Upper Airway Flashcards
History/ clinical signs associated with nasal dz?
Nasal discharge Sneezing Reverse sneezing Stertor Epistaxis Facial deformation Ocular discharge
T/F: rhinoscopy and nasopharngoscopy should be performed prior to imaging
False
AFTER
What is the most common indication for nasal planum resection?
Neoplasia
- SCC
- Lymphoma, maligant histiocytosis, maligant melanoma, basal cell carconoma, mast cell tumor , HAS
What type of surgery would you do to gain access to the nasal cavity and sinuses?
Rhinotomy (dorsal)
What type of surgery would you do to access the ventral nasal cavity and choanae?
Rhinotomy (ventral)
You have a dog with a sinusitis and you want to drain and infiltrate drugs into the cavity. What type of surgery would you do?
Sinusotomy
What are the major risks and complications of nasal surgery?
Hemorrhage —> dorsal, lateral, and major palatine arteries
Flap necrosis
Oronasal fistula (surgically made passage between the oral and nasal cavity)
Dehiscence
Stenosis of the airway
Incomplete resection or recurrence (neoplasia)
Brachycephalic breeds have a local chrondrodysplasia that results due to early ankylosis of what bones?
Basioccipital
Basisphenoid
What are the brachycephalic dog breeds?
English and French bulldog Pug Shih Tzu Pekingese Boston Terrier Boxer
Chihuahua Cavalier King Charles spaniel Maltese Chow chow Yorkshire terrier Miniature pinscher Shar pei
What are the primary disease components of brachycephalic airway syndrome?
Stenotic nares
Elongated soft palate most important
Everted laryngeal saccules/stage I laryngeal collapse
Hypoplasia trachea
What are some contributing problems to brachycephalic airway syndrome?
Nasopharyngeal turbinates Stage 2/3 laryngeal collapse Tonsillar eversion Tracheal collapse Secondary edema Macroglossia
What is the pathophysiology of upper airway obstructive disease?
Higher neg pressures to overcome obstruction —> secondary soft tissue changes (edema/hyperplasia/collapse) —> decreased air flow with increased obstruction
Normally, the epiglottis should overlap the soft palate by how much?
1-2mm at midline
Elongated soft palate causes what respiratory sound/sign??
Inspiratory dyspnea (Stertor)
Exentsion of the soft palate into the rima glottis causes obstruction and causes loss of protective laryngeal function
Stage the laryngeal collapse..
Collapse of the cuneiform cartilage
Stage 2
Stage the laryngeal collapse..
Everted laryngeal saccules
Stage 1
Stage the laryngeal collapse ..
Collapse of the coriculate cartilage
Stage 3
Collapse of the larynx results in what respiratory sound?
Stridor
What is a hypoplasic trachea?
Irregular, thick/firm cartilage rings
Overlap of rings
Increased airflow resistance
T/F: Hypoplastic trachea can be treated by placing a tracheal stent
False
No treatment
What gastrointestinal comorbidities are seen with BAS?
Regurgitation Vomiting Hiatal hernia Pyloric hypertrophy Ulceration
Risk factor for aspiration pneumonia
Signalment associated with BAS?
Brachycephalic
2-3yrs
M>F
What is your DDX for chow chow that presents as..
Exercise intolerance
Increased noise, “snoring”, or “snuffling”
Gastrointestinal signs
Brachycephalic airway syndrome
Space occupying mass of the upper airway
- neoplasia
- abscess
- granuloma
- foreign body
- epiglottic retroversion
What would you look for on radiographs on a dog with BAS?
Right heart enlargement
Assess for hypoplastic trachea (tracheal lumen:thoracic inlet ratio)
Non-cardiogenic pulmonary edema
Aspiration pneumonia
Hiatal hernia
Megaesophagus (may be associated with reflex of esophagitis)
How should you perform an upper airway exam for BAS ?
Avoid drugs that affect laryngeal function
(Eg ketamine, diazepam, large dose pure u, or acepromazine)
Propofol, then can give sedative/opioid after exam
Doxapram improve respiration (general CNS stimulant )
Tonsil -> soft palate -> nasopharynx -> arytenoid cartilages -> nares
When is surgery necessary for BAS?
When there is presence of any of the components
-early surgical intervention is important to prevent secondary changes
You just did surgery on a BAS patient.. what should you do post op?
GU protectants and promotility agents (eg famotidine, pantoprazole, metoclopramide)
Anti-inflammatories for soft palate reaction and saccule excision
Anti-emetic at time of pre-med (maripotant)
Preoxygenation
What are techniques that can be used in a staphylectomy?
Sharp dissection (freehand/ “cut and sew”)
CO2 laser excision
Bipolar sealing device excision
What are the advantages to doing a staphylectomy with a laser?
Rapid
Very little blood loss
What technique is useful for soft palate surgery when the palate is very thick?
Folded flap palatoplasty
—> excision of part of the oropharyngeal soft palate and underlying muscle
—> nasopharyngeal side folded forward and sutured to the orophargyneal border resulting in both shortening and thinning of the palate
What are common complications to staphylectomy?
Acute
- hemorrhage and inflammation
Chronic
-undershortening
Overshortened —> nasal reflux and aspiration
What is the surgery done to correct everted laryngeal saccules ?
Excision
—> cut with scissors and left to heal by second intention
What are methods that can be used to correct stenotic nares?
Wedge resection (horizontal/vertical/dorsolatera)
Amputation - alar wing +/- alar fold
Alapexy
What is the surgery to correct a stage II laryngeal collapse??
Partial arytenoidectomy and ventriculochordectomy
What complications can arise from an arytenoidectomy and ventriculochrordectomy?
“Webbing” or stricture
-> can be avoided by NOT cutting to the ventral and dorsal extends of the corniculate processes and vocal folds
What is the surgical corrections for a stage 3 laryngeal collapse?
Permanent tracheostomy
This is an end stage processes —> salvage procedure
post-op care for BAS patient?
\+/- nasal O2 Avoid overheating (decrease panting and labored breathing)
Leave intubate as long as possible
Sternal recumbency with head up
Analgesia - buprenorphine
+/- sedation
Anti-inflammatory
NPO for 24hours
Treatment of GI signs
E-collar
What is the medical treatment for BAS?
Weight loss Environmental changes -cool -decreased activity -reduce exposure to respiratory irritants
Harness
Treat underlying GI disease
What is the outcome for correction of any component of BAS?
Success rate 61-95%
Will not resolve snoring
Mortality 3-6% - English bulldogs secondary to aspiration pneumonia
Laxity of the hypepiglotticus muscle in the face of extreme inspiratory effort can lead to??
Epiglottic retroversion
What is the treatment for epiglottic retroversion?
Surgical pexy of the ventral aspect of the epiglottis and the dorsal base of the tongue
What muscle is responsible for laryngeal abduction?
Crycoarytenoidus dorsalis
What nerves innervate the muscles of the larynx?
Cranial (sensory) and caudal (motor) laryngeal nerves
-> vagus nerve
—> cranial laryngeal
—> recurrent laryngeal —> caudal laryngeal
What are the diseases of the larynx?
Paralysis
Collapse
Neoplasia Cyst Trauma Foreign bodies Laryngeal web formation
What are the clinical signs of laryngeal dz?
Stridor Exercise intolerance Gagging/dysphagia Dysphoria Coughing
Dyspnea that does not improve with open mouth breathing
Etiology of largyneal paralysis ?
Dysfuntion/damage to vagus and branches
- acquired vs congenital
- unilateral vs bilateral
Congenital largyneal paralysis is seen in what breeds??
Bouvier de Flanders, huskies, bull terriers, and Dalmatians
—> progressive nerve degeneration
Rottweilers
—> progressive generalized degenerative disease
—> ataxia, paresis, head tremors, neurogenic muscle atrophy
Signalment of acquired laryngeal paralysis?
Large breed, older dog
Poster children are the overconditioned labs and retrievers
What is the cause of acquired laryngeal paralysis ??
Part of a generalized neuropathy
—geriatric onset largyneal paralysis polyneuropathy (GOLPP)
Idiopathic is most common Hypothyroid Trauma Immune mediated (myasthenia gravis) Infectious Toxin (lead or OP)
What should you be looking for on radiographs of a dog with suspected laryngeal paralysis ?
Thoracic rads
- Aspiration pneumonia
- Megaesophagus
- Cranial mediastinal masses (thymoma)
- Non cardiogenic pulmonary edema
Cervical rads
- laryngeal cartilages
- masses
In what case would an acetylcholine receptor antibody titer help to diagnose largyneal paralysis?
Thymoma associated with myasthenia gravis
What is the treatment for laryngeal paralysis??
unilateral arytenoid lateralization
(THE ONLY TREATMENT) —> decrease airway resistance
Medical
-> weight loss, stress reduction, exercise restriction, environmental changes
Post-op care for arytenoid lateralization?
Maintain ET tube until patient sufficiently awake
Avoid heavy sedation or meds that may cause nausea/vomiting
NPO for 24hrs - small amount of water and food with close monitoring
Monitor for signs of aspiration pneumonia
What is the most important complication of unilateral arytenoid lateralization ??
Aspiration pneumonia
LIFE long risk
Devocalization surgery is AKA?
Ventriculocordectomy
In a ventricuocordectomy, it is important to leave 1-2mm ventral cord intact. Why?
To decrease risk of webbing
