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Chapter 30 — 2
Tympanic Membrane
Damage
This membrane can be torn by:
•
Excessive stretching
during descent (middle ear barotrauma). See Chapter 9.
• A
shock wave
passing down the ear canal, such as an
underwater explosion
or a
pressure
wave from a fin
passing close to the divers ear.
• An excessively forceful
Valsalva
manoeuvre has also been known to rupture the tympanic
membrane from within.
Fig. 30.1
Case History 30.1.
A diver swimming closely behind his buddy suddenly felt pain in his left ear as his buddy's
fin swept past his ear. Dizziness followed but soon settled. He surfaced and noticed a small amount of blood
coming from his ear.
Diagnosis:
Rupture of the ear drum caused by a pressure wave from a fin. The dizziness was due to cold water
entering the middle ear through the ruptured ear drum. The blood was extruded by gas expanding in the middle
ear, during ascent.
Case History 30.2
. An old professional hard hat diver who smoked cigarettes and had suffered repeated
tympanic membrane ruptures from barotrauma was in great demand at parties because of his ability to blow
smoke from his ears. He claimed that during the latter part of his career he no longer needed to equalise.
Diagnosis A:
Chronic perforation of the ear drums. His unusual talent was made possible by smoke passing
from his throat to his ears through the Eustachian tubes, after he takes a drag from the cigarette and performs a
Valsalva manoevre. His ears became self equalising later in his career because of permanent holes in his ear
drums. Although in demand at parties, unfortunately he often misheard the directions and turned up at the wrong
address.
Diagnosis B:
Poor hearing due to recurrent barotrauma and chronic perforation of tympanic membranes.