Is It Safe for Infants to Travel to High Altitudes? - Pediatrics

Dr. Pei Rensheng reply Pediatrics

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Dear Ah-Chih,
Hello! The speed of ascent, the altitude reached, the individual's level of physical training, and each person's unique physiological characteristics are the four main factors determining the occurrence and severity of altitude sickness (also known as acute mountain sickness, AMS).
Age and gender have little influence on this condition.
Altitude sickness is an acute pathological change that occurs in the human body due to reduced oxygen concentration at high altitudes.
It typically appears at elevations above 2,500 meters (approximately 8,000 feet).
Altitude sickness can progress to high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE), which can be fatal in severe cases.
The likelihood of different individuals experiencing altitude sickness varies.
Some healthy individuals may exhibit symptoms at elevations as low as 1,500 meters.
Locations such as the Tibetan Plateau (average elevation 4,500 meters), Lhasa (3,650 meters), Taiwan's Central Mountain Range, Yushan Mountain Range, and Xueshan Mountain Range (average elevation 3,000 meters), as well as Mexico City (2,240 meters), are all above this threshold.
However, most symptoms occur at elevations above 2,500 meters.
Consuming more carbohydrate-rich foods can alleviate these symptoms, as carbohydrates require less oxygen for oxidation compared to fats.
HAPE and HACE are the most severe manifestations of altitude sickness, while milder symptoms may include retinal hemorrhage and peripheral edema.
Altitude sickness commonly occurs during rapid ascents, so gradual elevation gain is a preventive measure.
In most patients, symptoms are often temporary and resolve as the body acclimatizes.
Headache is usually the primary symptom, typically starting above 2,400 meters, and may be accompanied by the following symptoms:
- Nausea or vomiting
- General weakness
- Dizziness or a feeling of lightheadedness
- Insomnia
Early symptoms include fatigue and general weakness, especially during strenuous climbing, which may progress to headaches, insomnia, persistent tachycardia, nausea, and vomiting (particularly in children).
Severe symptoms may include confusion, acute psychosis, hallucinations, and persistent cough due to pulmonary edema, potentially leading to seizures and coma.
The most severe symptoms of altitude sickness are caused by edema.
At high altitudes, the body may experience either pulmonary edema or cerebral edema.
The accompanying symptoms can be life-threatening, and the pathological reasons for edema remain unclear.
Individuals with colds who do not receive timely treatment may exacerbate altitude sickness, leading to pulmonary edema.
Therefore, it is crucial to take cold medication at the first sign of a cold to mitigate altitude sickness.
For pulmonary edema, corticosteroids (such as dexamethasone) can temporarily relieve symptoms while awaiting medical assistance.
Once individuals ascend to 3,000 meters, there is a 2% chance of developing HAPE, which can rapidly worsen and be fatal.
Symptoms include exhaustion, breathlessness even at rest, dry cough, and the presence of pink frothy sputum.
Descending to lower altitudes can alleviate these symptoms.
HACE is also a life-threatening condition, occurring in about 1% of individuals at elevations of 2,700 meters.
Symptoms include headache, exhaustion, blurred vision, bladder dysfunction, loss of coordination, unilateral weakness, and confusion.
Descending to lower altitudes can similarly relieve these symptoms.
Acclimatization is the body's gradual adaptation to increased altitude and reduced oxygen levels, which can help prevent altitude sickness.
Once above 3,000 meters, most climbers should adhere to a golden rule: "Climb high, sleep low." This means that climbers should camp at lower elevations and return to lower camps for rest after each summit attempt.
Each subsequent camp can gradually ascend, but the important principle is not to increase altitude by more than 300 meters in a single day.
Therefore, climbers can ascend from 3,000 meters to 4,500 meters in one day, but must return to at least 3,300 meters to sleep.
Treatment with a diuretic, Acetazolamide, can help the body acclimatize more quickly and treat mild symptoms of altitude sickness.
The Aymara indigenous people chew coca leaves to alleviate altitude sickness symptoms.
Tibetan medicine, particularly "Rhodiola," is also believed to help with altitude sickness and is a primary ingredient in certain herbal capsules for high-altitude health.
Additionally, drinking plenty of fluids can help counteract fluid loss caused by breathing cold, dry air at high altitudes.
Patients can relieve mild altitude sickness symptoms by taking rapid, deep breaths at a rate of 10 to 12 times per minute.
However, overdoing this may lead to peripheral numbness.
Other treatment methods include administering corticosteroids for pulmonary edema or using a pressure chamber for severe cases.
The most effective treatment for these symptoms is to transport the patient to lower altitudes as soon as possible.
For severe altitude sickness, a Gamow bag can be used, which is equivalent to descending 1,500 meters in altitude.
A Gamow bag is a plastic bag inflated with a foot pump that provides pressurized air for the patient to breathe.
This information is primarily sourced from Wikipedia.
Wishing you health and happiness!
Sincerely,
Dr.
Pei Ren-Sheng
Director of Pediatrics, Taoyuan Hospital, Department of Health

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Reply Date: 2009/02/09