Background

• Most common inj seen
• May indicate possibility of pulmonary injury
  • Indicates high pressure wave struck casualty
  • Suggest CXR, observation , possible CT of chest
  • Actual correlation now questioned

Pathophysiology

• Damage to middle & inner ear
  • Isolated tympanic membrane rupture most common
  • Hemotympanum without rupture
  • Ossicle fracture / dislocation
• Due to overpressure from blast wave
• Sensorineural hearing loss can occur
  • Infection
  • Ototoxic ear drops

Diagnostics

• Symptoms
  • Hearing loss, tinnitus
  • Ear pain, bloody fluid
• Physical Exam
  • Routine otoscopy
  • Otomicroscopy for small perforations
  • See also TM injury staging
• Diagnostic Testing
  • Middle-ear impedence testing
  • Audiometry

Treatment

• Most perforations heal spontaneously
• Tympanic rupture: remove debris, irrigate canal
  • See also treatment by severity
• Perform primary closure if >1/3 of membrane damaged
  • Outpatient treatments
    • Cautery paper patch
    • Fat plug tympanoplasty
    • Irritant oil
  • Operating room techniques
    • Tympanoplasty >90% effective
• No specific therapy for sensorineural acoustic trauma