis) can form. Immobility due to frostbite can also lead to thrombosis.
A blood clot usually occurs in a blood vessel in the lower leg, usually after a long period of inactivity, such as being trapped in a camp in a snowstorm. Patients may experience pain in the inner thigh, behind the knee, swelling of the veins in the lower leg (Thrombophlebitis), and tenderness. The pain described above increases with walking, and it is often painful to pull the foot up. If the thrombus in the calf falls off and flows to the brain with the blood, it will block the cerebrovascular starvation and cause a stroke (Central Vascular Accident: CVA). .
Pulmonary Embolism (Pulmonary Embolism) occurs when a blood clot flows into the pulmonary artery.
Minor symptoms of pulmonary embolism:
·chest fullness
·frightened or dying
· Asthma
Symptoms of severe pulmonary embolism:
·Sudden chest pain, coughing, wheezing, rapid heartbeat
· Deep breathing can exacerbate lung pain
·Coughing up white, frothy fluid at first, but turning blood red after a few hours
·If a thrombus blocks a large blood vessel, it will die immediately
Prevention:
Prevention is very important, and it is much more difficult to wait until the onset of the disease.
·Keep your legs active when trapped in camp (a few minutes per hour)
·Avoid tight clothing
·Drink enough Don’t wait until you are thirsty to drink water, and don’t drink water because you are afraid of internal urgency (otherwise you may never have to go to the toilet, hehe)
· People with varicose veins do not Suitable for mountain climbing
Treatment:
·If thrombosis and phlebitis have developed, the patient should avoid exercise (to prevent the thrombus from falling off) and raise the feet slightly, loosening the tightness Clothes, lie down in a comfortable position, and stay hydrated
· take aspirin until symptoms resolve (usually 4 to 5 days)
· ;If you have to move, you can use elastic bandages to wrap the affected leg, and try to be carried by others
down the mountain. If you have symptoms of stroke or pulmonary embolism, it is a very serious event, and you should immediately evacuate and call for assistance.
High Altitude Systemic Edema (High Altitude Systemic Edema)
It is mainly caused by the accumulation of sodium and water in the body that cannot be excreted by the kidneys. This edema can occur independently and does not necessarily accompany symptoms of acute mountain sickness (AMS). Among them, women are more likely to be affected. While this condition can be disturbing, it is not fatal and will disappear naturally when back down.
Symptoms:
· swollen hands and feet, and swelling of face and lips in the morning
· less urination, even after drinking plenty of water; weight within a few days It will increase by about 4 kg
Treatment:
Avoid eating high-salt foods, follow the instructions of medical personnel familiar with altitude sickness, and take diuretics (Furosemide).
A few more words:
I hope you don??t ignore safety and proper knowledge while exploring, especially love to climb high (maybe you want to become a Tibetan wild ass) The “Mules”!
Many people who die from altitude sickness ignore some of the most obvious early symptoms. Especially don’t hide your symptoms for the sake of face, know that it is your responsibility to tell your teammates about your discomfort – otherwise you will end up dragging others down! In particular, pay attention to some guys who are usually aggressive, competitive, ambitious, respectful, have high self-esteem, and have good physical strength!