Hearing in patients with blast lung

[Update: blast and explosion trauma]

In recent decades, acoustic shock and explosion traumas have increased in frequency in the general population. Beside the use of fireworks and firearms, airbag ignitions and explosions caused by terror or suicidal acts are also relevant. Depending on duration and strength of the sound pressure affecting the human ear, isolated inner ear damage or additional ear drum perforation and interruption of the middle ear ossicle chain can result. By means of otoscopy, pure tone audiometry, measurement of otoacoustic emissions, and other neurootological examinations, the severity of the trauma can be determined. With prompt and adequate therapy, permanent hearing loss can be minimized. In particular, the measurement of otoacoustic emissions allows conclusions to be made on the functionality of the outer hair cells which are damaged first in most cases. Histological investigations on noise-exposed cochleas show extensive damage to the outer hair cells in the frequency range between 1.0 and 4.0 kHz, which correlates well with audiometric measurements.

Tympanic membrane rupture in the survivors of the July 7, 2005, London bombings

OBJECTIVE

The goal of this study was to analyze the prevalence of tympanic membrane rupture in the survivors of the London bombings of July 2005 and to assess whether tympanic membrane rupture provides a useful biomarker for underlying primary blast injuries.

STUDY DESIGN

Cross-sectional study.

SUBJECTS AND METHODS

Survivors of the 4 blasts of London bombings on July 7, 2005. Data were gathered from medical records and the London's Metropolitan Police evidence documenting the injuries sustained by 143 survivors of the blasts. All patients with tympanic membrane rupture or primary blast injury were identified. Analysis was made of distance against prevalence of tympanic membrane rupture. Correlation between tympanic membrane rupture and other forms of primary blast injury was then assessed.

RESULTS

Results from the 143 survivors showed a 48% prevalence of tympanic membrane rupture across all 4 sites. Fifty-one patients had isolated tympanic membrane rupture with no other primary blast injuries. Eleven patients had tympanic membrane rupture and other primary blast injuries, but only one of these was an initially concealed injury (blast lung).

CONCLUSIONS

Tympanic membrane rupture in survivors of the London bombings on July 7, 2005, had a high prevalence affecting half of patients across a range of distances from the blasts. Tympanic membrane did not act as an effective biomarker of underlying blast lung. In a mass casualty event, patients with isolated tympanic membrane rupture with normal observations and chest radiography can be monitored for a short period and safely discharged with arrangement for ear, nose, and throat follow-up.

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.

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.