Altitude Sickness

Mountain Sickness is divided into Acute Mountain Sickness(AMS) and Chronic Mountain Sickness(CMS).

Acute Mountain Sickness generally refers to a variety of symptoms that occur within a few hours to a few days when entering a plateau (above 2500 meters above sea level) from the plain without adaptation or quickly entering a higher altitude area from the plateau. Acute Mountain Sickness can be further divided into: acute mountain sickness, High Altitude Pulmonary Edema(HAPE), High Altitude Cerebral Edema(HACE), and the severity gradually deepens. The initial acute mountain sickness manifests as headache, fatigue, loss of appetite, nausea and vomiting, dizziness, and insomnia, but it is not fatal. But if left untreated, it may develop into HAPE. And then may slowly developed into HACE. HACE may not occur until at least two days after the altitude is above 4000 meters. Symptoms include unstable gait, trunk ataxia, lethargy, confusion, and some mild fever. If proper treatment is not taken, the coma may develop rapidly and even die from a brain herniation within 24 hours.

Chronic Mountain Sickness refers to chronic diseases such as the cardiovascular and cerebrovascular, blood system and other chronic diseases of people who live and work above 3000 meters above sea level for a long time due to low oxygen.

The treatment of Mountain Sickness is mainly to use hyperbaric oxygen therapy to assist drug treatment, and if necessary, lower the altitude and leave the plateau environment.

The principle of hyperbaric oxygen therapy is that hyperbaric oxygen can quickly correct hypoxemia in the body, improve and eliminate the hypoxic state of tissues, especially brain tissue, reduce pulmonary artery pressure, improve ventilation function. Hyperbaric oxygen can also constrict blood vessels, reduce tissue edema, especially reduce blood flow to the brain, reduce cerebral edema, reduce intracranial pressure, improve brain function, and promote recovery.

Here is an example. The patient is a 48-year-old man. On June 3, 2020, he traveled to Tibet by car from Qinghai with his friend, and arrived in Lhasa(about 3,600 meters above sea level) in only two days .On the next day, he developed symptoms of confusion during the day. He lost consciousness that night and was immediately sent to a local hospital for hyperbaric oxygen and fluid infusion therapy, but he did not improve significantly. He was sent to the People’s Hospital on June 9 and was diagnosed with HAPE and HACE. The doctor immediately sent him into a hyperbaric oxygen chamber for emergency treatment. After the first emergency hyperbaric oxygen treatment, the patient’s consciousness improved significantly when he exited the cabin.

So how to prevent altitude sickness? The first choice expect drug prevention is hyperbaric oxygen therapy. Hyperbaric oxygen can better stimulate the body’s endogenous protection mechanism, thereby reducing various adverse effects caused by entering the plateau. Secondly, the speed of entering the plateau cannot be too fast. And the way to prevent severe mountain sickness is to treat acute mountain sickness in time.

Warmly remind all friends that before going to the plateau, they must understand the relevant knowledge of plateau diseases, raise their awareness of danger, and be prepared to deal with it. After returning, hyperbaric oxygen can also be used to promote body recovery.