The ENT problems following the Birmingham bombings

A systematic review of otologic injuries sustained in civilian terrorist explosions

PURPOSE

Determine the prevalence of otological symptoms and tympanic membrane perforation, healing rates of tympanic membrane perforation with surgical and conservative management, and hearing function in civilian victims of terrorist explosions.

METHODS

A systematic review was conducted with searches on Medline, Embase, EMCare and CINAHL for publications between the 1st January 1945 and 26th May 2023. Studies with quantitative data addressing our aims were included. This review is registered with PROSPERO: CRD42020166768. Among 2611 studies screened, 18 studies comprising prospective and retrospective cohort studies were included.

RESULTS

The percentage of eardrums perforated in patients admitted to hospital, under ENT follow up and attending the emergency department is 69.0% (CI 55.5-80.5%), 38.7% (CI 19.0-63.0%, I2 0.715%) and 21.0% (CI 11.9-34.3%, I2 0.718%) respectively. Perforated eardrums heal spontaneously in 62.9% (CI 50.4-73.8%, I2 0.687%) of cases and in 88.8% (CI 75.9-96.3%, I2 0.500%) of cases after surgery. Common symptoms present within one month of bombings are tinnitus 84.7% (CI 70.0-92.9%, I2 0.506%), hearing loss 83.0% (CI 64.5-92.9%, I2 0.505%) and ear fullness 59.7% (CI 13.4-93.4%, I2 0.719). Symptomatic status between one and six months commonly include no symptoms 57.5% (CI 46.0-68.3%), hearing loss 35.4% (CI 21.8-51.8%, I2 0.673%) and tinnitus 15.6% (CI 4.9-40.0%, I2 0.500%). Within one month of bombings, the most common hearing abnormality is sensorineural hearing loss affecting 26.9% (CI 16.9-40.1%, I2 0.689%) of ears 43.5% (CI 33.4-54.2%, I2 0.500) of people.

CONCLUSION

Tympanic membrane perforation, subjective hearing loss, tinnitus, ear fullness and sensorineural hearing loss are common sequelae of civilian terrorist explosions.

Paper Patching Versus Watchful Waiting of Traumatic Tympanic Membrane Perforations: A Meta-Analysis

OBJECTIVES/HYPOTHESIS

The aim of the study was to investigate the healing rates, the restoration of hearing, and the time for complete healing of paper patching versus watchful waiting for traumatic tympanic membrane perforations (TTMPs).

STUDY DESIGN

Systematic review with meta analysis.

METHODS

Publications were selected by a search on "PubMed," "Embase," and "Web of Science." A meta-analysis of risk ratios for paper patching (intervention arm) and watchful waiting (control arm) was performed.

RESULTS

Five studies describing 393 TTMPs were included in the quantitative meta-analysis. TTMP healing rates ranged between 84.2% and 95.2% in the intervention arm and between 76.7% and 84.8% in the control arm. The pooled risk ratio of healed TTMPs was significantly higher in the intervention arm than in the control arm (risk ratio: 1.12, 95% confidence interval: 1.04-1.21).

CONCLUSIONS

TTMPs have high healing potential with and without intervention. The healing rate of paper patching was superior to that of watchful waiting alone.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:2091-2097, 2021.

Tympanoplasty following Blast Injury

Objectives

To assess outcomes following tympanoplasty for blast-induced tympanic membrane perforations in a military population.

Study Design

Case series with chart review.

Setting

Tertiary care medical centers.

Subjects and Methods

Military personnel (N = 254) undergoing tympanoplasty for blast-related tympanic membrane perforations sustained between April 2005 and July 2014 were identified from the Expeditionary Medical Encounter Database. Descriptive statistics were obtained regarding demographics, primary and revision surgery success rates, hearing status pre- and postsurgery, and frequency of ossicular reconstruction. Rates of successful perforation closure were assessed against perforation size and character (central vs marginal) and time to surgery. Rates and types of complications were additionally explored.

Results

There were a total of 352 operations among 254 subjects, with an 82.1% rate of successful closure following primary surgery. For successful primary tympanoplasty, the mean improvement in pure tone average was 11.7 ± 12.1 dB. Ossiculoplasty was performed in 9.1% (32 of 352) of cases. There was no significant relationship between successful perforation closure and perforation size, perforation character, or time between injury and surgery. Cholesteatoma complicated 4.3% (15 of 352) of cases. A significant relationship was identified between risk of cholesteatoma development and increasing perforation size and marginal perforations.

Conclusion

Tympanoplasty success rates for blast-induced tympanic membrane perforations are lower than for other common injury mechanisms. Due to appreciable rates of postoperative cholesteatoma development, close clinical surveillance is recommended.

Direct application of bFGF without edge trimming on human subacute tympanic membrane perforation

OBJECTIVE

To investigate the feasibility of direct application of basic fibroblast growth factor (bFGF) without edge trimming on human subacute traumatic tympanic membrane perforation (TMP).

METHODS

A total of 29 patients with traumatic TMPs beyond 1 month after trauma were enrolled. Patients were placed into two groups: an observation group (n=17) and a bFGF-treated group (n=12). The bFGF-treated group was treated by direct application of bFGF, in which the margin of the perforation was not trimmed. All patients were followed at least once per week until the perforation was completely closed or for up to 6 months. The closure rate and closure time were estimated.

RESULTS

At 6 months, 11/12 (91.7%) perforations achieved complete closure after bFGF treatment. The mean closure time was 18.1 ± 11.4 days (range=3-65 days). Purulent otorrhea was found after treatment in five patients, but resolved after oral amoxicillin and ofloxacin ear drops. Of these five patients, four achieved complete closure. However, only 9/17 (52.9%) perforations achieved complete spontaneous closure in the observation group. FGF-treated groups had significantly improved closure rates compared to the observation group (91.7% vs. 52.9%, respectively, P=0.03).

CONCLUSIONS

Although the margin of the perforation was not trimmed, direct application of bFGF on human subacute TMP was feasible, and it could significantly improve the closure rate of the subacute TMPs. The technique was simple and convenient. Thus, direct application of bFGF should be recommended pre-myringoplasty.

Earache

Earache, a common emergency department presentation, may be caused by a variety of conditions, some distant from the ear. This article discusses the diagnosis and treatment of acute otitis media, otitis media with effusion, otitis externa, otitis media with ruptured tympanic membrane or tympanostomy tubes, malignant otitis externa, mastoiditis and petrositis, traumatic ruptured tympanic membrane, cerumen impactions, and foreign bodies in the ears.

Mechanisms and treatment of blast induced hearing loss

The main objective of this study is to provide an overview of the basic mechanisms of blast induced hearing loss and review pharmacological treatments or interventions that can reduce or inhibit blast induced hearing loss. The mechanisms of blast induced hearing loss have been studied in experimental animal models mimicking features of damage or injury seen in human. Blast induced hearing loss is characterized by perforation and rupture of the tympanic membrane, ossicular damage, basilar membrane damage, inner and outer hair cell loss, rupture of round window, changes in chemical components of cochlear fluid, vasospasm, ischemia, oxidative stress, excitotoxicity, hematoma, and hemorrhage in both animals and humans. These histopathological consequences of blast exposure can induce hearing loss, tinnitus, dizziness, and headache. The pharmacological approaches to block or inhibit some of the auditory pathological consequences caused by blast exposure have been developed with antioxidant drugs such as 2,4-disulfonyl α-phenyl tertiary butyl nitrone (HXY-059, now called HPN-07) and N-acetylcysteine (NAC). A combination of antioxidant drugs (HPN-07 and NAC) was administered to reduce blast induced cochlear damage and hearing loss. The combination of the antioxidant drugs can prevent or treat blast induced hearing loss by reducing damage to the mechanical and neural component of the auditory system. Although information of the underlying mechanisms and treatment of blast induced hearing loss are provided, further and deep research should be achieved due to the limited and controversial knowledge.

Noise-Induced Hearing Injury and Comorbidities Among Postdeployment U.S. Army Soldiers: April 2003–June 2009

Purpose

To evaluate noise-induced hearing injury (NIHI) and blast-related comorbidities among U.S. Army soldiers in an effort to understand the morbidity burden and future health service requirements for wounded war fighters returning from the Central Command Area of Responsibility, predominantly from Iraq and Afghanistan deployments.

Method

Inpatient and outpatient records with diagnosed NIHI or blast-related comorbidities (e.g., significant threshold shift [STS], noise-induced hearing loss, tinnitus, sensorineural hearing loss, eardrum perforations, mild traumatic brain injury, and posttraumatic stress disorder) were extracted for active duty soldiers returning from combat deployments. Records were limited to those within 6 months of the soldier’s return date from April 2003 through June 2009. To account for changes in STS coding practice, STS rates observed after October 1, 2006, were used to extrapolate prior probable postdeployment STS.

Results

Statistically significant increases were observed for tinnitus, dizziness, eardrum perforations, and speech-language disorders. The combination of observed and extrapolated STS yielded a conservative estimate of 27,427 cases.

Conclusions

Estimates can be used to forecast resource requirements for hearing services among veterans. This article could serve as a guide for resourcing and innovating prevention measures and treatment in this population. Data provided may also serve as a baseline for evaluating prevention measures.

Ear injuries sustained by British service personnel subjected to blast trauma

Objectives:

To describe the pattern of ear injuries sustained by all British servicemen serving in Iraq and Afghanistan between 2006 and 2009; to identify all servicemen evacuated to the Royal Centre for Defence Medicine following blast injury; to ascertain how many underwent otological assessment; and to calculate the incidence of hearing loss.

Design and setting:

A retrospective analysis of data obtained from the Joint Theatre Trauma Registry and the Defence Analytical and Statistics Agency, together with audiometry records from the University Hospitals Birmingham National Health Service Trust.

Results:

Ear damage was present in 5 per cent of all British servicemen sustaining battle injuries. Tympanic membrane rupture occurred in 8 per cent of personnel evacuated with blast injuries. In 2006, 1 per cent of servicemen sustaining blast injury underwent audiography; this figure rose to 13 per cent in 2009. Fifty-three per cent of these audiograms were abnormal.

Conclusion:

The incidence of tympanic membrane rupture was higher than that found in previous conflicts. Otological assessment prior to and following military deployment is required to determine the incidence of ear injury amongst British servicemen following blast trauma.

Otologic considerations of blast injury

The ear by design is exquisitely sensitive to barotrauma. As a result, it is typically the first organ affected in primary blast injury. The most common symptoms encountered include hearing loss, ringing, and drainage. In severe cases, the highest priority is appropriately directed toward diagnosis and treatment of life-threatening injuries; however, injury to the ear is missed frequently. With simple screening procedures, limited management, and appropriate otolaryngologic referral, acute and long-term morbidity can be averted for both critical and noncritical patients. The article provides an overview of blast mechanics and pathophysiology. It details various blast-related injuries to the external, middle, and inner ear. Standard of care assessment and management strategies are presented for acute and late otologic sequelae of the blast-injured patient.

Tympanic membrane perforation and hearing loss from blast overpressure in Operation Enduring Freedom and Operation Iraqi Freedom wounded

BACKGROUND

Tympanic membrane perforation is the most common primary blast injury in the current conflicts and occurs in approximately one tenth of service members wounded by combat explosions. We wanted to determine the severity of perforation and its effect on hearing and combat readiness.

METHODS

This analysis is a retrospective study of US service members injured in combat explosions in Afghanistan or Iraq and treated at our institution between March 2003 and July 2006. Data captured included location and grade of perforation, symptoms, healing rates, audiogram results, need for hearing aids, and loss of eligibility for military service.

RESULTS

Of 436 explosion-wounded patients admitted to our facility, 65 (15%) patients had tympanic membrane perforation diagnosed by the otolaryngology service. A total of 97 tympanic membrane perforations occurred among 65 patients. The average surface area involved was 41% +/- 32% (right) and 35% +/- 34% (left). More than one third of perforations were grade 4. The most common locations were central and anterior-inferior. Most (83%) patients reported symptoms, most commonly diminished hearing (77%) and tinnitus (50%). Outcome data were available for 77% of perforations. Spontaneous healing occurred in 48%. The remainder (52%) had surgical intervention. The most common audiogram abnormality was mild high frequency hearing loss. Ultimately, three patients (5%) required hearing aids and one discharge from military service.

CONCLUSIONS

Tympanic membrane perforation occurs in 16% of explosion-injured patients. Most patients are symptomatic and many have large perforations requiring operative intervention. Long-term hearing loss is uncommon but does impact ability to continue military service.

Otorrinolaringología

The terrorist attack on 11 March caused a high percentage of patients with ear injuries. Shock waves provoke alterations to the external ear as well as to the middle and inner ear. The most frequent lesion is tympanic membrane perforation. Initial evaluation with otoscopy, acoumetry, tonal audiometry and vestibular examination was performed and was repeated after 2 and 3 months. In most patients there was a correlation between the grade of middle ear lesion and auditory damage. In most patients with tympanic rupture, the perforation was total or subtotal. Spontaneous closure can occur in some patients but is usually related to the size of the initial lesion. Thus in tympanic perforations of more than 50%, spontaneous closure is unlikely.

Otologic consequences of blast exposure: a Finnish case study of a shopping mall bomb explosion

OBJECTIVE

On 11 October, 2002, in the Myyrmanni shopping mall, Vantaa city, Finland, an explosion by a suicide bomber killed 7 people and injured at least 160,44 of whom had ear trauma. We investigated the acute and subacute otologic consequences of the explosion.

MATERIAL AND METHODS

Otologic examination of the 29 patients treated for ear trauma at the ENT clinic of the University Hospital of Helsinki was performed during the first month after the explosion, and a questionnaire was completed regarding subjective aural symptoms. Symptoms occurring directly after the explosion and for up to 1 month afterwards were assessed.

RESULTS

Of the 29 patients, 66% had tinnitus as the initial symptom, 55% hearing loss, 41% pain in the ears and 28% sound distortion. Tinnitus and hearing loss in combination were experienced by 12 patients (41%). Eight patients who had been situated<10 m from the center of the explosion had a rupture of the tympanic membrane. This supported the initial evaluation by the authorities that the bomb had consisted of approximately 3 kg ammonium nitrate, equivalent to approximately 0.5 kg of trinitrotoluene. It was estimated that some kind of ear injury was likely for individuals situated<70 m from the center of the explosion.

CONCLUSIONS

People often think that tinnitus and hearing impairment are naturally occurring phenomena after blast exposure, and if their symptoms resolve they do not seek medical advice. However, some of them may have substantial hearing impairment, particularly at high frequencies. Otologic consultation, or at least an audiometric screening test to exclude hearing impairment, should be performed regardless of symptoms, on the basis of exposure data only. Some symptoms, such as tinnitus and hearing loss, may be permanent consequences of a blast injury and their effect on quality of life may be substantial.

Otological trauma resulting from the Soho Nail Bomb in London, April 1999

We report the otological effects of the April 1999 Soho Nail Bomb on 17 patients. Twenty-one (62%) tympanic membranes were perforated (pars tensa only); 78% closed spontaneously within 6 months. The mean size of the perforation in the tympanic membrane nearer to the blast was significantly larger than the opposite side [33% +/- 8.3 (mean +/- SD) and 13% +/- 4.1 respectively; P = 0.02]. All patients reported hearing losses that were mixed conductive and sensorineural but mainly high-frequency sensorineural (4, 6 and 8 kHz, pure tone average 42.3 dB +/- 20.5). The sensorineural hearing loss correlated inversely with the distance from the explosion but not with the size of perforation. There was no significant difference in the hearing loss between the ear facing the blast and the opposite ear. Fifteen patients (88%) had temporary tinnitus. No patient complained of any vestibular symptoms. The otological effects of a nail bomb in an enclosed space have not been previously reported. Furthermore, an inverse correlation between hearing loss and distance from the explosion and a significant difference in perforation size facing the blast, compared with the opposite side, are also presented for the first time. The high spontaneous closure rate of perforations and minimal ongoing disability from sensorineural losses favour conservative management in most cases.

Explosions and blast injuries

Powerful explosions have the potential to inflict many different types of injuries on victims, some of which may be initially occult. Flying debris and high winds commonly cause conventional blunt and penetrating trauma. Injuries caused by blast pressures alone result from complex interactions on living tissues. Interfaces between tissues of different densities or those between tissues and trapped air result in unique patterns of organ damage. These challenge out-of-hospital personnel, emergency physicians, and trauma surgeons to specifically seek evidence of these internal injuries in individuals with multiple trauma, adjust management considerations to avoid exacerbation of life-threatening problems caused by the blast wave itself, and ensure appropriate disposition of these patients in possible mass-casualty situations. Knowledge of the potential mechanisms of injury, early signs and symptoms, and natural courses of these problems will greatly aid the management of blast-injured patients.

Otologic injuries caused by airbag deployment

Airbags are clearly successful at mitigating injury severity during motor vehicle accidents. Deployment unfortunately has introduced new injury-causing mechanisms. A retrospective review of 20 patients who sustained otologic injuries resulting from airbag inflation was conducted. The most common symptoms were hearing loss in 17 (85%) and tinnitus in 17 (85%). Objective hearing loss was documented in 21 of 24 (88%) subjectively affected ears; this included unilateral and bilateral sensorineural, unilateral conductive, and mixed hearing losses. Ten patients (50%) had dysequilibrium. Four subjects (20%) had a tympanic membrane perforation; each required surgical closure. Ear orientation toward the airbag was found to be associated with hearing loss (P = 0.027), aural fullness (P = 0.039), and tympanic membrane perforation (P = 0.0004). A wide variety of airbag-induced otologic injuries occur and may have long-term sequelae. It is important for health care personnel to be aware of these potential problems.

Multifocal cholesteatoma of the external auditory canal following blast injury

Posttraumatic cholesteatoma of the external auditory canal is a rare condition that may present years after the original injury. A unique case of multifocal cholesteatoma of the external auditory canal following blast injury is presented and discussed.

Automobile airbag impulse noise: otologic symptoms in six patients

Automobile airbag safety systems have successfully reduced the number of occupant injuries from motor vehicle accidents. Unfortunately, airbags are also associated with some inherent risk, including a high-amplitude, short-duration noise from airbag deployment. A review of the available research in the automobile industry indicates that the peak amplitude of this noise may exceed 170 dB sound pressure level. Despite the increasingly wide application of airbags in automobiles, there have been no previous reports of airbag-related otologic injuries. We have encountered six patients with otologic symptoms that appear to be related to airbag impulse noise. Five of these patients have documented hearing loss, one patient reported persistent tinnitus, and two patients have significant dysequilibrium. Although permanent hearing loss from airbag noise appears to be rare, temporary threshold shifts are probably much more common. It is important, therefore, that the clinician be aware of the noise associated with airbag inflation and the possibility of acoustic trauma from these safety devices.

Patterns of hearing loss in non-explosive blast injury of the ear

A prospective study of hearing loss in 120 cases with non-explosive blast injury of the ear, gathered over a six-year period, is presented. Thirty-three (27.5 per cent) patients had normal hearing, 57 (47.5 per cent) conductive hearing loss, 29 (24.2 per cent) mixed loss and one (0.8 per cent) had pure sensorineural loss. The severity of conductive hearing loss correlated with the size of the eardrum perforation; only a marginal difference was found between water and air pressure injuries, with respect to this type of hearing loss. Of all locations, perforations involving the posterior-inferior quadrant of the eardrum were associated with the largest air-bone gap. Audiometric assessment revealed that none of the patients suffered ossicular chain damage. Three patterns of sensorineural hearing loss were identified: a dip at a single frequency, two separate dips, and abnormality of bone conduction in several adjacent high frequencies. Involvement of several frequencies was associated with a more severe hearing loss than a dip in a single frequency. Healing of the perforation was always accompanied by closure of the air-bone gap, while the recovery of the sensorineural hearing loss was less favourable.

Extended high-frequency audiometry in traumatic tympanic membrane perforations

Air- and bone-conduction audiometry in the frequency ranges 0.125-18 kHz and 0.25-16 kHz respectively were performed in 38 patients with unilateral traumatic tympanic membrane perforation. Sensorineural threshold elevation was found in 16 ears. In nine of these this was permanent and in four restricted to the frequency range > 8 kHz. Both sensorineural threshold elevation and tinnitus (n = 16) diminished with time. A temporary, mean 5 dB, bone-conduction threshold elevation > or = 8 kHz was seen in 26 ears before spontaneous tympanic membrane closure. Closure resulted in a 7-20 dB improvement of air-conduction thresholds in the 0.125-18 kHz range, somewhat less in the upper than in the lower frequencies. A 3 dB mean final conductive hearing loss > 8 kHz was found in these 26 ears approximately 5 months after injury, probably due to scars in the pars tensa at the site of the former perforations. Thirty-seven of 38 perforations had healed at final follow-up examination.

Management of unique clinical entities in disaster medicine

This article discusses the management of clinical problems encountered particularly in disasters. These include the principles of multiple-casualty triage, and field and hospital management of blast injury, crush syndrome, compartment syndrome, particulate inhalation, and traumatic asphyxiation. The indications for extraordinary measures, such as field amputation, are detailed. A brief review of the causes and epidemiology of these entities is provided, with emphasis on the clinical management in the disaster setting.

Blast injury of the ear: an overview and guide to management

Blast injury is uncommon in many parts of the world but sporadic cases occur. The ear is particularly susceptible to damage and easily forgotten in patients with multiple injuries. The aim of this review article is to draw together the more important aspects of blast ear injury for those who are unfamiliar with it and to serve as a reminder of the problems to others. It covers the interactions of blast waves with the ear giving a summary of the mechanisms and types of injury. The management of blast-related injuries is discussed.

Hearing loss in the 4-8 kHz range following tympanic membrane perforation from minor trauma

This study looked at the incidence of sensorineural hearing loss in the 4-8 kHz range in patients with unilateral tympanic membrane perforations from minor trauma who presented to the department in the past year. Eleven patients conformed to our inclusion criteria, one was lost to follow-up. Perforation was present in all patients in the pars tensa and no treatment was required in nine patients. The mean sensorineural hearing loss at 4,6 and 8 kHz was 28.2 dB on initial examination and 14.6 dB by Day 30. All 11 patients had normal hearing in the contra-lateral ear (mean 13.5 dB). In this group of patients with a tympanic membrane perforation from minor trauma the conductive hearing loss was accompanied by a significant (P = 0.001) but reversible high frequency sensorineural deafness.

Blast injury of the auditory system: a review of the mechanisms and pathology

Blast injury of the auditory system is uncommon and our knowledge incomplete. This article reviews the literature to date giving an account of the interactions of blast waves with the ear, the mechanisms of injury, the pathology, the clinical features, and an outline of management principles.

Retropharyngeal myxoma: a case report

Myxomas are rare tumours which may occur in the head and neck region. About 60 cases have been reported in the literature so far. We describe a retropharyngeal myxoma in this paper.

Non-explosive blast injury of the ear

Non-explosive blast injury of the ear refers to the otological trauma caused by a blow to the ear that seals the external auditory meatus. It results in a sudden increase of air pressure within the ear canal that strikes the tympanic membrane. The present study portrays the various aspects of middle and inner ear damage in 91 patients resulting from an assault we entitled a 'non-explosive blast injury' to the ear. Sixty cases were caused by a slap or a fist, 13 patients suffered sport accidents, mostly in ball games, and 18 patients were injured during swimming and water sports activities. The common symptoms were hearing loss, earache, tinnitus, vertigo and otorrhoea. All 91 patients presented with acute perforations of their eardrums. The mean conductive hearing loss was 11.2 dB. A high tone sensorineural hearing loss was detected in only 20 per cent of the patients. A spontaneous closure of the perforation with a conservative management approach was observed in 94.8 per cent of the patients. Healing of the perforation was always associated with closure of the air-bone gap, while the results of the sensorineural hearing loss recovery were less favourable.

Tympanic membrane perforation in survivors of a SCUD missile explosion

On February 25, 1990, an Iraqi SCUD missile exploded inside a building housing United States military personnel in Dhahran, Kingdom of Saudi Arabia. One hundred seventy-two individuals who were near the impact site at the time of the blast were interviewed and examined to determine blast injury to the ear. Tympanic membrane (TM) perforation was used as the clinical marker for aural blast injury. Thirty-four personnel had unilateral TM perforation and 28 had bilateral TM perforation. Eighty-six sustained sufficient injury to be hospitalized. Fifty-nine of hospitalized personnel (70%) had TM perforation. Of a total of 90 TM perforations, 39% were estimated to be 25% or less of the tympanic membrane surface area, 36% were 26% to 50%, 16% were 51% to 75%, and 10% were greater than 75%. Morphology of the perforations and estimated proximity to the blast were documented. Personnel distant from the blast, in open doorways or wearing headphones, had relative protection from TM perforation. Historic nuclear blast data were used to estimate the SCUD blast waveform based on measurements of the SCUD impact crater. A mathematical model based on the estimated waveform was validated against the actual field data by comparing the proximity and incidence of TM perforations in the SCUD missile explosion.

Errors in the assessment of tympanic membrane perforations

It is commonly stated that operative closure of large perforations of the tympanic membrane is less successful than closure of small perforations. Few authors mention the exact size of the perforations studied, and fewer still give their method of measuring perforations. We describe a photographic method of assessing the size of perforations relative to the total drumhead, measuring them with a computerized digitizing pad. Thirteen temporal bones were selected at random. Perforations of different sizes, shapes and at different sites were fashioned in the tympanic membranes. These were assessed by clinicians of all grades, who were asked to draw the perforations and give estimates of the perforation size as a percentage of the total drumhead. Visual estimates and drawings were compared with a photographic objective method. Gross errors (some in excess of 100%) were apparent in both estimates and drawings. There was a highly significant statistical difference between the objective method and visual estimates and drawings (P < 0.001). Greater clinical experience was not correlated with better performance in estimating the size of perforations.

Spontaneous healing of traumatic tympanic membrane perforations in man: a century of experience

Widespread controversy exists concerning the treatment of traumatic tympanic membrane perforations. To elucidate the issue, a reference value for the rate of spontaneous tympanic membrane closure in man, to which the healing rates following different techniques of early surgical repair should be compared, was established on the basis of a review of more than 500 texts covering a century's literature on the traumatically perforated tympanic membrane. The spontaneous healing rate appeared to be close to 80 (78.7 per cent) in 760 evaluable cases of traumatic tympanic membrane perforations of all sorts diagnosed within 14 days post injury. A relative, causal-related variation of spontaneous healing could be demonstrated, and a pathogenetic classification of direct traumatic tympanic membrane perforations into ruptures induced by air-pressure changes, heat or corrosives, solids, and water pressures, is of proved clinical value and may have medico-legal validity. There is an obvious need for clinically controlled studies on the spontaneous healing of all kinds of traumatic perforations of the tympanic membrane in humans, and important elements in the design of future studies are advocated.

Blast injuries of the ear as a result of the Peterborough lorry explosion: 22 March 1989

The incidence of blast trauma to the ears in significant numbers is relatively rare in peace time. This paper outlines the results and management of twenty patients injured as a result of the outside explosion of 800 kg of high explosives in Peterborough on 22 March 1989.

An evaluation of myringoplasty in war injured people

Perforation of the tympanic membrane is a common war injury, especially after explosions. Such perforations will normally heal spontaneously under favourable conditions. A small number in whom the defect persists will benefit from closure by myringoplasty. Thirty-four such cases underwent operative repair and were compared with an equal number due to other causes.

Treatment of blast injury to the ear

Blast injury to the ear has long been acknowledged as potentially incapacitating. This paper discusses the scope of these injuries in terms of the anatomic and physiologic consequences. Management of both acute and chronic injuries is discussed, with specific regard to the deficits in a patient's functional ability once blast injury has occurred.

Blast injury of the ear: historical perspective

Blast injury of the ear is rarely encountered by the practicing otolaryngologist. The recent world literature on this entity is reviewed. Symptoms, patterns of injury, and clinical course are highlighted and should form the basis of management under acute and chronic circumstances.

Primary blast injuries

Injury from explosion may be due to the direct cussive effect of the blast wave (primary), being struck by material propelled by the blast (secondary), to whole-body displacement and impact (tertiary), or to miscellaneous effects from burns, toxic acids, and so on. Severe primary blast injury is most likely to be seen in military operations but can occur in civilian industrial accidents or terrorist actions. Damage is seen almost exclusively in air-containing organs--the lungs, the gastrointestinal tract, and the auditory system. Pulmonary injury is characterized by pneumothorax, parenchymal hemorrhage, and alveolar rupture. The last is responsible for the arterial air embolism that is the principle cause of early mortality. Treatment for blast injury is similar to that for blunt trauma. The sequalae of air embolization to the cerebral or coronary circulation may be altered by immediate hyperbaric therapy. Use of positive pressure ventilatory systems should be closely monitored as they may increase the risk of air embolism in pneumothorax. Morbidity and mortality may be increased by strenuous exertion after injury and by the wearing of a cloth ballistic vest at the time of the blast.

Auditory brainstem evoked potentials in blast injury

Blast injury typically consists of a mixed conductive and sensorineural hearing loss. The sensorineural component includes temporary as well as permanent threshold elevations. Auditory brainstem evoked potentials (ABEP) are sensitive to functional changes in various levels along the auditory pathway. ABEP were recorded from 37 survivors of blasts and latency measures were correlated with clinical findings. Prolongation of peak latencies was correlated with the conductive component of blast-induced hearing loss, as well as with the TTS component of the sensorineural impairment. No central effects of blast on the auditory system were detected. In addition to their objectivity, ABEP hold the promise of differentiating between the permanent and temporary effects of blast on hearing.