Barotrauma of the Middle Ear, Sinuses, and Lung

Basics

Description

  • Barotrauma is tissue damage resulting from the direct effects of pressure changes or imbalances between ambient pressure and pressure within an enclosed body cavity.
  • Body cavities at greatest risk for barotrauma
    • Middle ear (otic barotrauma)
    • Paranasal sinuses (sinus barotrauma)
    • Lungs (pulmonary barotrauma)
  • Dental barotrauma
    • Dental work can create small pockets of air, which can damage teeth in scuba divers or aviators during ambient pressure changes.
  • Synonym(s): dysbarism; aerotitis; otitic barotrauma; middle ear barotrauma; barotitis; barosinusitis
ALERT
  • Dizziness and sensorineural hearing loss warrant immediate ENT referral for inner ear involvement.
  • Valsalva maneuver can spread nasopharyngeal infection into the middle ear.

Epidemiology

Incidence

  • Pulmonary barotrauma is second only to drowning as a leading cause of death among divers.
  • Pulmonary barotrauma affects 2–3% of mechanically ventilated patients (1).
  • Otic barotrauma is common in air travel, particularly among flight personnel, affecting 8–17% of aircrew (2,3).

Pediatric Considerations

  • Children have difficulty opening the eustachian tube and commonly develop upper respiratory infections. This combination results in higher risk for otic and sinus barotraumas with smaller pressure changes than adults.
  • Mechanical ventilation of neonates is associated with barotrauma and contributes to bronchopulmonary dysplasia.

Pregnancy Considerations
Increased nasal congestion in pregnancy increases the risk of barotitis media (barotrauma of the middle ear).

Etiology and Pathophysiology

  • Boyle law (PV = k), relating volume and pressure of gases, applies to all forms of barotrauma. When gas is trapped in a confined space, such as the middle ear, paranasal sinus, or lungs, a sudden decrease in ambient pressure causes expansion of the gas within the cavity.
  • Pulmonary barotrauma
    • Iatrogenic complication of mechanical ventilation or hyperbaric oxygen treatment
    • When the transalveolar pressure disrupts the structural integrity of the alveolus, the alveolar wall can rupture, leading to interstitial emphysema, pneumothorax, or pneumomediastinum.
    • Complication of rapid ascent scuba diving with a closed glottis
  • Otic and sinus barotrauma:
    • Sudden pressure differentials between middle and inner ear may lead to rupture of the round or oval window. This can create a labyrinthine fistula, which consequently can allow leakage of perilymph.
    • Damage to the inner ear may be permanent.
    • Otalgia (earache) and hearing loss occur as a result of stretching and deformation of the tympanic membrane (TM).
    • Associated with rapid or extreme changes in ambient pressure: air travel, mountain climbing, scuba diving
      • Nasal congestion or eustachian tube dysfunction increases risk of damage.
      • Failure of eustachian tube to equilibrate pressure may distort the tympanic membrane, causing discomfort or rupture.
      • Rupture of round or oval membrane may cause inner ear barotrauma, vertigo, sensorineural hearing loss.

Risk Factors

  • Pulmonary
    • Iatrogenic:
      • Mechanical ventilation, especially in the presence of asthma, chronic interstitial lung disease, acute respiratory distress syndrome
      • Hyperbaric oxygen therapy
    • Scuba diving or other underwater activities
    • Air travel with preexisting pulmonary pathology
  • Otic or sinus
    • Participation in high-risk activities without adequate pressure equilibration
      • Scuba diving, especially with rapid ascent or breath holding
      • Airplane flight
      • Skydiving
      • High-altitude travel
      • High-impact sports: boxing, soccer, waterskiing
    • Upper respiratory infections
    • Nasal congestion or allergic rhinitis
    • Eustachian tube dysfunction
    • Blast exposure
    • Hyperbaric oxygen treatment
    • Pregnancy (associated nasal congestion)
    • Anatomic obstruction
      • Deviated nasal septum
      • Nasal polyps
      • Swollen/enlarged adenoids
      • Congenital anomalies, including cleft palate
    • Previous history of ear trauma, ENT disorders, or ear pain after air travel

General Prevention

  • Prevention/avoidance is best: Avoid flying or diving when risk factors are present.
  • Pulmonary barotrauma
    • Cautious use of mechanical ventilation, employing lung-protective vent settings (lower end-inspiratory airway pressures, lower tidal volumes of 6 mL/kg, higher positive end-expiratory pressures of 6 to 12 cm H2O) (1)[A]
    • Lung-protective settings during mechanical ventilation (1)[A]
      • Acute lung injury: NNT = 16
      • Lung injury: NNT = 11
    • Cautious use of hyperbaric oxygen therapy
    • Avoid breath holding during ascent while scuba diving.
  • Otic barotrauma
    • 120 mg PO pseudoephedrine prior to flying in adults (4)[A]
    • 1 mg/kg pseudoephedrine in children is not effective (4)[B].
    • Avoid altitude changes or scuba diving with eustachian tube dysfunction.
    • Treat upper respiratory congestion.
    • Avoid head down position on ascent/decent when scuba diving (5)[B].
  • Autoinflate the eustachian tube during pressure changes (3)[B].
    • Valsalva during ascent and descent in air travel
    • Infants: breastfeeding, pacifier use, or bottle feed
    • ≥4 years: chewing gum
    • ≥8 years: blowing up a balloon
    • Adults: chewing gum, swallowing, or yawning
  • Pressure-equalizing earplugs are not recommended in air travel and do not prevent ear barotrauma (4)[B].

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