Hyperventilation
Hyperventilation in aviation is generally caused by panic or anxiety. It is important to understand it as it could happen to a pilot or a passenger.
What is Happening
When some people experience stress, they may begin to breath rapidly. Additionally, hyperventilation itself can be a stressful experience, leading to more hyperventilation. The diagram below outlines the "hyperventilation cycle"
Carbon Dioxide Expulsion
When hyperventilating, the body rapidly expulses carbon dioxide. With a normal breath rate (approx. 12 breaths per minute), the body produces the same amount of carbon dioxide as it is releasing through the lungs.
As the concentration of carbon dioxide decreases in the body, blood pH increases from its normal level and becomes alkalotic. This increase in pH is what causes the symptoms of hyperventilation.
Symptoms
Symptoms of hyperventilation include:
- Lightheadedness
- Shortness of breath
- Chest pain
- Fast and pounding heartbeat
- Numbness and tingling in arms or around mouth
- Muscle spasms
- Difficulty focusing
- Burping or bloated stomach
- Dry mouth
- Headache
Treatment
Hyperventilation should be treated by addressing both the stress that caused it and the breathing rate directly. Treatments include:
- Distracting someone away from the cause of stress
- Encouraging slow breathing
- Having someone breath into a bag
- Using supplemental oxygen set to the maximum setting