Medical Aspects Related to Freediving

Pages in this article 1  2   3   4   January 1, 2005 2:27 PM

We have gathered physiological and psychological aspects of freediving.

Table of contents
Barotrauma
Middle Ear Barotrauma
Lungs-Barotrauma
Swallow Water Blackout
Pool Blackout

Barotrauma

There are several cavities in the human body (e.g. sinus of the nose, frontal sinus, middle ear). Because the water pressure is increasing during the descend of a diver those cavities have to be equalized to adjust the inside-pressure to the water-pressure. Usually there are no problems and this happens automaticly, except middle ear (see Middle ear barotrauma). Problems may occur while diving with headcold or influenza. Then, due to a stuffed up nose or sinus the air cannot reach the sinus to equalize the pressure. The diver then may feel a sucking in the sinus and frontal sinus and blood issues from the mucous membrane and nosebleeds or even sinusitis can be the consequences.

Prevention of Barotrauma:
Don't dive when suffering from influenza, headcold, or sinusiti.

Middle Ear Barotrauma

Middle Ear Barotrauma is one of the most frequent diving injuries. It is the direct result of improper middle ear equalization. There is a connection between Middle Ear and throat - the Eustachian tube. When a diver is descending he has to equalize the middle ear through the Eustacian tube to adjust the middle ear pressure to the water pressure to prevent the eardrum from being injured.
The tube is approximately 1.5" long and is located in the back of the nasopharynx at approximately nostril level. The tube is normally closed and has a highly variable patency. This means that some individuals will virtually never have problems with middle ear equalization while diving. Others with narrow or partially obstructed Eustachian Tubes may have trouble equalizing their middle ears. These later individuals can dive safely, but for them middle ear pressurization requires meticulous attention to detail and much practice.
Fortunately, improper equalization draws attention to itself causing strong eardrum-ache. Pressurization of the middle ear provides a pillow of air behind the tympanic membrane, protecting the ear drum from barotrauma. As descent occurs, more air can easily enter an inflated Eustachian tube and pass into the middle ear, if pressurization begins early in the dive. If the Eustachian tube is allowed to collapse at any time during descent due to squeeze, the pressure to re-inflate it becomes greater. There are different techniques to equalize the middle ear. Here is a good summary

Prevention of Middle Ear Barotrauma:
Don't dive when suffering from influenza, headcold, or sinusitis.
Equalize your middle ear early in the dive.
Equalize your middle ear often.

Lungs-Barotrauma

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