High Altitude Pulmonary Edema (HAPE)
High altitude pulmonary edema (HAPE) is a life-threatening illness which occurs at high altitude. It develops from acute mountain sickness, more commonly known as altitude sickness . At higher altitudes the air pressure decreases and so the oxygen atoms are more spread out in air, this means that with each breath less oxygen is breathed in.
- High altitude pulmonary edema occurs at above 3000m due to people ascending in altitude too quickly without proper acclimatisation. It is caused by the alveoli in the lungs becoming hypoxic which leads to the vasoconstriction of the pulmonary blood vessels . This vasoconstriction causes an increase in capillary pressure and in turn an increase in hydrostatic pressure. The increase in capillary and hydrostatic pressure causes damage to capillary walls which leads to the edema. This negatively effects oxygen delivery as there is now an increased diffusion distance .
The symptoms of HAPE include two or more of the following:
- Blue skin
- Trouble with breathing, even at rest
- Tightness of the chest
- Tiredness and Weakness
- Rapid heart rate (tachycardia)
- Rapid shallow breathing
If an individual is experiencing these symptoms, they should either seek hyperbaric treatment, supplement oxygen or descend to a lower altitude as quickly as possibleto prevent the development of HAPE to the more serious high altitude cerebral edema (HACE) .