Blast deafness
Introduction
Introduction to detonation deafness Knock deafness refers to sudden shocks and transient strong impulse noise and hearing impairment caused by the hearing, often caused by an explosion during a peacetime war. The main injury site is in the inner ear, but often the tympanic membrane or ossicular chain also has different degrees of damage. The degree of caries is often the distance from the source, the magnitude of the shock wave, the length of the earthquake, the position of the head, and the obstacles. Related, individual sensibility is also different. The basic principles of dietary health care for the ear are: light, mainly rice, noodles, beans, vegetables and fruits; moderate consumption of lean meat, eggs and animal kidneys, etc., to avoid the spicy and spicy products, to quit smoking and alcohol. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific people Mode of infection: non-infectious Complications: hearing impairment
Cause
Cause of deafness deafness
1. Mechanical damage
The strong positive pressure wave occurs instantaneously to rupture the tympanic membrane. According to the experiment, the critical perforation pressure of the tympanic membrane is 0.18kg/cm2, and the positive wave of up to 3000kg/cm2 can break through the tympanic membrane, displace the ossicle, bleed the chamber, and listen to the bone chain and the snail. The window acts on the inner and outer lymph fluids, causing the endolymph to fluctuate drastically, causing necrosis of the auger and hair cells.
2. Metabolic disorders
Detonation causes SDH (succinate dehydrogenase) in hair cells, decreased activity of MDH (malate dehydrogenase), swelling of vascular endothelial cells, obstruction of blood flow and cell degeneration, and detonation waves can cause rupture of bleeding elsewhere in the body. And crush injury, the larger the peak value of the detonation wave, or the longer the exposure time or repeated damage, the more serious the damage, the tympanic membrane can be expressed as blood stasis, turbidity or perforation according to the degree of injury, and the inner ear damage is not In the same way, the middle ear is severely damaged and the inner ear damage can be very light.
Prevention
Knock deafness prevention
1. Simple protection In the case of foresight, you should use favorable topographical features to avoid the overpressure of the detonation wave, prone or back to the heart, mouth and chewing and swallowing action, wearing a cap or headscarf with ear protection, by hand or The ears are covered with ears, oil cotton plugs and so on.
2. Work protection is very effective in using nuclear weapons, artillery shells, and bombs to prevent detonation.
3. Equipment protection such as various earplugs, earmuffs, anti-sound helmets, etc.
Complication
Knock deafness complications Complications, hearing impairment
The lighter can recover on his own within two weeks, while the severe ones are deaf and tinnitus for life.
Symptom
Cleavage deafness symptoms Common symptoms Tinnitus, earache, dizziness, tympanic membrane, congestive, deafness, coma
Inner ear
Generally, the lesion is transferred to the second middle of the cochlea, and the outer hair cells and the pillar cells of the spiral are degenerated, displaced or partially detached from the basement membrane. In severe cases, all the cells are severely degenerated and the augmentation disappears, and the cochlear ganglion is degenerated. Lymphatic hemorrhage, the vestibular part of the change is generally lighter.
Middle ear
The tympanic membrane can be mildly hyperemic to rupture, osseointegration or dislocation of the small bone, rupture of the tympanic nerve, and rupture of the col window membrane to cause perilymphatic sputum.
[clinical manifestations]
The knocking sputum is not like noise, and the degree of shock damage to both ears is not commensurate. It is not uncommon for a single ear to be damaged.
Deafness
Light is temporary, heavy is permanent, generally can not be recovered in the first half of the injury, that is, difficult to recover, deafness is sensory neurological or mixed, so the hearing curve is diversified, the typical 4000Hz valley curve is not much See, sometimes strong pops trigger psychological factors, causing central nervous system function inhibition, leading to functional paralysis, often accompanied by aphasia, etc., functional paralysis can coexist with knocking paralysis.
2. Tinnitus
The incidence rate is about 50% to 100%. The persistence is more frequent than intermittent, and the sensory is dominant. Some patients feel that the deafness is not heavy, and the main pain is severe high-pitched tinnitus.
Earache
The incidence rate is about 20%, mostly caused by rupture of the tympanic membrane, so it is short-term.
4. Dizziness
Patients with lost turbulence and lost bleeding may have dizziness, spontaneous nystagmus and balance disorders; those with concussion have coma, often vertigo, headache, dizziness.
5. Tympanic membrane damage or rupture
It can be seen that the tympanic membrane is congested, with ecchymosis or bleeding, and even rupture.
Examine
Examination of deafness deafness
Hearing tests show severe hearing impairment, even complete hearing loss, light can partially restore hearing, and severe cases can cause permanent deafness.
It can be seen that the tympanic membrane is congested, hemorrhagic, or perforated, with bloody sputum on the surface, and sometimes the dislocation of the ossicle is visible. The hearing test is mostly sensory sputum or mixed sputum. The hearing curve is mostly horizontal, the treble is steep or the slope is down. If there is a balance disorder, spontaneous nystagmus may occur, and the vestibular function may be dull or disappear.
Diagnosis
Diagnosis of deafness deafness
Different from other types of deafness.
