Pneumatic Otoscope Examination

Pneumatic otoscopy is an examination that allows determination of the mobility of a patient’s tympanic membrane (TM) in response to pressure changes. The normal tympanic membrane moves in response to pressure. Immobility may be due to fluid in the middle ear, a perforation, or tympanosclerosis, among other reasons. ^[1] The detection of middle ear effusion by pneumatic otoscopy is key in establishing the diagnosis of otitis media with effusion (OME). ^[2]

The predictive value of visible eardrum characteristics for OME ranges widely. ^[3] Therefore, pneumatic otoscopy is important, as it can indicate the presence of effusion even when the appearance of the eardrum otherwise gives no indication of middle ear pathology. Pneumatic otoscopy has been found to have a high sensitivity and specificity for diagnosing middle ear effusion. ^{[4, 5, 6, 7]} It has also been shown to do as well as or better than tympanometry and acoustic reflectometry, and it is especially useful in a setting in which tympanometry is not readily available. ^[8] Other advantages are that it is cheap and easy to perform with appropriate training.

Relevant Anatomy

The primary functionality of the middle ear (tympanic cavity) is that of bony conduction of sound via transference of sound waves in the air collected by the auricle to the fluid of the inner ear. The middle ear inhabits the petrous portion of the temporal bone and is filled with air secondary to communication with the nasopharynx via the auditory (eustachian) tube.

The tympanic membrane (TM) is an oval, thin, semi-transparent membrane that separates the external and middle ear (tympanic cavity). The TM is divided into 2 parts: the pars flaccida and the pars tensa. The manubrium of the malleus is firmly attached to the medial tympanic membrane; where the manubrium draws the TM medially, a concavity is formed. The apex of this concavity is called the umbo. The area of the TM superior to the umbo is termed the pars flaccida; the remainder of the TM is the pars tensa.

For more information about the relevant anatomy, see Ear Anatomy.

The diagnostic evaluation of suspected otitis media with effusion (OME) should include pneumatic otoscopy. ^{[2, 9, 10, 8, 11]} Pneumatic otoscopy should be performed to assess for OME in a child with otalgia, hearing loss, or both. ^[11]  Pneumatic otoscopy is a quick, painless test that takes a few minutes to complete.

OME is a very common problem in early childhood and is responsible for substantial morbidity. ^{[12, 13, 14, 15]} Most children have at least 1 episode during their childhood; many have repeated episodes. ^{[13, 14, 15, 16, 17]} OME frequently is associated with conductive hearing loss, which is usually transient; however, it has also been associated with delayed speech and language development. ^{[18, 19, 20]}

The history and physical examination may raise suspicion for OME, but diagnosis is confirmed by establishing the presence of a middle ear effusion. Siegle first described the principles and use of pneumatic otoscopy for detecting effusion more than a century ago. This was popularized by Politzer in 1909. ^[21]

Apart from the technical difficulty of obtaining an adequate seal, no contraindications exist for pneumatic otoscopy.

Great care and small pressure changes should be employed in patients with a very thin tympanic membrane or segment to avoid discomfort or perforation.

No anesthesia is necessary in routine pneumatic otoscopy, and its use is discouraged.

See the list below:

• Pneumatic otoscope (see image below)

  Otoscope with pneumatic attachment.

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• Siegle speculum (see images below)

  Siegle speculum and ear speculum disassembled. Note the slant on the lens of the speculum to avoid reflecting light into the eyes of the clinician.

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  Siegle speculum assembled.

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See the list below:

• The child should lie down with his or her head turned to one side; a smaller child should sit on a parent’s lap and rest his or her head on the parent’s chest.

• The parent holds the child, using one arm to secure the head and the other to hold both arms. If necessary to obtain a stable view, the parent’s legs can be crossed over the child's legs.

• The older child or adult can sit and tilt his or her head to one side.

• The patient must remain very still. Most patients who undergo this procedure are children; the parent’s cooperation is needed to keep the child calm.

• Insert the Siegle speculum in the patient's ear. See image below.

  Photo demonstrating the use of the Siegle speculum and head mirror, providing very good illumination and optical clarity.

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• Hold the Siegle speculum with the first and second fingers. Place the third finger in the concha and the fourth finger behind the ear to provide retraction. See image below.

  Correct hand positioning for using the Siegle speculum. The first and second fingers are holding the speculum while the third and fourth fingers are in the concha and behind the ear, respectively, to provide retraction.

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See the list below:

• Select the speculum size that best fits the external ear canal.

• Test to assure that the pneumatic system is leak-free. To do this, squeeze the bulb, place the tip of the speculum against a fingertip, release the bulb, and confirm suction on the fingertip.

• Advise the patient to stay still.

• Gently pull the ear backward to straighten the ear canal and get a better view of the tympanic membrane.

• Insert the otoscope far enough to create a good seal; this prevents air leakage between the speculum and ear canal wall. Take care not to insert the device too deeply.

• Inspect the ear canal and eardrum.

• Remove any excessive earwax (cerumen).

• Assess color, translucency, and position of the tympanic membrane. A normal tympanic membrane is convex, translucent, and intact.

• Gently squeeze the bulb on the otoscope to create positive pressure on the tympanic membrane and observe the degree of tympanic membrane mobility.

• Release the bulb to create negative pressure on the tympanic membrane and observe the degree of tympanic membrane mobility.

• Crisp movement of the tympanic membrane with slight application of pressure is normal.

  Pneumatic otoscopy. Courtesy of Hamid R Djalilian, MD.

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• Thickening of the tympanic membrane causes it to be less mobile.

• If the tympanic membrane does not move with applications of slight positive or negative pressure, a middle ear effusion is highly likely. ^{[3, 22, 23]}

• Note that almost any eardrum moves if enough pressure is applied.

• Sometimes application of pressure reveals an air-fluid level behind the tympanic membrane; this is diagnostic of a middle ear effusion. ^[24]

See the list below:

• An airtight system, properly functioning equipment, and a good seal in the ear canal are all vital to a successful examination. Otherwise, a false-positive diagnosis of middle ear effusion may occur (ie, impaired movement of the tympanic membrane in the absence of middle ear fluid).

• If unable to achieve a proper fit for an airtight seal, the clinician should reposition his or her arm to change the angle of the speculum.

• A seal cannot be obtained in the presence of a perforation or a patent ventilation tube.

• If the tympanic membrane is fully retracted and does not move with positive pressure, break the seal, gently compress the bulb, and reexamine the ear, starting with negative pressure. This may return the tympanic membrane to a neutral position and allow an assessment of mobility.

See the list below:

• Pneumatic otoscopy is a safe and normally pain-free procedure. On occasion, a small amount of discomfort may be experienced by the patient.

• If the patient has a perforation and a perilymph fistula, nystagmus, dizziness, vertigo, imbalance, nausea, and vomiting may occur (as with the fistula test).

• Theoretically, this procedure could cause a tympanic membrane perforation, most of which should heal spontaneously.

• Further possible complications include ossicular discontinuity and sensorineural deafness.