High altitude pulmonary oedema results from the leakage of fluid to the air sacs of the lungs from the capillaries, preventing effective oxygen exchange.
High altitude pulmonary oedema, also called HAPE, results from the leakage of fluid to the air sacs of the lungs from the capillaries when at high altitudes. As a results of fluid leakage, effective oxygen exchange is obstructed. In severe cases, it can be fatal. It is considered a major, more severe form of High Altitude Illnesses (HAI), along with High Altitude Cerebral Oedema (HACE).
The main cause of HAPE is the decreased oxygen concentration. Most people are accustomed to 21% oxygen concentration at sea level. As the altitude increases, although the concentration remains the same, the number of oxygen molecules per breath is reduced. HAPE occurs as blood pressure in the lungs rises as a response to the low oxygen levels. Some areas of the lung cannot contain high pressure, resulting to the breakdown of the small blood vessels, leading to fluid leakage across the membranes into the air sacs.
Risk Factors for High Altitude Pulmonary Oedema (HAPE)
Anyone is at risk for developing high altitude pulmonary oedema, but the following factors increases an individual’s to develop the illness. These factors include:
- Not properly acclimatized
- Genetic makeup
- Certain pre-existing lung and heart conditions
- History of high pulmonary artery pressure
- Previous history of HAPE
- Going to high altitudes with a respiratory infection, especially children
- Gender: male
Symptoms of High Altitude Pulmonary Oedema (HAPE)
Most symptoms of HAPE begin to manifest after the first two to four days at altitude. The most common symptoms include:
- Shortness of breath with exercise that progresses to occur even at rest as fluid accumulates in the air sacs
- Decreased exercise performance
- Cough with or without blood, or with pink or frothy sputum
- Cyanosis of the lips or fingernails
- Tightening of the chest or congestion
- Severe weakness
- Extreme fatigue
- Drowsiness
- If left untreated, loss of consciousness, coma, and even death
First Aid Management for High Altitude Pulmonary Oedema (HAPE)
HAPE is considered a medical emergency that requires immediate action. Administer first aid at all cases to prevent complications from developing:
- It is mandatory to descent to a lower altitude in all cases of HAPE.
- Give oxygen to the casualty to increase oxygen levels in the blood while decreasing the pressure in the lung blood vessels. In cases wherein supplemental oxygen is not available, do not delay descent.
- The casualty is advised to rest and stay hydrated at all times.
- In some cases, medications such as Dexamethasone, Acetazolamide, and nifedipine are given.
- If descent is not possible, place the patient in a portable hyperbaric chamber (Gamow bag) for 4-6 hours.
Disclaimer: This article does not provide medical advice and should not be substituted for formal training. The information given should not be used for self-diagnosis. Seek medical attention when necessary. It is important to recognise medical emergencies at all times to avoid complications from developing. To learn more about to how to manage high altitude pulmonary oedema and other high altitude illnesses, enrol in First Aid Courses and CPR Courses with St Mark James Training.
Online Sources:
http://www.altitudemedicine.org/index.php/altitude-medicine/learn-about-altitude-sickness/what-is-hape
http://www.basecampmd.com/expguide/hape.shtml
http://www.princeton.edu/~oa/safety/altitude.html