Apnea Halts Exchange Of Gases In The Lungs
When humans breathe, it is not only to bring oxygen into the system, but also to remove carbon dioxide. When apnea occurs, all muscles involved in the breathing mechanism are not working and essentially their breathing function stops. Voluntary apnea, such as when a person holds their breath or through mechanical means, such as strangulation or blocking the airways or it can be the result of an illness such as neurological disorder.
Since breathing is an automatic mechanism used by the body to insure an adequate supply of oxygen to the blood, when apnea occurs it can cause a build up of carbon dioxide in the blood stream. When the levels of carbon dioxide become too elevated, many of the body's systems can be affected, since the body does not store a low of oxygen. In some cases of apnea, even though breathing is not taking place, the exchange of oxygen and carbon dioxide between the lungs and the blood can still occur. However, after about one or two minutes the need for fresh oxygen will be come desperate.
The body may last about three to four minutes without the oxygen exchange of oxygen and carbon dioxide, but unless ventilation is restored, system in the body that relies on oxygen, such as the brain, may be damaged during long periods of apnea. After several minutes of lack of breathing, death is almost certain.
Mistaken Beliefs Can Be Deadly
Some misconceptions about voluntary apnea cause the belief that by hyperventilating before diving underwater and extend the time they can go without breathing. They may think that by taking several deep breaths prior to a dive they can go longer without drawing in a fresh breath. The reality is that the body does not allow for the additional oxygen to remain in the system, and while holding their breath underwater, the carbon dioxide still builds up in the blood.
It is not necessarily the lack of oxygen that can cause problems with voluntary apnea as much as it is the carbon dioxide that remains in the system. This has led to what are called shallow water drowning in which divers build up carbon dioxide in the blood causing unconsciousness and subsequent drowning, often in very shallow water.
Breathing is about the exchange of oxygen and carbon dioxide and anything that causes apnea, whether voluntary, mechanical or by illness can cause serious problems due to the lack of oxygen as well as the excess gases in the blood.
