Page 2303 - Cote clinical veterinary advisor dogs and cats 4th

Otoscopy, Video 1145

Myringotomy: • Not using systemic corticosteroids before ○ Pretreat canal(s) with a ceruminolytic
agent.
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• 5 2 -inch, open-ended tomcat catheter ear flushing can prevent adequate access to ○ Premedicate, induce general anesthesia,
VetBooks.ir • Sterile saline of procedural-induced stenosis. In severe ○ Patient is positioned in lateral recumbency,
the tympanum and results in a higher risk
• Sterile culturettes for submission of samples
and intubate.
for culture and sensitivity
and chronic cases, repeated intralesional
ideally on a tub table.
• Injectible antibiotic for infusion into bulla
• Optional: suction unit, flushing and suction corticosteroid injections may be needed to ○ Position yourself dorsal to the patient’s
render the canal accessible for video-otoscopic
apparatus, three-way stopcock, a third large- access. However, if the otitis is that severe, head.
volume syringe or intravenous (IV) fluid ablation surgery is probably indicated. ○ Remember to examine the “good” ear first.
administration set ○ Introduce the modified 5-Fr urinary
Procedure catheter through the working channel of
Anticipated Time • Use disinfected otoscope tips for each animal the otoscope until the tip is visible.
• Ear examination: <5 minutes per ear in a (follow manufacturer recommendation for ○ Assistant fills and attaches the large-volume
conscious, nonsedate animal video-otoscopes). syringe containing soapy water to the
• Ear flushing: 10-20 minutes per ear • Examine the good ear first, even if the patient other end and proceeds to flush using
• Myringotomy/biopsy: 10-20 minutes presents with unilateral disease. small pulses while you direct catheter tip Procedures and Techniques
additional to ear flushing • For painful ears, injectable sedation and as needed to dislodge debris. Use grasp-
analgesia are essential (see back cover for ers for larger chunks of debris. Remove
Preparation: Important protocols). debris adhered to the tympanum using
Checkpoints • Collect cytologic samples from both canals. the blunt catheter tip and curette to reveal
Ear examination: Submit cultures from canals that are refrac- the tympanic membrane.
• Avoid instilling topical medication or clean- tory to treatment or frequently relapse. ○ Suction the canal, flush with warm water,
ing solutions in the ear 48 to 72 hours before. • Otoscopy in the awake patient is the same suction again, flush with warm saline
Ear flushing: for handheld and video: solution, and then suction completely
• Consider antiinflammatory doses of systemic ○ Use adequate restraint of the head to dry before making a final assessment
corticosteroids (e.g., prednisone 0.5-1 mg/ minimize movement. of the tympanum. When viewing the
kg PO q 24h) for 4-5 days before to prevent ○ Position the head so the muzzle is tympanum through a fluid interface,
procedural-induced canal stenosis. angled slightly toward the side opposite even the normal eardrum appears white
• Collect cytologic and culture samples of the of you. and opaque because light is refracted as
external canal before cleaning. ○ Pull the pinna away from the skull to it passes through the fluid-ear interface
• Pretreat canal with a ceruminolytic straighten the canal. demarcated by the tympanum.
agent before administering preanesthetic ○ Gently introduce the scope tip into the canal ○ At this point, be prepared to perform other
medication. via the intertragic incisure (just caudal to procedures such as biopsy, polyp removal,
the tragus), then visually guide the scope or myringotomy (when the tympanum is
Possible Complications and deeper into the canal, examining the walls opaque or not intact).
Common Errors to Avoid as you move toward and then past the Myringotomy if indicated:
• Otoscopy: causing pain vertical-horizontal canal junction. Be aware ○ Change flush catheter to 5 2 -inch, open-
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• Ear flushing: vestibular signs, deafness, of the Noxon fold at the dorsal aspect of this ended tomcat catheter.
Horner’s syndrome, and inadvertent tym- junction, and maneuver the scope gently ○ Repeatedly flush, then suction sterile saline
panic membrane rupture are uncommon past it. (1-mL volumes) to clear out infectious
but possible complications and usually are • Ear flushing debris.
transient. These can be avoided through ○ Collect cytologic and culture samples first. ○ Save the first 1 mL for culture.
adequate analgesia/anesthesia, excellent
visualization, and careful manipulation of
instruments in proximity of the tympanum. Manubrium of malleus Pars flaccida
Left (AS)
eardrum post flush
Purulent debris #5 French catheter
flushed from the passed into
tympanic bulla bulla to facilitate
flushing

Polyp just superficial
to a pathologically Exceptional bony prominence of Pars tensa
ruptured tympanum the bony external acoustic meatus
OTOSCOPY Intractable and chronic otitis treated by total ablation and lateral OTOSCOPY Otoscopic view of a normal proximal ear canal and tympanum.
bullectomy. (Courtesy Dr. Jeffrey M. Person.) (Courtesy Dr. Jeffrey M. Person.)

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