Updated: Dec 30, 2020
Hypoxia can creep up on pilots and cause very dangerous situations. It is important to know the causes of Hypoxia and its symptoms.
Here's what you need to know.
WHAT IS HYPOXIA?
Hypoxia means "reduced oxygen" or "not enough oxygen." Although any tissue will die if deprived of oxygen long enough, the great threat to pilots is its effects on mental functions while flying.
TYPES OF HYPOXIA
There are 4 types of hypoxia (or causing sources), what are they?
Is a result of insufficient oxygen available to the body as a whole. The most common cause of this in the aviation industry is the partial pressure of oxygen at higher altitudes. Essentially, at higher altitudes, the oxygen molecules are spread further apart. This can result in the body being unable to inhale enough oxygen to maintain certain mental functions.
Is a result of the body's blood cells not being able to take up and transport oxygen molecules to the brain. The most common cause of Hypemic Hypoxia, while flying, is CO (Carbon Monoxide) poisoning. This is because CO can attach itself to blood cells 200 times faster than oxygen. This means, the blood cells will be transporting CO to the brain instead of the necessary oxygen molecules.
Is a result of the blood not flowing to the brain. While there may be enough oxygen in the environment, and that oxygen is attaching to the body's blood cells, there may still be symptoms of Hypoxia if the blood is not flowing to the brain to deliver those oxygen molecules. In flying, this is most commonly found while pulling excessive accelerations of gravity (G-Forces). During G-Forces, blood may pool in the lower extremities of the body, preventing it from flowing to the brain.
Is the result of the brain rejecting oxygen molecules that are being delivered by the body's blood cells. This can be caused by drugs and alcohol. It is important to avoid alcohol and certain prescription drugs when preparing or performing flight operations.
SYMPTOMS OF HYPOXIA
Cyanosis (blue fingernails and lips)
Decreased Response Times
Tingling in the Fingers and Toes
Descend to a Lower Altitude
Put on an Aviation Approved Oxygen Mask
Stop Pulling G-Forces
Author - Nate Hodell
CFI/CFII/MEI/ATP - Creator of wifiCFI - Owner of Axiom Aviation Flight School.
This information is included in the Aeromedical Factors Lessons on wifiCFI. Sign up today to watch videos, listen to podcasts, take lesson quizzes, join live webinars, print lesson quicktakes, and more by clicking this link >