Exam 2: Lecture 11 - Laryngeal Paralysis Flashcards
What is defined as the complete or partial failure or the arytenoid cartilages and vocal fods to abduct during inspiration
laryngeal paralysis
What is number 1
Corniculate process
What is number 2
Cuniform process
What is number 3
Cuniform cartilage
What is number 4
Corniculate cartilage
What is number 5
Arytenoid cartilage
The intrinsic muscle of the dogs larynx are innervated by somatic efferent axons from which nerve?
Vagus nerve
Some axons leave the vagus in which nerve to innervate the cricothryoid muscle; others provide sensory innervation to the mucosa
Cranial laryngeal nerve
Which nerve, a branch of the vagus nerve terminates as the caudal laryngeal nerve, which innervates the remaining intrinsic muscles of the larynx
recurrent laryngeal nerve
Which nerve traveks along the dorsolateral surface of the trachea and continues over the lateral surface of the cricoarytenoids dorsalis before deviating to the medial surface of the thyroid cartilage laminate
caudal laryngeal nerve
The following can cause?
- Dysfunction of laryngeal muscles
- Dysfunction of recurrent laryngeal or vagus nerve
- Cricoarytenoid ankylosis
Upper respiratory obstruction and mild to severe dyspnea
What are the most common causes of upper respiratory obstruction and mild to severe dyspnea
acquired or congenital neurological causes are the most common
Atrophy of the cricoarytenoid dorsalis muscle causes the cartilages to remin in a paramedian position during inspiration, preventing maximal air intake and increasing airflow resistance. the narrowed rima glottidis increases resistance to airlfow and creates turbulence, which gives rise to which condition?
Laryngeal Stridor
To maintain the same flow rate through the paralyzed larynx as is seen in the remainder of the respiratory tract, the speed of airflow through the larynx must increase or decrease?
increase
Congenital, inherited laryngeal paralysis occurs in which breed of dogs?
- White coat german shepherd dogs
- Bouvier des flandres
- Bull terriers
- Siberian Huskies
A congenital laryngeal paralysis polyneuropathy complex associated with dying back of peripheral nerves has been recognized in which breed of dogs?
- Dalmatians
- Rottweilers
- Leonberger Dogs
- Pyrenean Mountain Dogs (Great Pyrenees)
Acquired laryngeal paralysis is caused by damage to the recurrent lryngeal nerve or intrinsic laryngeal muscles is most often attributed to?
- Polyneuropathy
- Polymyopathy
- Accidental or Iatrogenic Trauma
- Intrathoracic or extrathoracic masses
- Many other causes have been proposed
The Abbreviation ______ has been proposed as more accurate term for dogs with acquired laryngeal paralysis where other causes have been ruled out
GOLPP
- geriatric onset laryngeal paralysis polyneuropathy
List the proposed etiologies
What is the signalment of Laryngeal paralysis in dogs
- More common in large breed dogs
- males are affected two to four time more than females
- Dogs with unilateral Laryngeal paralysis rarely symptomatic
Acquired idopathic Laryngeal paralysis is most common in?
middle-ages or older dogs
COngenital Laryngeal paralysis should be suspected in _____ large breed dogs with upper airway obstruction
young
- less than 1 year of age
Which breed is the most commonly reported for Laryngeal paralysis
Labrador Retriever
Over-represnted breeds of Laryngeal paralysis are?
- golden retrievers
- saint bernard
- newfoundlands
- irish setters
- Brittany spaniels
T/F: Laryngeal paralysis is uncommon in cats
true
clinical presentation of Laryngeal paralysis in cats include?
- similar to the dog
- cats with unilateral laryngeal paralysis can present with significant clinical signs
Prevelance of ____-sided unilateral Laryngeal paralysis has been noted in cats, similar to what is reported in human and horses
left-sided
Specific cause of Laryngeal paralysis in cats in unknown. Several cases though have been associated with?
- trauma
- neoplastic invasion
- Iatrogenic damage
Animals with Laryngeal paralysis my frequently have a history of?
- progressive inspiratory stridor
- voice change
- exercise intolerance
Animals with Laryngeal paralysis may also have?
- increased stridor
- dyspnea
- cyanosis
- coughing
- gagging
- vomiting
- restlessness
- anxiety
T/F: Some animals with Laryngeal paralysis are asymptomatic at rest?
true
clinical signs of Laryngeal paralysis may be exacerbated by?
- obesity
- exercise
- excitment
- high ambient temperatures
Laryngeal paralysis occurs in approximately ____ of dogs with tracheal collapse
one-third
All animals with Laryngeal paralysis are at risk for?
aspiration of food and saliva
PE findings of animals with Laryngeal paralysis include?
- exam findings are nonspecific
- Labored breathing
- Continuous panting
- Hyperthermia
- Muscle wasting
- Weakness
- Other neurological signs
T/F: Laryngeal paralysis can be diagnosed radiographically
false, it can NOT
which technique can be used to evaluate Laryngeal paralysis
ultrasound
Lateral cervical and thoracic radiographs can cause what 3 issues in animals with Laryngeal paralysis?
- R/O other causes of respiratory noise
- Post-obstruction pulmonary edema
- Aspiration pneumonia
Warning‼️
- Corrective surgery in dogs with proximal esophageal dysfunction may result in?
devastating/life-threatening aspiration
- survey radiographs is rarley adequate
It is critical to assess the preoperative esophageal function _______
preoperatively
T/F: Even dogs with substantial esophageal dysfunction may have no evidence of esophgeal dilation and no H/O regurgitation
true
Contrast barium esophagrams using fluoroscopy may be performed in dgos with clinical signs of esophageal dysfunction. The benefit of this procedure must be weight against the risk of?
Aspiration
T/F: Animals require a light general anesthesia for a laryngoscopy?
true
Laryngeal motion must be compared with the phase of _______ for interpretation
respiration
_________ for laryngoscopy should be delayed to facilitate examination
intubation
A normal larynx maximally abducts during inspiration or expiration
inspiration
In affected dogs, the laryngeal cartilages are loacted in which position and do not abduct during inspiration
paramedian
T/F: During a laryngoscopy paradoxal vocal fold movement may occur?
true
Fluttering of the vocal folds and arytenoid cartilages must not be mistaken for ?
purposeful abduction
What does the image on the left show?
Unilateral paralysis
What does the image on the right show?
Bilateral paralysis
What labatory findings are usually normal for Laryngeal paralysis
hematologic and serum biochemistry
Additional diagnostics for Laryngeal paralysis can be?
- eletromyography of laryngeal muscles
- nerve conduction velocity
- nerve biopsy
Differential diagnosis of Laryngeal paralysis may include?
- brachycephalic syndrome
- laryngeal collapse
- tracheal collapse
- masses
- airway trauma
Which type of dogs often require no treatment if they maintain a sedentary lifestyle and avoid excessive weight gain and stress
Midly affected dogs
Exercise restriction and elimination of percipating causes may be beneficial when clinical signs are _____ with Laryngeal paralysis
mild
Which type of dogs are more successfully managed with medical therapy then large dogs
small dogs
Initial treatment of acute respiratory distress is directed at?
- improved ventilation
- reducing laryngeal edema
- minimizing the animals stress
Typical treatment of animals with acute respiratory distress involves?
- oxygen supplementation
- Short-acting glucocorticoids
- sedatives
- Buprenorphine or butorphanol also may be considered
T/F: Appropriate cooling procedures instituted if hyperthermic. Intubation or a temporary trachestomy should be considered if respiratory distress cannot be _______
abated
Dogs that received a temporary trachestomy preoperatively were more likely to expierence?
Major complications
Drugs used for acute respiratory distress can be?
Perioperative management of respiratory distress includes?
- observed closley before surgery for respiratory distress
- kept cool, calm and quite
- pretreat with anti-inflammatory dose of glucocorticoid immediately before surgery
Define patient positioning for Arytenoid cartilage lateralization
lateral recumbency with neck over a rolled towel and rotated to elevate the ipsilateral mandible
- head my be stabilized by taping it to the table
What are the two surgical treatments for Arytenoid cartilage lateralization
- unilateral arytenoid lateralization
- Permanent trachestomy
What is the treatment of choice for Arytenoid cartilage lateralization
unilateral arytenoid lateralization
Which surgical treatment for Arytenoid cartilage lateralization is considered a salvage procedure for dgos most at risk of aspiration pneumonia, but it is associated with a high rate of major and minor complications and requires diligent posteroperative and long-term care
Permanent tracheostomy
Unilateral arytenoid lateralization is the most common technique for Arytenoid cartilage lateralization. What does this technique involve?
This technique mimics the directional pull of the cricoarytenoid dorsalis muscle and rotates the arytenoid cartilage laterally
suturing the cricoid cartilage to the musclular process of the arytenoid cartilage
Unilateral arytenoid lateralization is also known as?
laryngeal tie-back surgery
Advanced surgical procedures for Arytenoid cartilage lateralization recommend?
Referral
What procedure does this show?
Laryngeal tie-back surgery
What does this image show?
Laryngeal tie-back surgery
What does this image show?
Laryngeal tie-back surgery
What does the following describe?
Laryngeal tie-back surgery
Post-op care and assessment of Laryngeal tie-back surgery includes?
- monitor closely for respiratory distress
- Analgesics as needed
- Gagging and coughing may occur in the early postoperative period. Swallowing discomfort may occur
- Impaired glottic function may persist
- IV fluids maintained until drinking
- Soft food in meatball form may be offered shortly after procedure, but observe for evidence of aspiration
Exercise restriction for 6 to 8 weeks, barking minimized (quite and hoarse) and coughing occurs in most dogs are post-op and assessment for animals with which surgery?
Laryngeal tie-back surgery
Early complications of suture lateralization include?
- hematoma formation
- Swallowing discomfort
- Temporary glottic impairment
- Incisional issue
- coughing after eating or drinking
Complications of suture lateralization usually resolves within a few days unless?
aspiration
The following is a complication of?
- the cartilages of congenitally affected dogs may be insufficiently mineralized to retain sutures
Suture lateralization
The following is a complication on?
- mineralized cartilages of older dogs may fracture or avulse the musclular process, causing failure of abduction and recurrence of clinical signs
Suture lateralization
Aspiration pneumonia occurs in what % of dogs
10-20%
Factors associated with high risk of developing aspiration pneumonia include?
- Increasing age
- temporary tracheostomy
- progressive neurologic disease
- postoperative megaesophagus
- esophageal disease
- concurrent neoplasia disease
- postoperative administation of opioids
Prognosis of mild or no clinical signs are rest is?
do well without surgery
Prognosis of animals with moderate to severe clinical signs are?
may develop laryngeal collapse and acute respiratory obstruction
Prognosis after unilateral lateralization is?
good
- over 90% of patients have less respiratory distress and improved exercise tolerance
What is defined as the creation of a stoma in the ventral tracheal wall by suturing tracheal mucosa
- maintained for life or until the stoma is surgically closed
Permanent tracheostomy
What procedure is recommended for animals with upper respiratory obstruction causing moderate to severe respiratory distress that cannot be successfully treated by other methods
Permanent tracheostomy
What does this image show?
Permanent tracheostomy
What is shown in this image?
Permanent tracheostomy
With a Permanent tracheostomy owners should we warned of?
- must be restricted from swimming
- vocilization is diminished or absent
- increased risk for respiratory infections
- ongoing care of the site will be necessary to keep it clean
The following are key points of?
- etiology of laryngeal paralysis
- unilateral arytenoid lateralization is the treatment of choice
- most common complication is aspiration pneumona
- Permanent tracheostomy is best for cases that are high-risk for aspiration pneumonia
Laryngeal paralysis
Good to know these key points