Surgery of violence. IV. Blast injuries of the ear.

Abstract

The shock front of a blast wave is irregular and can be deflected by obstacles in its pathway, depending on their size and position. Consequently, the injurious effects of blast tend to be capricious, and one person may be unharmed while those around him are killed or severely injured.In most explosions solid material is changed suddenly into In considering injuries from different explosions there will be differences in the size of the bombs and in the explosive material used. In any specific explosion there are factors such as the distance of the patient from the bomb, the protection afforded by walls, partitions, or other intervening obstacles, and the direction of the head at the time of the explosion. The greatest problem arises when assessing the distance of the patient from the bomb. Most people are poor at judging distances under ideal circumstances, but when asked to do so in retrospect, following a harrowing experience, they have considerable difficulty and give wildly inaccurate replies.Furthermore, in any such investigation problems arise in deciding who should be included. It is usually impossible to trace those who were nearby but uninjured, so that any survey starts off by being selective. To add to the problems one comes across those who, having heard the explosion, perhaps two blocks away, check their hearing and discover a long-standing deafness of which they had been unaware. Man, by his nature, and the Criminal Injuries (Compensation) Act, by its nature, combine to bring out the malingerer and the deaf of longstanding, who may see a silver lining in the cloud that rises from a distant explosion.It is advisable, therefore, that conclusions should be drawn from a study of a circumscribed group where the distribution of the victims can be established fairly reliably. A particularly tragic explosion fulfilled these criteria and is the subject of a report.'The "Abercorn" Explosion In the late afternoon on the first Saturday in March 1972 a small bomb of approximately 5 lb (2-3 kg) exploded in the crowded Abercorn Restaurant. Two girls were killed, four people lost both legs, one of these also losing an arm, and another girl lost one leg. Three people each lost an eye. In addition other people suffered serious injuries to the head, broken bones, burns, and lacerations.While this was a small bomb, it exploded in a confined space, and most of those in the restaurant were deafened at the time of the explosion. Some could hear nothing at all for many minutes afterwards and described seeing the lips of ambulance men and nurses moving, as in a silent film.Many of those whose ears were affected by the blast have been under review at the E.N.T. departments of the Royal Victoria and Belfast City Hospitals. Many others were traced and all were asked to indicate on a plan of the restaurant where they had been sitting at the time of the explosion. Over 80 persons who were in or just outside the building were traced and their positions determined. This confirmed the problems of establishing the distance from an ...

Blast-related ear injuries among U.S. military personnel

“…These findings are not altogether surprising when considering that rupture of the TM requires greater pressure differentials than damage to the inner ear [27]. In addition, the factors that influence the type and degree of auditory damage, such as the duration and peak pressure of the blast wave as well as the orientation of the ear [5,[14][15], might also influence the effectiveness of hearing protection. Although modern hearing protection devices appear to mitigate ear injuries involving tinnitus, they may be ill-equipped to attenuate injuries resulting from more extreme pressure differentials experienced on the battlefield, such as TM rupture.…”

“…Damage to these components of the auditory system may result in transient or permanent impairment, such as hearing loss and tinnitus (ringing in the ears) [15][16][17]. In 2010, hearing loss and tinnitus were the top two service-connected disabilities among veterans receiving compensation [18], and they are increasing at a dramatic rate [18][19][20].…”

Development of a comprehensive Blast-Related Auditory Injury Database (BRAID)

“…Damage to auditory components of the inner ear is of primary interest because it may be permanent and cause persistent symptoms of tinnitus [18][19][20] and hearing loss [6,17,[21][22][23]. Blast-related middle-ear damage has been associated with perforation of the tympanic membrane, although spontaneous recovery has been observed in the vast majority of injured patients [12,14,24]. Similarly, inner-ear temporary hearing shift caused by blast can improve slightly, but has not been reported to recover as predictably as middle-ear injuries.…”

Tympanoplasty following Blast Injury

“…[32][33][34] While most surgeons believe that a period of observation for spontaneous healing is prudent, there are arguments for both immediate and delayed tympanoplasty. [18][19][20] Advantages for immediate tympanoplasty following blast injury include the ability to perform meticulous debridement of foreign material and reapproximate trapdoor fragments of the TM, theoretically leading to more rapid healing and the prevention of future complications. 20 Kerr and Byrne concluded that surgical repair is indicated when a perforation fails to close spontaneously after 6 months.…”

“…Reported spontaneous healing rates after blast-induced TM perforation range from 38% to 82%, and no consensus exits regarding the optimal time of observation prior to repair. 6,[17][18][19] There are arguments for both immediate and delayed tympanoplasty. [18][19][20] A recent military case series demonstrated that blast-associated tympanoplasty is associated with lower success rates than non-blast-reported outcomes and showed improvements in success rates with experience.…”