Ears

The ear is designed to efficiently transmit pressure waves and is the organ most likely to sustain a primary blast injury.

It is essential therefore that every patient involved in a blast, when appropriate and taking into consideration other injuries, be assessed otologically in the course of their hospital assessment [1].

Typical injuries

Many victims will suffer a short-lived but profound period of sensorineural deafness and tinnitus that resolves within hours [1].

Persisting deafness and tinnitus results from tympanic membrane rupture that may occur at pressures as low as 5 psi [3] and this usually occurs at the pars tensa [4].

Although intact tympanic membranes were once relied upon as a marker of absence of exposure to significant over-pressures, significant primary blast injuries may occur in its absence [1]. In one study, 36.7% of patients with blast lung injury had intact tympanic membranes.

Less typical injuries

Disruption of the ossicular chain, most often at the incudomalleolar joint [17], and distortion or destruction of the oval or round windows, are rarer primary blast injuries but cause significant morbidity.

Vertigo is relatively rare following blast injury and, although perilymph fistulae should be excluded in patients with unresolving vertigo at two weeks, it is usually attributable to concussional syndromes following head injury [6].

Treatment

In the ED, little treatment is required for tympanic membrane rupture [11].

ED medics must ensure that otological examination is performed and recorded [12] and all patients, whether conscious of deafness or not, should undergo audiometric follow-up [1,11].

Simple advice can be given to patients regarding:

  • The avoidance of submersion in water
  • Probing the ear canal
  • Seeking early antibiotics in the event of infection

Learning Bite

Intact tympanic membranes do not exclude primary blast injury to other organs.