Saturday, 6 October 2012

WOTD: Barotrauma

Chest x-ray of Barotrauma in a patient with status asthmaticus. Photograph: realicu.com

"Barotrauma" - Damage or pain, mainly affecting the middle ear and facial sinuses, that is caused by changes in surrounding air pressure. Air travellers are at the greatest risk, but scuba divers face similar problems.

Aircraft cabin pressure decreases as the plane ascends and increases as it descends. As the aircraft ascends, the ears may "pop" as the air in the middle ear expands and is expelled via the eustachian tubes, which connect the middle ear to the back of the throat. On descent, the higher pressure may push the eardrum inwards and cause pain. Minor pressure damage in the middle ear may cause pain, hearing loss, and tinnitus for a few days; damage within the facial sinuses may also cause pain, and possibly a discharge of mucus or blood. Symptoms usually wear off within hours or days, but treatment may be needed if they worsen or persist. Large pressure changes can rupture the eardrum.

Barotrauma can be avoided by vigorous swallowing or by forcibly breathing out with the mouth closed, and the nose pinched (the Valsalva manoeuvre). This action equalises the internal and external pressures in the middle ear and sinuses. If the eustachian tubes are blocked, as commonly occurs with a cold, use of a nasal spray containing a decongestant drug is recommended shortly before the descent of the aircraft. 

"barotrauma". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p66.

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