Middle Ear Barotrauma
This usually starts as a fullness or pressure that gets worse as the diver descends and improves on rising in the water. Pain ensues as the pressure differential rises or unless the diver is able to equalize. Some conductive hearing loss is present and there may be tinnitus and vertigo.With ear drum rupture, the pain is severe and there is usually associated vertigo as the water runs into the middle ear.
Signs are noted on examination and include edema and hemorrhage of the ear drum, retraction of the drum and collections of fluid in the middle ear. Various grades of severity are described as Teed Grade 0 through 5.
Type 1 Middle ear barotrauma (symptoms without signs)
Avoid diving until asymptomatic, can autoinflate both ears at the surface, until preexisting nasal problems have cleared. Systemic and topical nasal decongestants.
Type 2 Middle Ear Barotrauma
Signs and symptoms without perforationAvoid diving until complete resolution. Systemic and topical nasal decongestants. Prophylactic antibiotics. Systemic analgesics for pain relief.
Type 3 middle ear Barotrauma
Avoid further diving until ear drum has healed. Cleanse external auditory canal. Do not use ototoxic eardrops. Systemic and topical nasal decongestants. Antibiotics and referral to a surgeon if the ear drum does not heal in 1 to 2 weeks.
Prevention of Middle Ear Barotrauma (Article by Ed Kay, MD)
Descend feet first. This not only prevents venous congestion and swelling around the openings to the Eustachian tubes but allows observation of the diving partner, an impossibility during a headfirst descent. A diving problem can occur at any depth, and in most cases a diving partner (qualified) may be able to observe a problem onset and those perhaps reduce the risk to both parties.
Descend on the anchor line. This allows for minute up and down control while clearing and descending.
Don’t dive after taking medication that causes nasal congestion. Examples are certain blood pressure and prostate medications. (Hytrin).
Commercial airline passengers sometimes experience barotrauma of the middle ear that requires treatment by a physician. A recent article by Thomas P. Brown, a US Navy physician, explains how such trauma occurs, how it can be prevented, and how it should be treated. The information can be interpolated to apply to divers–just reverse the sequence.
During aircraft ascent, ambient pressure decreases slowly, causing the tympanic membrane to bulge outward. When the pressure differential reaches 15 mm Hg — approximately every 122 m (400 ft) in increased altitude — the properly functioning eustachian tube vents the positive pressure. On descent, the ambient pressure increases; the tympanic membrane bulges inward, and the eustachian tube resists the positive inward flow. Passengers experience discomfort when the differential reaches 60 mm Hg. At 90 mm Hg, the eustachian tube locks up, preventing the equalization of pressure by whatever means. A 100- to 500-mm Hg differential causes the tympanic membrane to rupture, relieving the pain but often resulting in vomiting, loss of hearing, dizziness, and vertigo.
During barotrauma, the tympanic membrane becomes distorted with respect to color, shape and integrity. As barotrauma progresses, the tympanic membrane mucosa becomes edematous, there is hemorrhaging, and a transudate forms in the middle ear. The tympanic membrane sometimes ruptures because of weakness of the tympanic membrane, inadequate transudate or hematoma formation, or too rapid a change in pressure.
The most effective means of combating middle ear block is to avoid flying while experiencing upper respiratory tract infection. Passengers should yawn, chew, or swallow — activities that open the eustachian tube momentarily and allow for pressure equalization. Valsalva’s maneuver, taking a small breath, holding the nose, and attempting to force air through the closed nostrils, is especially effective in equalizing pressure during descent. If flying in a small plane with few passengers, the pilot may be asked to reascend.
One hour before takeoff and again 30 minutes before, two puffs of oxymetazoline hydrochloride will constrict the arterioles of the nasal mucosa, permitting the eustachian tube to function efficiently. Oral decongestants (e.g., pseudoephedrine and phenylpropanolamine), which affect areas that sprays don’t reach, may be initiated 1 or 2 days before a flight. Newer antihistamines without sedating effects may also be effective. Severe or unremitting earblock may be treated by a physician using a Politzer bag. With the patient seated, one nostril is occluded and the flange of the bag is inserted into the other nostril. While the patient rapidly repeats the letter K or takes small sips of water, the bulb is compressed. The Politzer bag is effective in clearing ear block in 50% of cases. If the patient has excruciating pain or still has earblock after one week of the treatments described, myringotomy may be required.
(Brown T. Postgrad Med. 1994; 96: 135-142.)
External Ear Canal Barotrauma (External Ear Squeeze)
Surfer’s Ear (Bony exostosis)
This is a blockage of the inner portion of the ear canal by a bony growth called exostosis. This is more commonly seen in surfers, but occasionally can be seen in cold water divers. It is thought to be due to the cooling effect of evaporating water on surfers – and on the effect of cold water on divers. It can cause problems in divers by blocking the egress of cerumen and thus the canal, producing the possibility of an external ear squeeze, decreased ability to ewqualize, alternobaric vertigo and caloric vertigo.
Prevention is by the use of ear plugs in surfers and hoods or vented ear plugs in divers. Definitive treatment is by an operative procedure called canalectomy – or the excision of the bony area of the ear canal that is blocking the canal.
Prevention of Otitis Externa
Cleanse external canals of occluding wax and avoid trauma from Q-tips, bobby pins, etc. Use a good ear solution to maintain a slightly acid environment. A 2% acetic acid and aluminum acetate solution is a good choice. (The pharmacist either can make this up or provide a generic solution; ‘Domeboro Otic Solution is not made or sold by Bayer any more.)
Treatment of Otitis Externa
Irrigate with lukewarm tapwater or 1.5% peroxide. Eardrops that are slightly acid or contain antibiotics.
Transient Vertigo Resulting from Unequal Middle Ear Pressure Equilibration (Alternobaric Vertigo)
This is dizziness resulting from unequal pressures. It is due to unequal increase in middle ear pressures on ascent.
Transient Vertigo Resulting from Caloric Stimulation
A similar vertigo can also occur as a result of unequal caloric stimulation of one labyrinth over the other due to diving in a prone position in cold water–the undermost ear being stimulated.
Transient Dizziness Resulting from HPNS High Pressure Nervous Syndrome
Alternobaric Facial Paralysis
The facial nerve traverses a canal very close to the middle ear. Middle ear over-pressure can cause damage to this nerve resulting in a one-sided facial paralysis. It is often associated with alternobaric vertigo. The paralysis is temporary.
Chronic Ear Dysfunction In Diving
Inner Ear Injuries Related to Middle Ear Barotrauma During Descent or Compression Inner Ear Barotrauma
Pathophysiology of Inner Ear Barotrauma
This is thought to be due to implosive or explosive rupture of the round or oval windows in relation to diving stresses. Straining or valsalva maneuvers in attempts to clear the ears increases the pressure differential between the middle ear and the labyrinth to the point of rupture.
Surgery for Inner Ear Barotrauma
There is a debate as to the proper management of the perilymph fistula. Some feel that it should be operated upon immediately (Pullen). Some feel that watchful waiting should be done with operative closure of the perilymph fistuls done only when there is no improvement after 48-72 hours of bedrest with head elevated. Most authors advise an initial trial of medical management and that surgery should be undertaken on those who don’t improve after 5 to 10 days or if inner ear function worsens in the meantime.
Otologic Problems Occurring at Stable Depth
Three divers experienced this in a chamber dive after changing from helox to a gas containing neon or nitrogen at depth. Vertigo, nausea, nystagmus were experienced and permanent end-organ damage was demonstrated in two of these divers.
Inner Ear Decompression Sickness
This is related to nitrogen bubble formation in the labyrinthine vasculature.
Human Reports of Inner Ear Decompression Sickness
Buhlmann, A, Waldvogel W: The treatment of decompression sickness. Helv Med Acta 33:487-491.1967Rubenstein CJ, Summitt Jk:Vestibular Derangement in decompression. In Lambertsen CJ (ed):Underwater Physiology. Proceedings of the Fourth Symposium on Underwater Physiology. New York. Academic press. 1971, pp. 287-292.
Management of Inner Ear Decompression Sickness
1. Manage as decompression sickness with prompt recompression when encountered early after a dive.
2. Switch back to helium-oxygen if the problem is due to switching to air in decompression from a deep exposure.
3. Recompression to 3 ATM deeper than the depth at which the symptoms occurred or to table depths suitable for the treatment of neurological decompression sicikness.
4. Fluid replacement, oxygen administration with avoidance of anticoagulants, low-molecular weight dextran, steroids, aspirin and salicylates should be accomplished.
5. Diazepam (Valium), 5 to 15 mg is effective in relieving the vertigo, nausea and vomiting.
6. Documentation of otoneurologic symptoms as soon as possible.
7. No return to diving if permanent inner ear dysfunction ensues.
Differential Diagnosis of Inner Ear Barotrauma and Inner Ear Decompression Sickness
This is important in that the treatment is entirely different. Recompression is necessary for inner ear DCS while it is contra indicated for inner ear barotrauma.
Factors helpful in the differential:
1. Time of onset–symptoms occurring during compression (Descent) indicate possible barotrauma. Those symptoms occurring shortly after decompression (ascent) are more likely related to DCS.
2. History of the dive profile— shallow, air dives more likely barotrauma. Deeper, mixed gas diving–more likely DCS.
3. Associated symptoms of barotrauma, such as pain, fullness, blockage with barotrauma; joint, skin or neurological problems with DCS.
4. Physical findings associated with barotrauma,ear drum findings: skin and neurological findings with DCS.