ENT Anatomy

The Ear

The external ear canal is a blind tube ending with the ear drum. The cerumen, or wax, is slightly acid and has a protective function. The ear drum has evolved to vibrate with sound waves in the air which is present on both sides. Herein lies the problem with diving –the air-filled space inside the ear drum has to have pressure equalized as a diver goes down and up in the water column. This can only be accomplished without pain and damage by air passing back and forth through the Eustachian tubes. These tubes are easily blocked by problems in the back of the nose.

Middle Ear

Inner ear
The inner ear consists of fluid-filled bony channels in the temporal bone and has nerve cells that are concerned with balance and hearing. These structures are separated from the middle ear by windows with very thin membranes, the round and oval windows, that are subject to rupture by excessive Valsalva maneuver with trying to clear the ears.

Absolute Contraindications

• Inability to equalize pressure in the middle ear by auto-inflation. This may be due to a correctable problem such as polyps, nasal septal deviation or coryza in which case the diver can be reevaluated after correction of the problem.
• Perforation of the tympanic membrane. Until fully healed or successfully repaired with good Eustachian tube function, diving is contraindicated.
• Open, nonhealed perforation of the TM.
• Monomeric TM
• Tympanoplasty, other than myringoplasty (Type I)
• History of stapedectomy. * Recent studies have shown that this is not necessarily true. See this article:
  Otolaryngol Head Neck Surg 2001 Oct;125(4):356-60
  Diving after stapedectomy: clinical experience and recommendations.
  House JW, Toh EH, Perez A.
  Clinical Studies Department, House Ear Clinic and Institute, 2100 West Third
  Street, Los Angeles, CA 90057, USA.CONCLUSIONS: Stapedectomy does not appear to increase the risk of inner ear
  barotrauma in scuba and sky divers. These activities may be pursued with
  relative safety after stapes surgery, provided adequate eustachian tube
  function has been established.
• History of inner ear surgery
• Status post laryngectomy or partial laryngectomy
• History of vestibular decompression sickness
• Radical mastoidectomy (posterior) involving the external canal is disqualifying. (Closed childhood OK)
• Meniere’s disease is disqualifying
• Labyrinthitis
• Perilymphatic fistula
• Cholesteatoma is disqualifying
• Cerumen impactions -remove before allowing to dive.
• Stenosis or atresia of the ear canal-disqualifying.
• Facial paralysis secondary to barotrauma
• Tracheostomy, tracheostoma
• Incompetent larynx due to surgery (Cannot close for valsalva maneuver)
• Laryngocoele

Relative Contraindications

• Recurrent otitis externa or media
• Eustachian tube dysfunction
• History of Tympanic Membrane perforation
• Significant hearing loss in one ear
• Midface fracture
• Facial nerve paralysis
• Full mouth prosthetic devices
• Head and neck radiation
• Migraine, severe (scotomata, CNS symptoms and stroke after diving)

Physical Exam

An intact ear drum and the ability to easily autoinflate each ear by use of a gentle clearing technique. The ear drum should be visualized while this is done to ascertain movement. Tympanic perforation is a contraindication to diving, as is a thin, flaccid eardrum. A middle ear sac (cholesteatoma), stenosis or atresia of the ear canal, infection, and wax obstructions are contraindications to diving.

Laboratory Investigations

Audiometric and electronystagmographic abnormalities indicating inner ear vestibular dysfunction should disqualify for future diving.

• Nose and Paranasal Sinuses
  Patent nasal airways without acute or chronic nasal or sinus symptoms. Nasl polyps, septal deviations or anything blocking the Eustachian tubes need correction. Rhinitis medicamentosa and allergic rhinitis increase risks of barotrauma. Alpha blockers (Hytrin) causes increased mucosal congestion with increased danger of poor clearing.
• Larynx
  A person with an incompetent larynx should not dive. This is evidenced by chronic symptoms od aspiration from regurgitation and reflux. See above for contraindications.

Symptoms of Ear Dysfunction

• Ear Fullness and Pain:
  when the external ear canal is blocked with water and wax, or from increases or decreases in middle ear pressures, there will be a sensation of fullness, usually associated with some pain or discomfort. The diver feels that the ear has become blocked as there is an associated hearing loss from inability of the small bones in the ear to transmit sound. If the pressure differential gets high enough, the ear drum will rupture with extreme pain.
• Hearing Loss:

  can be conductive, that is, from physical blockage of passage of sound or transmission through the ear. It can be sensineural, or nerve hearing loss due to dysfunction in the inner ear, auditory nerve or brain. This can occur from blockage of blood vessels, trauma or bubbles in these structures, leakage of fluid, inflammation, or trauma induced degeneration as in excessive noise exposure. There can also be combinations of the above.It is widespread belief that old divers are deaf. Indeed, a number of audiometric studies have shown that a population of divers demonstrate hearing losses greater than in age-matched controls (Molvaer and Albrektsen, 1990, Susbielle and Jacquin, 1978).
  Noise induced hearing loss is the most probable cause of hearing loss in professional divers. In professional divers these hazards include the rush of gas entering a chamber during compression, the circulation of gas in diving helmets, the use of noisy underwater tools and the occasional underwater explosion. There are other causes of hearing loss in divers and, even if obvious acute causes, such as decompression sickness and inner ear barotrauma, can be excluded, repetitive subclinical episodes of these same conditions must be considered.

Evaluation of hearing Loss

• Weber test
  Tuning fork test with sound heard transmitted into the affected ear from the forehead.
• Rinne test
  Tuning fork test comparing sound from the mastoid as opposed to the air. normally and with sensineural loss, bone conduction will be heard less loudly.
• Schwabach test
  Comparison of bone conduction between the diver and the examiner, testing the diver’s mastoid tip first. If the examiner is longer, decreased nerve conduction is present.
• Tinnitus
  This is a spontaneous noise in the ear that can be from many sources; it can be a prominent symptom of middle ear disease, but is usually seen with inner ear or central auditory pathway disease.

Reference:

Scand Audiol 1999;28(2):91-6

Long-term effect of hyperbaric oxygenation treatment on
chronic distressing tinnitus.

Tan J, Tange RA, Dreschler WA, v d Kleij A, Tromp EC

Department of Otorhinolaryngology/Head and Neck Surgery, Academic Medical Center, University Hospital
of Amsterdam, The Netherlands. t.h.tan@amc.uva.nl

Tinnitus is still a phenomenon with an unknown pathophysiology with few therapeutic measures. During the last two decades, hyperbaric oxygenation therapy (HBO) has been used in the treatment of sudden deafness and chronic distressing tinnitus. In this study, we prescribed HBO to 20 patients who had had severe tinnitus for more than one year and who had already had other forms of tinnitus therapy with unsatisfactory results. Four
patients could not cope with the pressure gradient. The effect of HBO was assessed using subjective evaluation and VAS scores before and after HBO. Follow-up continued until one year after treatment. Six patients had a reduction of tinnitus and accompanying symptoms, eight patients did not notice any change and two patients experienced an adverse effect. Any outcome persisted with minor changes until one year after treatment. HBO may contribute to the treatment of severe tinnitus, but the negative effect on tinnitus should be weighed
carefully.