Middle Ear Barotrauma

Middle ear barotrauma is injury to the tympanic membrane and middle ear from failure to equalise pressure on descent in diving, flying or hyperbaric treatment. It is the commonest diving injury.

Epidemiology. Affects a large share of divers at some point and is more frequent in novices. Descent is more dangerous than ascent: the eustachian tube opens poorly against rising outside pressure.

Risk factors. Upper respiratory infection, allergic rhinitis, smoking, anatomical narrowing, rapid descent and decongestant rebound.

Grading. Grade 0: symptoms only. Grade 1: redness of the eardrum. Grade 2: slight haemorrhage in the drum. Grade 3: gross haemorrhage in the drum. Grade 4: middle ear haemorrhage with bulging drum. Grade 5: perforation.

Inner ear injury. Forceful Valsalva can rupture the round or oval window and cause inner ear barotrauma.

Pathophysiology.

Rising ambient pressure pushes the drum inward while a closed eustachian tube keeps middle ear pressure lower. This stretches and injures mucosa and drum, with transudate and bleeding into the middle ear.

Overpressure on ascent or forceful Valsalva raises inner ear pressure and can tear the round window membrane.

• Ear fullness or pain on descent, with muffled hearing.
• Blood stained nasal discharge or bleeding, and cold sensation with vertigo when the drum perforates.
• Inner ear injury: sensorineural hearing loss, tinnitus, vertigo and nausea.

Red flags.

• Hearing loss with vertigo, tinnitus or vomiting (inner ear barotrauma or window rupture).
• Facial weakness, severe pain or discharge that persists.

• Dive and flight history, equalising technique and nasal symptoms.
• Otoscopy for drum colour, bleeding, fluid and perforation.
• Audiometry with tuning fork tests; tympanometry; formal audiometry for any hearing symptom.
• Urgent ENT assessment for suspected inner ear injury; CT temporal bone if a window fistula is suspected.

Differential diagnosis. Otitis media and externa, inner ear decompression sickness, alternobaric vertigo, eustachian tube dysfunction, cholesteatoma, trauma.

• Stop diving, flying and strenuous Valsalva until healed. Gentle autoinflation only.
• Analgesia: paracetamol 1 g orally every 6 hours as needed, maximum 4 g in 24 hours (3 g if under 50 kg, chronic alcohol excess or liver disease). Reduce dose in hepatic impairment; extend dosing interval when eGFR is under 30.
• Allergic or nasal congestion: mometasone nasal spray 50 micrograms/spray, 2 sprays into each nostril once daily for 2 to 4 weeks. Maximum 200 micrograms daily. Monitor for nosebleeds and local irritation. Avoid in untreated nasal infection; no renal adjustment.
• Short term nasal decongestant: oxymetazoline 0.05% spray, 2 sprays into each nostril twice daily for no more than 3 days. Maximum 3 days, because of rebound congestion. Monitor blood pressure; avoid in uncontrolled hypertension and with monoamine oxidase inhibitors. Not for use before diving.
• Perforation: keep the ear dry, no water or syringing, and avoid ear drops unless infected. With infection, ciprofloxacin 0.3% ear drops, 4 drops into the ear twice daily for 7 days. Monitor for resolution. Quinolone drops are safe in perforation.
• Perforation persisting over 3 months, or ossicular injury: surgical repair by ENT.
• Inner ear barotrauma or fistula: bed rest with head up, avoid straining, urgent ENT, and surgical exploration if hearing or vertigo worsens. Corticosteroids have unproven benefit.
• Return to diving: only after the drum is intact, hearing is normal and the diver can equalise freely, usually 2 to 4 weeks for mild injury and over 6 weeks for perforation.

Monitoring. Otoscopy and audiometry at 2 weeks and at 6 weeks; repeat until healed.

Referral and escalation. ENT for perforation, hearing loss, vertigo or persistent symptoms; diving physician for fitness assessment.