Otitis 2 Flashcards
Evaluate the use of povidone iodine as an otic flushing solution
- Recommended by some but others state ototoxicity
- May be useful if Proteus is present
Evaluate the use of saline as an otic flushing solution
Safe, widely available, sterile
Evaluate the use of chlorhexidine as an otic flushing solution
- Problematic at higher concentrations
- 0.15% safe in dogs but not cats
- Use TRIZChlor flush only, any higher concentration is ototoxic
When should cerumolytics, aqueous solutions and drying agents be used as flushing solutions?
Only when the drum is known to be in tact
Evaluate the use of cerumolytics as an otic flushing solution and give examples
To emulsify ear wax for easy removal, e.g. squalene, alcohols
Evaluate the use of aqueous solutions as an otic flushing solution
Aid in removal of pus, mucus and serum from the ears
Evaluate the use of drying agents as an otic flushing solution and give an example
Decrease moisture in ears and dessicate the surface keratinocytes, e.g. boric acid
Outline the anaesthetic requirement during ear flushing
- Required in severe/chronic cases
- ET tube protects from aspiration of flushing solution via eustachian tube
- Hearing often present even with sedation
- Allows adequate assessment of the ear, especially if painful
Outline the disadvantages and advantages of the manual otoscope and syringe method for ear flushing
- Spreul needle used, but reusable and often damaged with sharp edges, disposable better
- Cut down gauge 6 urinary catheter
- Large catheter cover
- Precise but time consuming
- can make ear sore through rubbing of speculum, premed with steroids at least one day before
- Equipment inexpensive
Outline the disadvantages and advantages of the video otoscopy method for ear flushing
- Precise
- Able to record data if data capture technique
- Custom made curettes, biopsy and grabbing tools available
- Small bore channel means slow cleaning in some cases
- May not fit the smallest ears
What are the aims of otitis treatment?
- Remove/reduce microbes
- Reduce swelling, discomfort or pain
- Normalise canal lumen and function
Give a key advantage and disadvantage of Aurizon ear treatment
- Broad spectrum
- But poor for diabetics
Give a key advantage and disadvantage of Easotic ear treatment
- Better for diabetics
- Poorly absorbed steroids
Give the key advantages and disadvantages of Osurnia ear treatment
Advantages:
- Good for incompetent owner or very painful dog
- Good anti-staph and anti-malassezia treatment
- First line treatment
Disadvantages
- Poor for Pseudomonas
- Poor for progressive disease
What is the main issue with all ear treatments?
All state not for use if ear drum not intact, but difficult to assess so need to go off license or avoid ototoxic drugs
List drugs which are ototoxic
- Gentamicin
- Polymyxin B
- Ticarcillin and imipene
- Propylene glycol
- Chlorhexidine at moderate concentrations
Outline a basic treatment for acute otitis
- Use first line ointment with antimicrobial, steroid and antifungal based on cytology and otoscopy
- Once to twice daily for 7-14 days
- Ensure use of sufficient amount )0.7-1ml for large dog)
- Combine with suitable cleaner e.g. TRIXChlor, Cleanaural, Malacetic otic
When presented with ear disease with a great deal of discharge and unclear time course, what would be a logical approach?
- Admit for flush etc., treat as chronic case
- Cannot be confident that disease has not been there for a while
List cytological indications for bacterial culture in otitis
- Rods seen, need suitable antibiotic
- Marked purulent discharge without organisms noted
- Pyogranulomatous inflammation
Why is bacterial culture recommended in a case of otitis with pyogranulomatous inflammation?
- Organisms difficult to see with cytology in this uncommon ear inflammation
- Culture obligatory
- Basement membrane breached, ulcerated ears
List the clinical infications for bacterial culture in otitis
- In the event of treatment failure
- If there is a suspicion of MRSP, MRSA, MRSS
- If considering video otoscopy or ear flush for diagnosis, or treatment in a bacterial otitis
Why is bacterial culture recommended in a case where video otoscopy is to be used?
Risk of adverse event following these procedures e.g. neurological signs meaning that systemic antimicrobials may be required
When should an ear with otitis be re-checked?
Obligatory 7-10 days recheck
What should be assessed at the re-check for otitis?
- Improvement?
- Asses owner compliance
- Identification of next stage of treatment
- May need to restore epithelial migration
- Identificaiton of underlying cause
Outline the treatment recommended for teh treatment of chronic allergy leading to otitis
- Avoid use of antibiotics
- Control microflora through cleaning
- Use topical steroids to control inflammation
- Lokivetmab and oclacitanib are poor for ear disease, will commonly need a treatment for the body and a treatment for the ear
What is the importance of Pseumonas otitis?
Common cause of otitis - 35% of OE and/or OM and aggressive treatment required
What is Pseudomonas otitis commonly associated with?
- Poorly managed or untreated Malassezia or Staphylococcal otitis
- Immunosuppression
- Swimming
- Prior use of antibacterials
Describe the appearance of Pseudomonas otitis
- Swelling, pain, malodour common
- Often ulcerated
- Green to browny-black discharge
Outline the plan for Pseudomonas otitis with severe disease
- Always flush if purulent material
- Presume drum ruptured as a result of collagenase produced by bacteria
- Presume OM and likelihood of OI
- Warn owner of risks of flushing, treatment and disease itself e.g. Horner’s, facial paralysis, hearing loss
- Possibly TECA
- Use of non-licensed products e.g. OE medication such as Aurizon
- Bacteriology, flush and clean, disinfectant cleaner e.g. TRIZChlor, apply suitable antibiotic, provide anti-inflamm and analgesia
Outline a treatment plan for a dog with Pseudomonas otitis that has received little previous treatment
- Cleaning with saline
- Disinfect with TRIZChlor 10 minute soak
- Aurizon antibiotic
- Introperative opiod analgesia e.g. morphine
- Dexamethasone 0.3mg/kg IV at end of procedure
- Home on Aurizon ear cream 0.4-0.7ml BID for 7 days, TRIZChlor SID starting on day 4, prednisolone 0.5mg/kg SID PO
- Reassess at 7 days
- If doing well and marked chronic changes, increase dose of steroids, consider reducing frequency of drops and cleaner
Outline a treatment plan for a dog with Pseudomonas otitis that has been identified as a multi-resistant organism
- Cleaning with saline, disinfect with TRIZChlor 10 min soak
- Silver sulfadiazine antibiotic
- Intraoperative morphine, dexamethasone 0.2mg/kg IV at end of procedure
- Home on TRIZChlor BID, silver sulfadiazine 1:9 aqueous soln at least BID to fill ear (OR gentamicin, ticarcillin if suitable susceptibility data), pred 0.5mg/kg SID PO, pain relief
- Reassess at 5 days to allow complete flushing and disinfection
- Further otoscopy/fushing as needed
What can ear canal stenosis be a consequence of?
- Chronic low grade trauma
- Severe acute disease untreated
- Trauma
- Mcuinosis +/- confirmation in shar Pei
What are the potential approaches to a stenotic ear?
- Potent topical steroids
- Oral steroids (pred 1-2mg/kg PO)
- Tacrolimus 0.1% ointment
- Intralesional steroids
- Treatment can be concurrent with, or if inappropriate after infection control
Outline the use of potent topical steroids in the treatment of otic stenosis
- Commercial medications for extended course e.g. Easotic, Posatex, Aurizon
- Beware local and systemic steroid side effects esp. in small dogs
- Long periods of treatment needed
Outline the use of tacrolimus 0.1% ointment (topical ciclosporin) in the treatment of otic stenosis
Applied to ear twice daily with care (gloves)
Outline the use of intralesional steroids in the treatment of otic stenosis
Inject ring around canal using video otoscopy
What defines an ear as “end stage”?
If any, or a combination of the following becomes unacceptable
- Welfare of pet or family
- When ear disease of is intractable, or very quickly recurrent due to stenosis, marked granulation in middle ear, ceruminous and sebaceous gland hyperplasia
- Cost of repeated medical interventions is unacceptable
- Inability to treat ear by the owner
What procedures are available for the treatment of end stage ears?
ONLY Total Ear Canal Ablation (TECA)
Avoid antibiotics where possible
How can further otic disease be prevented once treated?
- Treat underlying disease
- Use cleaners to maintain clean dry ear, support epithelial migration, and small amounts of steroid in cleaner reduce inflammation
- Gently remove loose hair by shaving ears of thick haired dogs
- Avoid antibiotics where possible
List the products most suitable for use in Ttaphylococcal otitis
- Aurizon
- Easotic
- Posatex
- Also: canaural, osurnia, otomax, surolan
List the product suitable for Pseudomonas otitis before culture results are available
- Aurizon, Easotic, Otomax, Posatex, Surolan
- Products with polymyxin B, fluoroquinolones and gentamicin are suitable
When would the use of oral antibiotics in the treatment of otitis be indicated?
Where there are neurological signs present
Suggest ear ointment treatment options for a dog with severe otitis, with Pseudomonas present that is susceptible to gentamicin and ticarcillin, with a ruptured ear drum
- Gentamicin ototoxic as is Ticarcillin
- Can use off licence if careful
- Using injectable fluroquinolones in TRIZEDTA cleaner could be used as the concentration may exceed the MIC for resistant Pseudomonas aeruginosa
- Silver sulfadiazine also an option
What are the major indications for ear surgery?
- Trauma
- Aural haematoma
- Neoplasia
- Certain cases with chronic otitis externa
- Chronic otitis media (infection, middle ear polyps, cholesteatoma)
What are the indications for surgery of the pinna?
Trauma or neoplasia
Evaluate the need to repair trauma to the pinna surgically
- Depends on level of trauma, usually will heal on its own
- Often looks dramatic as can bleed a lot
- Repair of pinna does not tend to stay together well as dog shakes/rubs head
What is an important consideration when surgically repairing pinnal trauma?
Need to incorporate a part of pinnal cartilage into the suture to buttress the repair and avoid it being held just by the integument
List the most common benign and malignant neoplasms of the pinna of dogs
Benign:
- Pinnal histiocytoma
- Papilloma
Malignant:
- Mast cell tumour
- Squamous cell carcinoma
List the most common benign and malignant neoplasms of the pinna of cats
Benign:
- Basal cell tumour
Malignant:
- Squamous cell carcinoma
- Mast cell tumour
- Fibrosarcoma
Outline the surgical management of pinnal squamous cell carcinoma
Removal of pinna
What are the management options for aural haematoma?
- Surgical incision, drainage and suture
- Drainage with an indwelling drain
- Drainage and glucocorticoid instillation
- Closed suction drainage
What is the key principle in the management of an aural haematoma?
in all cases, need to remove blood then keep skin in close association with underlying cartilage while it heals
How should sutures be place on the pinna and why?
- Blood suppl comes in laterally and medially and runs vertically
- Do not place sutures on lateral planes - more likely to occlude blood supply
How can pressure be equalised on the sutures used on the pinna
Sutures can have short lengths of drip tube attached
How can close apposition of the pinnal integument and he cartilage be achieved?
- Stitch the integument to the cartilage
- Forces healing with scar tissue to hold the two together
- Use multiple interrupted sutures either full or partial thickness
Evaluate the use of bandages for ears
- Cut foam pads to correct shape and size then stitch on
- Bandage can prevent damage from head shaking but risk of making area too warm and moist
What surgical management options are available for otitis externa?
Lateral wall resection and vertical canal ablation
What are the indications for a lateral wall resection?
- Persistent/recurrent OE with mild, potentially reversible hyperplasia of epithelium and adnexae
- Neoplasia of lateral wall of vertical canal
- Rarely in management of OM to facilitate flushing and drainage of bulla
What structures are commonly implicated in external ear canal neoplasms?
Often ceruminous glands are involved, can be benign or malignant
List the benign and malignant neoplasms of the external ear canal of the dog
Benign:
- Papilloma
- Cutaneous histiocytoma
- Mast cell tumour
- Basal cell tumour
- Ceruminous gland adenoma
- Sebaceous gland adenoma
Malignant:
- Ceruminous gland adenocarcinoma
- other carcinomas
- Squamous cell carcinoma
List the benign and malignant neoplasms of the external ear canal of the cat
Benign:
- Ceruminous gland adenoma
Malignant:
- Cerumous gland adenocarcinoma
- Squamous cell carcinoma
- Other carcinoma
What is the main purpose of a lateral wall resection?
Will not cure the animal of underlying disease, but will improve the micro-environment of the ear. May allow easier treatment of ear as it allows medication to reach areas where it is required
Evaluate the role of lateral wall resections in the treatment of cancer
Only a small number of cancers are effectively resected with LWRs - only useful if cancer is situated in the lateral wall
Briefly outline the procedure for a lateral wall resection
- Incise skin down to level of horizontal canal, reflect dorsally.
- make parallel vertical incision either side of the vertical canal now visible, and reflect ventrally
- Remove the cartilage
- Stitch the skin to the remaining cartilage, placing sutures at the level of the horizontal canal first
What are the indications for vertical ablation?
- Where only the vertical canal is diseased
- Hyperplastic otitis externa, trauma, neoplastic disease and polyps restricted to the vertical ear canal
- Unlikely to be effective as a treatment for chronic otitis as the underlying ear disease is not resolved
Outline the procedure for a vertical canal ablation
- Lateral and medial wall of vertical canal removed
- Only horizontal canal in place, stitch skin together leaving an opening over the horizontal canal opening
What are the surgical management options for otitis media?
- Total Ear Canal Ablation and Bulla Osteotomy (TECA BO)
- Ventral bullaosteotomy
What are the indications for a TECA BO?
- Chronic/recurrent OE assocaited with irreveseible, hyperplastic changes in the luminal epithelium
- Failure of more conservative surgery to alleviate OE/OM
- Neoplasia of external ear canal
- Otitis media
What are the disadvantages of a TECA BO?
- Technically difficult
- Potentially for significant life-threatening complications
- Should not be attempted by inexperienced surgeons
Outline the procedure for a TECA BO
- Incision around opening of vertical canal on pinna, and T shaped incsion down lateral wall of vertical canal
- Cut through cartilage to to free up auricular portion of external ear canal i.e. vertical canal
- Dissect down to canal and to skull at annular cartilage
- Once at external acoustic meatus, cut and remove
- need to move all cartilage running down to TM
- Make hole into middle ear cavity
- Remove all integument of external ear canal
- Close completely
When is a ventral bulla osteotomy indicated?
- Indicated in cases with middle ear disease where TECA is not indicated
- Certain brachy breeds of dog
- Often in cat due to anatomy of bulla and inflammatory polypoid disease in absence of chronic OE
Outline the procedure for a ventral bulla osteotomy
- Enter ventrally, under skull between mandibles
- Lateral approach
- Care re. material on bulla which contains post-ganglionic fibres to eye
What surgical treatments are indicated for a cholesteatoma?
TECA BO or VBO
Outline what causes a cholesteatoma and the clinical signs
- Arise when TM comes into contact with and adheres to inflamed mucosa in middle ear
- Cystic lesion lined with stratified squamous epithelium and keratin squames
- Similar signs to any animal with middle and external ear disease: head tilt, scratching, Horners possible
Describe the aetiology of inflammatory polyps in cats
- Largely unknown
- more common in younger cats, but can occur in older as well as dogs
- Associated with infections commonly, esp. early exposure to cat flu/resp virus
Where do to inflammatory polyps emanate from the tympanic bulla to? How?
- Nasopharynx (via eustachian tube)
- Horizontal ear canal (from laterodorsal compartment through TM)
What are the consequences of inflammatory polyps in cats?
- Otitis media
- Leads to inflammatory, non-cancerous growths
- May block drainage of middle ear, leading to build up of secretions
Describe the clinical signs of inflammatory polyps in cats
- Often present with condition due to blockage of nasopharynx e.g. mouth breathing, difficulty swallowing
- Often not considered as ear disease
- Radiographically look the same as infection
Outline the removal of inflammatory polyps in cats
- Traction removal: palpate orally using spay hook, remove by grasping and pushing down throat without breaking stalk, towards oesophagus and will come away as single structure
- Otherwise can allow to resolve by itself
- Examine ear canals in case of polyps
Compare the anatomy of the canine and feline middle ear
- Cats have 2 separate compartments, separated by bony wall
- Larger ventromedial compartment, smaller dorso-lateral
- External ear canal joins smaller to larger
List the proposed causes of associations of aural haematomas
- Otodectes cynotis
- Otitis externa
- Trauma
- Autoimmunity
- Hypersensitivity
- Any cause involving pruritus
List potential complications of drainage of aural haematomas
- Cosmetic alterations (scar tissue and mis-shapen ear common)
- Recurrence of haematoma (common)
- Pinnal necrosis
List potential complications of lateral wall resections
- Few cancers resolved by LWRs
- Post-op pain/discomfort
- Incisional dehiscence
- Persistent OE
- Persistent, unrecognised OM
- Failure to provide adequate drainage of horizontal canal leading to horizontal canal stenosis
What increases the risk of incisional dehiscence following otic surgery?
High level of contamination
List the potential complications of vertical canal ablations
- Post-op pain/discomfort
- Incisional dehiscence
- Persistent OE
- Persistent, unrecognised OM
- Stenosis of horizontal canal
- Facial paralysis
List the potential complications of a TECA BO
- Post-op pain/discomfort
- Deafness
- Incisional dehiscence
- Facial nerve paralysis
- Vestibular disturbances e.g. nystagmus, nausea
- Haemorrhage
- Horner’s syndrome
- Recurrences/abscess formation
What condition do the following clinical signs indicate?
Anisocoria with ipsilateral miosis, ptosis of upper eyelid, narrowing of palpebral fissue, enophthalms, protrusion of third eyelid
Horner’s syndrome
List the potential complications of a VBO
- Post-op pain/discomfort
- Deafness
- Incisional dehiscence
- Facial nerve paralysis
- Vestibular disturbances
- Haemorrhage
- Horner’s syndrome
- Recurrence, abscess formation
