Laryngeal Paralysis Flashcards
(34 cards)
what are the 4 cartilages of the larynx?
- epiglottic
- arytenoid
- thyroid
- cricoid
what nerve is most important associated with the larynx and innervates the cricoarytenoid muscle?
recurrent laryngeal nerve
this nerve originates from the vagus nerve
what muscle is most important that is associated with the larynx?
cricoarytenoideus dorsalis muscle
dilates the glottic cavity by abducting the vocal folds
why is the larynx important?
- prevents aspiration
- controls airway resistance
- voice production
Which of the following statements is FALSE about laryngeal paraylsis?
A. can occur due to injury to the cricoarytenoideus nerve
B. can be unilateral or bilateral
C. can be congenital or acquired
D. occurs in dogs and cats
E. occurs in male dogs more frequently than female
A. can occur due to injury to the cricoarytenoideus nerve
It occurs due to injury/damage to the vagus or recurrent laryngeal nerves
What 4 breeds are at risk for CONGENITAL laryngeal paralysis that is manifested in dogs <1 yo?
- bouvier des flandres
- dalmatians
- huskies
- rottweilers
these animals usually have a concurrent progressive neurologic degeneration
which 4 breeds are at risk for ACQUIRED laryngeal paralysis?
- labrador retrievers*
- golden retrievers
- st. bernards
- irish setters
the acquired form has an onset of avg 9 years of age.
What are the 5 potential causes of acquired laryngeal paralysis?
- idiopathic (often accompanied by a generalized polyneuropathy, talk to client about this)** most commonly
- neoplasia (thyroid tumor, mediastinal mass – invasive into nerve)
- endocrine polyneuropathy (hypothyroidism association)
- immune-mediated polyneuropathy (immune-med destruction of nervous system)
- iatrogenic (in surgery, cut RLN)
What are the clinical signs of laryngeal paralysis?
EARLY on: voice changes, gagging, coughing with food and water intake
LATER on: exercise intolerance, inspiratory stridor, acute respiratory distress secondary to exacerbation of disease (warm temps –> heat stroke)
T/F: progression of laryngeal paralysis is fairly quick
false - slow
what diagnostics should you run on a dog that presents to your clinic with inspiratory stridor, gagging, coughing, and exercise intolerance?
- CBC/Chem/UA
- T4, TSH
- thoracic + cervical xrays
- esophagram / swallow studies
T/F: dogs with laryngeal paralysis are at risk for aspiration pneumonia
true
because they cannot control their airway well. Radiographs are a great way to screen for causes of LP like masses, but also can check for aspiration pneumonia. 7.9% dogs with LP have aspiration pneumonia. You should take radiographs prior to surgery and DELAY the surgery if detect asp. pneumonia because anesthesia increases risks.
AFTER surgical correction of LP, there is a 21% risk of developing asp. pneumonia.
What medications should you avoid in your anesthesia protocol for a patient with laryngeal paralysis?
medications that cause panting (hydromorphone)
What type of things are you looking for during your laryngeal exam?
- masses
- Soft palate appearance
- edema, erythema
- arytenoids, vocal folds abducting during inspiration
- match timing of inspiration with arytenoid motion
How would you handle an emergent case of laryngeal paralysis?
- cooling (if temps >105)
- supplemental oxygen
- IV sedation (ace, butorphanol) calms patient down
- IV corticosteroids (dexamethasone)
- cautious fluid therapy
- intubate (if severe)
- temporary tracheostomy (very severe cases)
T/F: some patients with laryngeal paralysis can be managed without surgery
true
if they are asymptomatic AT REST, then you could recommend things such as weight loss, stress reduction, exercise restriction, avoiding hot temps.
however, you must inform the client that this is a progressive disease and surgery is the treatment of choice in most cases.
what is the GOAL of surgery to correct laryngeal paralysis?
decrease airway resistance
what surgeries are available for the treatment of laryngeal paralysis?
- arytenoid lateralization (standard technique, unilateral lateralization of one of the arytenoids tying it to the cricoid cartilage or thyroid cartilage)
Other/Salvage options:
2. ventricular cordectomy, partial arytenoidectomy
3. modified castellated laryngofissure
4. permanent tracheostomy (salvage)
what is the standard surgical APPROACH to laryngeal paralysis correction?
left lateral cervical approach
the incision should be parallel and ventral to the jugular vein
how big do you want to make the glottic opening when surgically correcting laryngeal paralysis?
no larger than ET tube
what are potential complications of surgical correction of laryngeal paralysis?
- aspiration pneumonia
- persistent clinical signs (cough, gag, stridor)
- suture failure
- cartilage fracture
T/F: bilateral arytenoid lateralization is preffered over unilateral
false unilateral is preffered.
what are signs of feline laryngeal paralysis?
- tachypnea
- dyspnea
- dysphonia
- dysphagia
- anorexia
- cough
- weight loss
feline LP is not as common as canine
What drug can we pre-treat patients with if we want to decrease risk of developing aspiration pneumonia?
metoclopromide – increases GI motility and decreases risk of regurg and aspiration.
