Deafness

Deafness - medical nursing

1. Deafness Mr. Binu Babu M.Sc. Nursing Mrs. Jincy Ealias M.Sc. Nursing

2. Definition Deafness, Hearing impairment or hearing loss refers to the total or partial inability to hear.

3. Types   Conductive hearing loss ( CHL) Sensorineural hearing loss (SHL) Mixed hearing loss ( MHL ) Others Central hearing loss Functional hearing loss Malingering

4. Conductive hearing loss Conductive hearing loss is any interference with the conduction of sound impulses through the external auditory canal , the eardrum, or the middle ear .

5. Conductive hearing loss can be caused by anything that interferes with the ability of the sound wave to reach the inner ear such as cerumen, foreign bodies, infection .

6. Sensorineural hearing loss Sensory hearing loss originates in the cochlea and involves the hair cells and nerve endings . Sensorineural hearing loss results from disease or trauma to the sensory or neural components of the inner ear.

7. Presbycusis is hearing loss caused by the aging process that results from degeneration of the organ of Corti . This degenerative process usually begins at 50 yrs of age.

8. Mixed hearing loss Mixed hearing loss occurs when an individual has both conductive and sensorineural hearing loss. This can be caused by a combination of any of the disorders

9. Central hearing loss Central hearing loss occurs when the central nervous system cannot interpret normal auditory signals. This condition occurs with such disorders as cerebrovascular accidents and tumors .

10. Functional hearing loss Functional hearing loss is a hearing loss for which no organic cause or lesion can be found . Also called psychogenic hearing loss. Precipitated by emotional stress. Malingering is a type of psychogenic hearing loss. In Malingering, there is no organic or psychological cause. The patient is pretending to be deaf for personal gains.

11. Severity of hearing loss Loss in Decibels Interpretation 0–15 Normal hearing >15–25 Slight hearing loss >25–40 Mild hearing loss > 40–55 Moderate hearing loss > 55–70 Moderate to severe hearing loss > 70–90 Severe hearing loss >90 Profound hearing loss

12. Etiology Age: increasing age Exposure to loud noise Genetic Head injury Ototoxic drugs Illness

13. Illness Ear infections Measles may cause auditory nerve damage Meningitis may damage auditory nerve or cochlea Auto immune disease Mumps Otosclerosis Medulloblastoma or other brain tumors Syphilis from pregnant woman to fetus Premature birth Fetal alcohol syndrome in infants of alcoholic mothers Neurological disorders Multiple sclerosis Stroke

14. Risk Factors Family history of sensorineural impairment Congenital malformations of the cranial structure (ear) Low birth weight (1500 g) Use of ototoxic medications ( eg:gentamycin , loop diuretics ) Recurrent ear infections Bacterial meningitis Chronic exposure to loud noises Perforation of the tympanic membrane

15. Causes of Conductive deafness EXTERNAL EAR: Impacted Wax Otitis Externa Foreign Bodies Polyps Tumours Fluid in the ear MIDDLE EAR Congenital defects of the ear drum and ossicles . Perforation of the tympanic membrane Traumatic : Barotrauma, rupture of ear drum , skull fracture Inflammation : AOM, COM, Neoplasms Otosclerosis

16. Causes of sensorineural deafness INNER EAR Congenital Trauma : Head injury, surgical injury to labyrinth, loud sounds producing concussion. Infections : mumps, syphilis, tuberculous meningitis, enteric fever, labyrinthitis . Presbycusis Tumours : Acoustic neuroma Meniere’s disease Ototoxic drugs: streptomycin, Kanamycin, neomycin, salicylates, frusemide and quinine.

17. Causes of Central hearing loss Cerebrovascular accidents Brain tumors Multiple sclerosis

18. Pathophysiology Disorders of external or middle ear Interruption in the transmission of sound by air to the inner ear Conductive deafness

19. Disorders of inner ear or vestibulocochlear nerve or aging Interruption in neural transmission of sound to brain Sensorineural deafness

20. Clinical manifestations Tinnitus Increasing inability to hear when in a group Need to turn up the volume of the television Failure to respond or In appropriate response to oral communications Excessively loud speech Strained facial expression Constant need for clarification of conversation  Social withdrawal

21. Diagnostic measures History Physical examination Rinne’s test Weber’s test Audiometry Tympanogram

22. COMPARISON OF WEBER AND RINNE TESTS Hearing Status Weber Rinne Normal hearing Sound is heard equally in both ears. Air conduction is audible longer than bone conduction. Conductive hearing loss Sound is heard best in affected ear (hearing loss). Sound is heard as long or longer in affected ear (hearing loss). Sensorineural hearing loss Sound is heard best in normal hearing ear. Air conduction is audible longer than bone conduction in affected ear.

23. Prevention Minimize the exposure to trauma, infection, ototoxic drugs. Avoid the risk factors. Wear ear protection to prevent noise-induced hearing loss when exposed to loud noise.

24. Management Medical management Restore hearing Antibiotics: to treat infections Remove impacted wax or foreign bodies Ceruminolytics for impacted wax Corticosteroids for inflammation Treat underlying disorders

25.  Assist hearing Hearing aids Implantable middle ear hearing devices Cochlear implants Sign language Auditory rehabilitation

26. Hearing aids : Hearing aid is designed to amplify sound Implantable middle ear hearing devices : Implantable middle ear hearing aids are implanted surgically, can improve sound perception for patients with moderate-to-severe sensorineural hearing loss .

27. Cochlear implants: Cochlear implants are surgically placed electrical devices that receive sound and transmit the resulting electrical signal to electrodes implanted in the cochlear of the ear. Sign language : It involves hand shapes, movement of hands, arms, body and facial expressions

28. Aural rehabilitation

29. Aural rehabilitation refers to services and procedures for facilitating adequate receptive and expressive communication in individuals with hearing impairment. If a hearing loss is permanent or untreatable, aural rehabilitation may be beneficial.

30. Purpose To maximize the communication skills of the person with hearing impairment.

31. Components Auditory training : Auditory training emphasizes listening skills, so the person who is hearing-impaired concentrates on the speaker. Speech reading : Also known as lip reading. Speech reading can help fill the gaps left by missed or misheard words. Speech training : The goals of speech training are to conserve, develop, and prevent deterioration of current communication skills.

32. Hearing Aids: A hearing aid is a device through which speech and environmental sounds are received by a microphone, converted to electrical signals, amplified, and reconverted to acoustic signals .

33. Hearing Guide Dogs: Specially trained dogs (service dogs) are available to assist the person with a hearing loss. People who live alone are eligible to apply for a dog trained by International Hearing Dog , Inc. The dog reacts to the sound of a telephone, a doorbell, an alarm clock, a baby’s cry, a knock at the door , a smoke alarm, or an intruder. The dog alerts its master by physical contact; the dog then runs to the source of the noise. In public, the dog positions itself between the person with hearing impairment and any potential hazard that the person cannot hear, such as an oncoming vehicle or a loud, hostile person.

34. Surgical management Surgery is indicated for conductive or mixed hearing loss. To restore conductive hearing Myringotomy Stapedectomy Assisted hearing in profound deafness Cochlear implants Middle ear implants (Semi-implantable hearing device) Tumour excision for acoustic neuroma

35. Nursing Diagnosis Disturbed sensory perception: hearing related to altered sensory reception and transmission Impaired verbal communication related to impaired hearing Impaired social interaction related to impaired hearing and decreased communication skills Disturbed body image related to impaired hearing and use of assistive hearing devices Ineffective coping related to difficult communication Deficient knowledge related to care of hearing aid due to lack of prior experience

36. Nursing interventions Inspect ear canals for mechanical obstruction . Remove mechanical obstructions like cerumen or foreign bodies. Assess hearing by use of a tuning fork, or verbal cues to determine auditory ability at various distances . Speak slowly with careful pronunciation of words. Add hand gestures, speak face to face and adjust pitch downward without increasing volume. Introduce assistive devices such as hearing aids, written communication , and sign language . Allow patient to verbalize feelings and grieving about hearing loss.