Air Bubbles: Diagnosing a Ruptured Tympanic Membrane

Air Bubbles: Diagnosing a Ruptured Tympanic Membrane
Air Bubbles

Air Bubbles

A 14 year-old female spayed DSH presented for head shaking, scratching at both ears and owner-reported decreased hearing for several weeks duration. Her medical history included chronic ear infections over several years, all treated with Tresaderm. The other cat in the house was healthy with no history of otitis.

On physical examination, the patient had brown ceruminous discharge, hyperemia of the ear canal, and pain in the left ear. She had mild ceruminous discharge in the right ear. She also had dental disease.

Ear cytology revealed 3+ cocci and 3+ yeast with no mites in the left ear and negative in the right ear. The client was asked to return the patient for a dental, ear flush and ear culture under general anesthesia the following day as long as the blood work and urinalysis were within normal limits. Blood work (Chemistry/CBC/T4) and a urinalysis were all within normal limits.

The patient was placed under general anesthesia and a routine dental with no extractions was performed. The OtoPet-USA Video Vetscope was used to evaluate both ears. The right ear had a small amount of cerumen and an intact tympanic membrane was visualized. The right ear was then cleaned with warm saline using the OtoPet-USA Earigator. The left ear had a large amount of discharge obstructing the view of the tympanic membrane.

When there is a large amount of exudate present in the ear canal a thorough deep ear cleaning may be needed to evaluate the tympanum. Warmed saline can be used to clean the ear and can be helpful in assessing if the tympanic membrane is ruptured. The anesthetized patient is placed in lateral recumbency with the affected ear up. The ear canal is filled with warmed saline and the VetScope probe is inserted into the ear canal. If air bubbles are seen in the saline that rise when the patient breathes, then the tympanic membrane is ruptured. Air from the nasopharynx rises through the auditory tube, into the tympanic bulla, and it escapes into the external ear canal through the ruptured tympanic membrane.

Water was gently placed into the left ear using the Earigator to determine if the membrane was intact, and air bubbles were visualized. View the video of air bubbles visualized and captured using the VetScope here. The ear was then gently cleaned with sterile saline using the Earigator after a sample from the middle ear was taken for bacterial culture and sensitivity.

Flushing the external ear and middle ear canals is an important step in treating otitis. Debris in the ear canal and middle ear can inactivate some topical medications and prevent medications from contacting the infected tissues, as well as perpetuate infection and stimulate inflammation.

She was sent home on the following oral medications: Fluconazole, a tapering dose of Prednisolone, and Clavamox pending the culture, as there were yeast and cocci on cytology. The bacterial culture revealed Staphylococcus, which is sensitive to Clavamox. Topical medications were not initially used. However, some clinicians may choose to instill antibiotic or steroid directly into the middle ear after cleaning the ear with visualization using the  VetScope, or dispense topical medications to be used at home.

At the 3 week re-check, both ears had intact tympanic membranes with the right ear clear and mild erythema and discharge in the left ear. Cytology was negative in the right ear and revealed 1+ yeast and 1+ cocci in the left ear. The Fluconazole and Clavamox were extended an additional 3 weeks and MalAcetic® ULTRA Otic (Dechra Veterinary Products) was dispensed for daily cleaning of the left ear. At the 6 week re-check both ears were clear with a negative cytology. Topical medications are typically administered until the external ear canal and tympanum appears normal, and cytologic examination of the ear canal is negative. The MalAcetic ULTRA Otic was tapered to every other week cleaning to help prevent reoccurrence of infection.