Results of an audiometry indicate that a patient has a 10-dB hearing loss at 8000 Hz. What is the most appropriate action by the nurse?

Ear assessment requires knowledge of normal tympanic membrane landmarks. The umbo, handle of malleus, and cone of light are expected findings and help the nurse distinguish a healthy eardrum from pathological changes. Recognizing these landmarks is essential for detecting abnormalities such as infection, fluid, or perforation.

Rationale for correct answer:

1. Major landmarks of the tympanic membrane include the umbo, handle of malleus, and cone of light: These structures are normal anatomical features that should be visible on otoscopic exam. Their presence helps confirm that the tympanic membrane is intact and healthy.

Rationale for incorrect answers:
2. The presence of a retracted eardrum on otoscopic examination is indicative of positive pressure in the middle ear: A retracted eardrum actually indicates negative pressure due to eustachian tube dysfunction, not positive pressure.
3. In chronic otitis media, the nurse would expect to find a lack of landmarks and a bulging eardrum on otoscopic examination: A bulging tympanic membrane is more typical of acute otitis media. Chronic otitis media usually shows scarring, perforation, or thickening, not acute bulging.
4. To straighten the ear canal in an adult before insertion of the otoscope, the nurse grasps the auricle and pulls downward and backward: For adults, the auricle should be pulled upward and backward. Downward and backward is correct for children under 3 years of age.

Take home points:

• Normal tympanic membrane landmarks include the umbo, handle of malleus, and cone of light.
• Retracted tympanic membrane = negative middle ear pressure, not positive.
• Bulging tympanic membrane = acute otitis media, while chronic cases show scarring or perforation.
• For otoscope insertion: pull the auricle up and back in adults, down and back in children <3 years.

Caloric testing is a diagnostic procedure used to evaluate the function of the vestibular system by irrigating the ear canal with warm or cold water and observing eye movements (nystagmus). A normal response is the development of nystagmus, which demonstrates intact vestibular function. Absence of nystagmus indicates abnormal vestibular function and is consistent with disease or dysfunction of the vestibular apparatus or nerve.

Rationale for correct answer:
2. No nystagmus is elicited with application of water in the external ear: The absence of nystagmus during caloric testing is abnormal and strongly suggests vestibular dysfunction. This means the labyrinth or vestibular nerve is not responding properly to stimulation, which helps in diagnosing inner ear disease.

Rationale for incorrect answers:

1. Hearing is improved with irrigation of the external ear canal: Improvement in hearing after irrigation usually indicates removal of impacted cerumen, which is unrelated to vestibular system function. This finding does not diagnose inner ear disease.

3. The patient experiences intolerable pain with irrigation of the external ear: Pain suggests an inflamed or infected external ear canal (otitis externa) but has nothing to do with the vestibular system’s integrity. It is not the purpose of caloric testing.

4. Irrigation of the external ear with water produces nystagmus opposite the side of instillation: Nystagmus is the normal expected response, indicating intact vestibular function. This would not point to disease, but rather to a healthy vestibular system.

Take home points:

• Normal caloric testing = nystagmus is elicited.
• Abnormal caloric testing = absence of nystagmus, which indicates vestibular dysfunction.
• The test helps distinguish inner ear and vestibular nerve disorders from other causes of dizziness or balance problems.