Which type of speculum should be used to examine a patients tympanic membrane

Otoscopic Examination

The remainder of the examination of the ear is performed with the otoscope. The otoscope incorporates a halogen light source and fiberoptic circumferential distribution of the light. This provides a 360-degree ring of light-conducting fibers within the shell of the otoscope through which the observer views the inner structures of the ear. Most otoscopes are illuminated by a bright quartz halogen bulb requiring a 3.5-V power supply. Specially designed reusable or disposable polypropylene specula slip over the tip of the instrument. Most otoscopic heads can be used with a rubber squeeze bulb for pneumatic otoscopy (described later in this chapter). Take care in the use of the otoscope. The best visualization of the structure does not require the speculum to be wedged into the canal. Be gentle to achieve the best view of the anatomy.

Choose the correct speculum size: small enough to prevent discomfort to the patient and large enough to provide an adequate beam of light. Usually a tip 4 to 6 mm in diameter is used for adults, 3 to 4 mm in diameter for children, and 2 mm in diameter for infants.

What To Do

Use an otoscope to inspect the ear canal while pulling up and back on the pinna to help straighten the ear canal, thereby providing a better view.

If there is a live insect in the patient’s ear, begin by filling the canal with a liquid to kill the insect. Mineral oil, 2% lidocaine (Xylocaine), or benzocaine/antipyrine (Auralgan) works well. (Sterile 2% lidocaine would be most appropriate if there is a myringotomy tube in place or any other opening of the tympanic membrane [TM].) Instruct the patient to lie on his or her side, and then drip the liquid into the canal while pulling on the pinna and pushing on the tragus to remove air bubbles (Figure 28-1).

With a foreign body (FB) that is not too tightly wedged in the canal, and if tympanic membrane perforation or a myringotomy tube is not present, water irrigation is a very effective removal technique. This can be accomplished with a syringe and scalp vein needle that has been cut short (Figure 28-2). Tap water at body temperature can be used to flush out the foreign body. Direct the stream along the wall of the canal and around the object, thereby flushing it out (Figure 28-3).

If a hard or spherical object remains tightly wedged in the canal, attempt to roll the foreign body out by getting behind it with a right-angle nerve hook, ear curette, or wire loop. (Alternatively, a Calgiswab can be bent into a right-angle hook and used in the same way.) Use of these tools should be done under direct vision through an ear speculum. The patient’s head should be firmly stabilized to prevent sudden movements. Whenever an instrument is used in the ear canal, warn the patient or parents beforehand that there may be a small amount of bleeding and pain because of the delicate lining of the ear canal (Figures 28-4 and 28-5).

An alternative removal technique is to take a drop or two of cyanoacrylate (Super Glue, Dermabond), and place it on the end of the wooden shaft of a cotton swab. (Use the cotton end for irregular FBs.) Then hold the wet glue against the foreign object until it hardens (approximately 30 seconds to a minute), and extract the foreign body from the canal.

If the object is light and moves easily, you can attempt to suction it out with a standard metal suction tip or (if available) a specialized flexible tip, by making an effective vacuum seal on the foreign body (Figure 28-6).

A small magnet or iron-containing metallic foreign body can be removed by touching a pacemaker magnet to a metal forceps and then, at the same time, touching the forceps to the foreign body, withdrawing all of the magnetized objects together.

Alligator forceps are good for grasping soft objects, such as cotton, paper, and certain insects.

There should be no delay in removing a foreign body in a canal when there is an obvious infection or when the foreign body is a disk or button battery. Do not irrigate or instill liquids into the ear canal, because on contact with moist tissue, the alkaline battery is capable of producing a liquefactive necrosis extending into deep tissues within hours. Be careful not to crush the battery. After removal of a battery, irrigate the canal to remove any alkali residue.

At any time, if a child becomes uncooperative, especially when using metal instruments, use procedural sedation as described in Appendix E. Ketamine sedation appears to have a positive effect on the success rate of foreign body removal in children.

If the foreign body is tightly wedged in the canal and you cannot remove it, consult an ear-nose-throat (ENT) specialist. If after removal, there is evidence of infection or perforation of the tympanic membrane, referral to an ENT specialist is also appropriate.

Tympanic Membrane Thermometers.

Tympanic membrane thermometers use an otoscope-like probe that is inserted into the external auditory canal to detect and measure thermal infrared energy emitted from the tympanic membrane (Fig. 22-2). A scan button is pressed to start the measurement, and an audible signal indicates that the temperature is ready to be recorded from the digital display.

Tympanic thermometers are minimally invasive, record temperatures in approximately 3 seconds, register temperatures in the range of 25°-43° C, have no direct contact with mucous membranes, and work only if the disposable probe cover is in place.4 The probe lens, however, can be easily damaged if not handled carefully. It is important to check the lens before each use and to replace its protective cover when not in use.4 Operator handedness, patient position, and ear (right or left) have been shown not to produce clinically significant variability,5 although mean tympanic measurements from a single ear were found to agree less than the mean of both ears when compared to temperature measurement by pulmonary artery catheter.6 Obstruction of the tympanic membrane by cerumen may lower tympanic measurements.7

Tympanic thermometers have been found to be accurate, easily usable clinically,8 and satisfactory for routine intermittent temperature measurement.9 They are as accurate as indwelling rectal probes and are suitable for estimating core temperature when a pulmonary artery catheter is not in place or is contraindicated.10 Tympanic membrane thermometers are the most sensitive noninvasive devices for measuring body temperature greater than 37.5° C and are better for detecting temperature shifts after acetaminophen than single-use or mercury-in glass-thermometers.11 Some authors find tympanic and oral electronic thermometer measurements equally acceptable if pulmonary artery catheter and rectal temperatures are not available or contraindicated.12

Significant variations in temperature measurement have been found among different types and makes of tympanic thermometers,10,13,14 which may be attributed at least in part to different people using the devices.5 Even though the tympanic thermometer produces more variable results, the mean readings are not significantly different from those taken with a mercury-in-glass thermometer.15 Inaccuracies are more likely in children if the thermometer is calibrated for an adult, the incorrect size probe is used, or if the child is less than 1 year old where even the smallest tip available is likely to fit poorly.14,16 Additionally, inaccuracies may occur with incorrect positioning,10 leading some researchers to recommend that an electronic oral measurement be taken before a tympanic measurement to first check if they correlate.17

Physical examination

Nasal examination can be performed with a handheld otoscope or nasal speculum that permits viewing of the anterior third of the nasal airway, including the anterior tip of the inferior turbinates (and occasionally the anterior tip of the middle turbinates) and portions of the nasal septum.1–3 However, fiberoptic rhinoscopy may be required to visualize other abnormalities, such as nasal polyps, septal deviation, or masses. Typically, patients with AR have a clear discharge, swollen turbinates, and bluish or pale mucosa. Pale or erythematous mucosa can be seen in various types of nonallergic rhinitis. Both allergic and nonallergic rhinitis can cause ‘allergic shiners,’ infraorbital darkening attributed to chronic venous pooling, or a persistent horizontal crease across the nose in children who rub their noses upward because of nasal discomfort – the so-called ‘allergic salute.’ In association with rhinitis, the presence of mild bilateral conjunctivitis is suggestive of allergy. Patients with nasal disease require appropriate examination for associated diseases, such as sinusitis, otitis media and asthma.1–3

Diagnosis