ALTITUDE ILLNESS
AMS
Acute mountain sickness (AMS) is a common condition that can occur when individuals ascend to high altitudes too quickly, typically above 8,000 feet (2,500 meters). It is caused by reduced oxygen levels and lower atmospheric pressure at high altitudes, which can lead to various symptoms.
The signs and symptoms of AMS usually appear within 6 to 12 hours of reaching a high altitude and can include headache (typically throbbing and worsening with movement), nausea, vomiting, loss of appetite, fatigue, dizziness, difficulty sleeping, and a general feeling of unwellness. These symptoms may be mild to moderate and often resolve on their own within 24 to 48 hours as the body acclimatizes to the altitude.
Prevention of AMS involves gradual acclimatization to high altitudes. Ascending slowly and spending a few days at intermediate elevations allows the body to adapt to lower oxygen levels. Hydration is crucial and maintaining adequate fluid intake is important as your body needs extra fluid to adapt. Avoiding alcohol consumption and certain medications that can impair judgment at high altitudes is advised. If individuals have a history of AMS, they may benefit from pre-treatment with acetazolamide or other preventive measures recommended by healthcare professionals.
Treatment for AMS involves several key strategies. The first and most important step is to rest and allow the body time to acclimatize to the altitude. It is advised to avoid further ascent until symptoms improve. Drinking plenty of fluids, preferably water, can help prevent dehydration and alleviate symptoms. Over-the-counter pain medications, such as acetaminophen (Tylenol) or ibuprofen can be used to manage headaches. It is essential to avoid alcohol and certain medications that can worsen symptoms or impair judgment at high altitudes.
If symptoms worsen or persist despite these measures, descending to a lower altitude is recommended. Descending by at least 1,000 to 2,000 feet (300 to 600 meters) can significantly improve symptoms. If descent is not immediately possible, supplemental oxygen can be administered to provide relief. Portable hyperbaric chambers (Gamow bag), which simulate lower altitudes may also be used to treat AMS in certain situations.
There are two medications that can be prescribed for both the prevention of AMS and the treatment. Acetazolamide, a diuretic, is commonly prescribed for AMS prevention and treatment. It helps stimulate breathing and increase oxygenation. This medication is typically started before ascent and continued until descent or after 2 to 3 days at maximum altitude. The other medication is dexamethasone. This medication is a steroidal anti-inflammatory and can be taken orally or as an intramuscular injection. Dexamethasone is only recommended for moderate to severe AMS.
{ DISCLAIMER}- It's important to note that while AMS is generally a mild and self-limiting condition, it can progress to more severe illnesses, such as HACE or HAPE, which require immediate medical attention. If you or someone you know is experiencing severe symptoms or symptoms that are not improving, it is vital to seek prompt medical care from a healthcare professional.
Gallagher, SA., Hackett, P. Acute mountain sickness and high-altitude cerebral edema. In: UpToDate, Danzl, DF(ed), UpToDate, Waltham, MA, 2023.
HAPE
High altitude pulmonary edema (HAPE) is a potentially life-threatening condition that occurs at high altitudes, typically above 8,000 feet (2,500 meters). It is a form of altitude illness characterized by the accumulation of fluid in the lungs. HAPE is primarily caused by reduced oxygen levels and lower atmospheric pressure at high altitudes, leading to increased pressure in the pulmonary blood vessels and leakage of fluid into the lungs.
The signs and symptoms of HAPE usually develop within two to four days of arrival at high altitude. Early symptoms may include shortness of breath during physical exertion, coughing, weakness, fatigue, and chest tightness. As HAPE progresses, symptoms can worsen and may include extreme shortness of breath even at rest, rapid breathing, coughing up frothy or pink-tinged sputum, pale or bluish skin, and a rapid heart rate.
Immediate descent to a lower altitude is the most effective treatment for HAPE. This allows the body to receive more oxygen and reduces the strain on the lungs. In severe cases, where immediate descent is not possible, supplemental oxygen, portable hyperbaric chambers, or medications may be used to stabilize the individual until evacuation is possible.
Nifedipine, a medication used to treat high blood pressure, can be used in the treatment of HAPE. It helps to dilate the blood vessels and reduce the pressure in the pulmonary circulation, thereby reducing fluid leakage into the lungs. Nifedipine can be administered orally or as a sublingual tablet.
Prevention is crucial in managing HAPE. Gradual acclimatization to high altitudes, allowing the body time to adjust, is important. Ascending slowly and spending a few days at intermediate altitudes before reaching higher elevations can help reduce the risk. Hydration is essential as well, so maintaining adequate fluid intake is advised. Avoiding excessive alcohol consumption and certain medications that can impair judgment at high altitudes is also recommended.
{ DISCLAIMER}- It’s important to note that the information provided here is for educational purposes only. If you or someone you know is experiencing symptoms of HAPE or any other medical condition, it is vital to seek immediate medical attention from a healthcare professional.
Gallagher, SA., Hackett, P. High-altitude pulmonary edema. In: UpToDate, Danzl, DF(ed), UpToDate, Waltham, MA, 2023.
HACE
High altitude cerebral edema (HACE) is a severe and potentially life-threatening condition that occurs at high altitudes, typically above 8,000 feet (2,500 meters). HACE is primarily caused by reduced oxygen levels and lower atmospheric pressure at high altitudes, leading to swelling and fluid leakage in the brain.
The signs and symptoms of HACE usually develop gradually and may include severe headache, confusion, disorientation, loss of coordination, drowsiness, hallucinations, difficulty walking, and ultimately, loss of consciousness and death. These symptoms can be mistaken for other conditions, but it's crucial to recognize and address HACE promptly, as it can rapidly progress and be fatal if left untreated.
The treatment of HACE involves descending to a lower altitude as soon as possible. This allows the body to receive more oxygen, reducing the swelling in the brain. It is essential to descend at least 3000 feet (1000 meters) to effectively manage HACE. Additionally, administering supplemental oxygen can help alleviate symptoms during the descent. Prompt medical attention is crucial, and affected individuals should be evacuated to a lower altitude and seek professional medical care immediately.
Dexamethasone, a corticosteroid, is commonly used as part of the treatment for HACE. It helps to reduce brain swelling and inflammation. The medication is usually administered orally or through an injection. Dexamethasone can be given to individuals suspected of having HACE before they descend to a lower altitude, as it can provide temporary relief until descent is possible.
Prevention is key when it comes to HACE. Gradual acclimatization to high altitudes, allowing the body time to adjust, is essential. This involves ascending slowly and spending a few days at intermediate altitudes before reaching higher elevations. Hydration is crucial as well, so maintaining adequate fluid intake is important. Avoiding excessive alcohol consumption and certain medications that can impair judgment at high altitudes is also advised.
{ DISCLAIMER}- It’s important to note that the information provided here is for educational purposes only, and if you or someone you know is experiencing symptoms of HACE or any other medical condition, it is essential to seek immediate medical attention from a healthcare professional.
Gallagher, SA., Hackett, P. Acute mountain sickness and high-altitude cerebral edema. In: UpToDate, Danzl, DF(ed), UpToDate, Waltham, MA, 2023.
Acetazolamide (Diamox)
Diamox, also known by its generic name acetazolamide, is a medication commonly used to prevent and treat acute mountain sickness when traveling to high altitudes. It belongs to the class of drugs known as carbonic anhydrase inhibitors. Diamox helps to reduce the symptoms of AMS by promoting increased ventilation and improving oxygenation in the body. It helps the body acclimatize to higher altitudes more efficiently.
Reactions to Diamox can vary among individuals. Common side effects may include tingling sensations in the fingers and toes, frequent urination, and mild gastrointestinal disturbances. In some cases, people may experience more severe reactions, so it's essential to consult a healthcare professional before taking Diamox, especially if you have any pre-existing medical conditions or are taking other medications.
The timing of when to take Diamox is an important consideration. In general, it is recommended to start taking Diamox one to two days before ascending to high altitudes. This allows the medication to take effect and help prevent AMS from developing. The usual dosage is 125 mg (if under 100 kg) or 250 mg (if over 100 kg) every 12 hours for prevention and 250mg every 12 hours for treatment of AMS.
As with any medication, it's crucial to follow the prescribed dosage and directions provided by a qualified healthcare professional. Diamox can be a helpful tool in preventing altitude sickness, but it should not be seen as a substitute for proper acclimatization, gradual ascent, and other preventive measures. If you are planning to travel to high altitudes and are concerned about altitude sickness, consult with a healthcare professional to determine if Diamox is a suitable option for you and to receive personalized advice on managing altitude-related health concerns.
Gallagher, SA., Hackett, P. Acute mountain sickness and high-altitude cerebral edema. In: UpToDate, Danzl, DF(ed), UpToDate, Waltham, MA, 2023.
Dexamethasone
Dexamethasone is a corticosteroid medication commonly used to prevent and treat high-altitude illnesses, such as high-altitude cerebral edema (HACE). It belongs to a class of drugs called glucocorticoids and has potent anti-inflammatory properties. Dexamethasone helps reduce brain swelling and inflammation in HACE.
Reactions to dexamethasone can vary depending on the individual and the dosage used. Common side effects may include increased appetite, weight gain, mood changes, difficulty sleeping, and mild gastrointestinal disturbances. Like any medication, dexamethasone can have more severe side effects, especially if used in high doses or for extended periods. It's essential to use dexamethasone under the guidance and supervision of a qualified healthcare professional.
The timing of when to take dexamethasone is crucial in the context of high-altitude illnesses. If you suspect the onset of symptoms related to HACE, or if you are at risk due to rapid ascent to high altitudes, dexamethasone can be used as part of the initial treatment. It can provide temporary relief while arranging for immediate descent to a lower altitude, which is the definitive treatment for these conditions.
As with any medication, dexamethasone should only be taken under the direction of a healthcare professional. The dosing and duration of treatment will be tailored to the specific situation and the individual's medical history. It is not recommended for routine prophylaxis for all individuals ascending to high altitudes, and it should be reserved for emergency situations where HACE is suspected or diagnosed.
In summary, dexamethasone is a powerful medication used to treat high-altitude illnesses like HACE. It helps reduce brain swelling. Reactions to dexamethasone can occur, and its use should be supervised by a healthcare professional. It is not a substitute for proper acclimatization and gradual ascent at high altitudes. If you are planning to travel to high altitudes or have concerns about altitude sickness, seek medical advice to determine if dexamethasone or other preventive measures are appropriate for you.
Gallagher, SA., Hackett, P. Acute mountain sickness and high-altitude cerebral edema. In: UpToDate, Danzl, DF(ed), UpToDate, Waltham, MA, 2023.
