Foundation Equine Upper Airway Flashcards
where is the greatest flow resistance?
nasal passages
larynx
what is airway resistance mainly determined by?
airway diameter
what is the pharynx composed of?
nasopharynx
oropharynx
laryngopharynx
what is the havemeyer grading scale for?
upper airway function: arytenoid and larynx movement
how common is dorsal displacement of the soft palate?
10-20% of 2-3 year old racehorses
what is the best surgical treatment for dorsal displacement of the soft palate?
correct anatomical abnormalities and tie-forward with partial bilateral resection of sternothyroideus tendon/muscle
what is staphylectomy?
partial soft palate resection
what is a standard myectomy?
partial transection of sternohyoideus and sternothyroideus
what is the goal of a laryngeal tie-forward?
replace action of thyroideus muscle by sutures placed between thyroid cartilage and basihyoid bone
what is the epiglottis entrapped in with epiglottic entrapment?
aryepiglottic fold
what are the clinical signs of epiglottic entrapment?
exercise intolerance
inspiratory noise
what happens in recurrent laryngeal neuropathy?
muscle paralysis from progressive loss of large myelinated axons
what are the clinical signs of recurrent laryngeal neuropathy?
inspiratory noise
exercise intolerance
what is the most common etiology of recurrent laryngeal neuropathy?
unknown
which head positions increase inspiratory impedance?
flexed head and neck positions
what do muscles extrinsic to the nasopharynx affect?
position of basihyoid bone and/or larynx
probably morphology of nasopharynx by changes to oropharynx
what are the options for the havemeyer grading scale?
grade I
grade II
grade III
grade IV
what are the clinical signs of dorsal displacement of the soft palate?
exercise intolerance
expiratory noise
bruising of roof of nasopharynx
open-mouth breathing
what is the medical treatment for dorsal displacement of the soft palate?
dexamethasone
topical anti-inflammatory solution
condition if unfit
tack changes to elevate head
figure of 8 nose band or tongue-tie
what is an indication for a staphylectomy for dorsal displacement of the soft palate?
granuloma or mass at free edge of soft palate or after tie-forward
what is an indication for laser staphylectomy for dorsal displacement of the soft palate?
after tie-forward to permit epiglottis to be repositioned dorsal to soft palate after swallowing
what is the goal of a standard myectomy?
reduce caudal retraction of larynx
what is the epiglottis entrapped in in epiglottic entrapment?
aryepiglottic fold
what is the post-operative plan for epiglottic entrapment?
anti-inflammatories
dexamethasone
topical pharyngeal spray
rest for 4 weeks
which muscle abducts the arytenoid?
cricoarytenoideus dorsalis
what does a prosthetic laryngoplasty do?
maintains affected arytenoid in open and fixed position
for recurrent laryngeal neuropathy
what does a ventriculocordectomy do for recurrent laryngeal neuropathy?
removes cord/saccule of affected side
what are the chronic complications of recurrent laryngeal neuropathy?
persistent coughing
chronic airway contamination/inflammation and infection
suture pullout, progressive loss abduction
what is larygneal reinnervation in recurrent laryngeal neuropathy?
nerve-implantation into affected cricoarytenoid dorsalis muscle
