1. Otitic barotraumas & otitic
decompression illness
Otitic barotrauma
Barotrauma is an injury produce by a change of pressure in a gas-filled space. Otitic barotrauma is a
pathological conditions of the ear induced by pressure changes.
Physiological consequencies of compression(descent)
Eustachian tube passive egress of air from middle ear to the pharynx if the middle ear pressure is
high. In reverse situation, where nasopharyngeal air pressure is high, air can not enter the middle
ear unless tube is actively opened by the contraction of muscles as in swallowing , yawning &
Valsalva manoeuvre. When atmospheric pressure is higher than that of middle ear by critical level of
90mm of Hg eustachian tube gets locked.
In presence of Eustachian tube oedema, even in small pressure difference locking of the tube occur.
Negative pressure in the middle ear causes transudation or blood, then even rupture of the
tympanic membrane occurs.
Inner ear barotrauma; negative middle ear pressure> retraction of the tympanic membrane>
resultant inward force on the foot plate of stapes via ossicles> corresponding bulging of the round
window membrane into middle ear> sufficient pressure generated to cause round window
membrane rupture.
Physiological consequences of decompression (ascent)
During ascent, as the middle ear pressure exceeds that of the ambient pressure, passive ventilation
of air through the Eustachian tube into pharynx occurs.
During a diver’s decent(for the aviator, during the previous flight) mild middle ear barotrauma may
occur due to suboptimal Eustachian tube function, resulting mucosal oedema & possibly
haemorrhage. As a result the usual passive ventilation,which should occur during subsequent ascent,
can no longer take place. To continue ascending in these circumstances would result in a relatively
positive middle ear pressure compared to the ambient pressure, causing outward bulging of the
tympanic membrane.
Inner ear barotrauma: By similar mechanisms to those described during decent , reverse effect on
the oval window & round windows may be seen.The tympanic membrane is pushed outwards &
hence a traction force is applied to the oval window via the ossicles. This is accompanied by an
inward force on the round window membrane. It is possible to occur perilymphatic fistula.
A sudden outflow of air down the Eustachian tube is sometimes decribed,immediately followed by
the symptoms& signs of a perilymphatic fistula.

2. Clinical features of otitic barotrauma
1)Compression(descent) injuries
2)Injuries at the stable pressure;
3) decompression(ascent) injuries.
Compression(descent) injuries
1.external ear barotraumas/reverse ear: external ear barotraumas occurs when a pocket of air is
tapped within the external auditory canal. This may be cerumen, earplugs,foreignbody or exostoses.
If the Eustachian tube function is normal, then with increasing compression the pressure of the
trapped meatal air becomes negative compared to that of the middle ear & the external ambient
pressure. As result, the pressure gradient across the tympanic membrane results in it being
displaced outwards. If this is with sufficient force, the perforation may occur.
Main symptom is of pain, increasing with depth. The ear canal skin& tympanic membrane become
injected & petechial haemorrhages & even bleeding may occur.
2. middle ear barotrauma: middle ear barotruama is the most frequent pressure-induced ear
trauma. Initial symptoms is the sensation of a blocked ear with a strong desire to equalize. This
progress to the predominant symptom of otalgia.
Tympanic membrane appearance in middle ear barotrauma
Grade Symptoms/ signs
0 Symptoms present but no sign
1 Redness & retraction
2 Intratympanic membrane haemorrhge
3 Gross tympanic membrane haemorrhage
4 Haemotympanum
5 Perforation
Treatment : when significant signs but no perforation are present, conservative treatment with
either oral or topical decongestants. Myringoplasty is indicated in those fail to heal spontaneously.
3.Inner ear barotrauma : three pathological entities inner ear resulting from compression
barotruama. These are:
a) inner ear haemorrhage;
b) labyrinthine membrane tears;

3. c) perilymphatic fistula.
a) Inner ear haemorrhage: this gives transient , minimal , vestibular symptoms & mild to moderate
sensorineural hearing loss. A good recovery would be expected.
b) Labyrinthine tears :these may induce similar symptoms but any loss is permanant. Patient may
present with symptoms closely resembling those of an acute Meinere’s disease attack, with vertigo
& tinnitus, low frequency hearing loss often at 1-2 kHz. Temporal bone studies have demonstrated
Reissener’s membrane rupture as well as rupture of the utricle & saccule.
Occluded ear: By studying the speed of both compression & decompression with one Eustachian
tube occluded, it has been found that in the occluded ears rapid compression(descent) causes more
hair cell damage than do rapid decompression.
Non-occluded ear: In the normally ventilated ears, the inner ear more susceptible to
decompression(ascent) trauma.
c) Perilymphatic fistulae: a typical history is one of difficulty equalizing the middle ear pressure
during descent, when either diving or flying resulting in a rigorous Valsalva’s manoeuvre being
attempted. There is sudden onset of vertigo,accompanying hearing loss & often tinnitus.
A perilymph fistula is suspected in an otherwise healthy ear ( or in one with evidence of middle ear
barotrauma if there is a sensorineural hearing loss of rapid onset, constant disequilibrium, positional
nystagmus, Tullio phenomenon( momentary vertigo or disequilibrium with exposure to sudden loud
noise), a positive fistula sign& tinnitus.
Treatment :
-steroids for moderate to severe hearing losses.
- immediate surgical exploration if short presentation & moderate/ severe hearing loss.
- surgical exploration for progressive hearing loss/ persistent disequilibrium.
-close obvious fistulae if unclear the cover both windows with vein adventitia.
Advice to the patient:
-scuba driving contraindicated if persistent problems.
-decongestants before flying/diving;
- beware of lifting/straining/flying six weeks post-operatively.