Mouth and upper resp tract Flashcards
(41 cards)
Primary Complaints with mouth and upper resp tract
A. Respiratory Noise &/or exercise intolerance
B. Nasal Discharge
1. Purulent
2. Bloody
3. Food material
C. Difficulty eating &/or swallowing
D. Asymmetry of head or cranial neck
clinical exam for nasal discharge should look at what?
- Character of discharge
- Unilateral vs bilateral (differentials for both)
- Malodorous or not
how to assess airflow at clinical exam?
Compare both flow at the nostrils
history we should take for resp problem
- Duration
- Performance
- Respiratory noise, when, what type and how?
clinical exam for mouth and upper resp tract - what to look for?
- Head or neck deformation?
- Palpation and sinus percussion
- Examine teeth and oral cavity
- Evaluation at rest and exercise if hx of respiratory noise or intolerance
> at expiration and/or insiration?
> characterize the noise
> progressive vs sudden
endoscopy - when should we not sedate? principles?
- Do not sedate if evaluating function of larynx, pharynx….
> might collapse the upper airway structure - do both sides
- may need to evaluate after exercise, or better is dynamic endoscopy
radiology can be used to evaluate what structures for mouth and resp tract?
- Nasal cavity, sinuses and upper teeth
- Lower mandible and teeth
- Pharynx, larynx, guttural pouches
- Upper neck
what would be abnormal in a radiograph?
- increased (Fluid, soft tissue or mineralized tissue) or decreased (osteomyelitis, bone lysis, fx) density, or abnormal position
Respiratory Noise &/or Exercise Intolerance
- main issues that cause this
- Laryngeal Hemiplegia
- Epiglottic Entrapment by Aryepiglottic Fold
- Dorsal Displacement of the soft palate
- Pharyngeal Lymphoid Hyperplasia
- Other conditions: arytenoid chondritis, axial deviation of the aryepiglottic fold, subepiglottic cyst
…
Respiratory Noise &/or Exercise Intolerance
- when is ti an emergency?
- if present at rest! probably a severe obstruction, probably needs to be referred
Respiratory Noise &/or Exercise Intolerance
- if it is exersize related, what questions should we investigate?
a. Consistent?
b. Intermittent?
c. Related to type of exercise?
d. Head position?
e. Fatigue?
Respiratory Noise &/or Exercise Intolerance
- what diagnostic technique should we employ?
endoscopy
why does the soft palate need to be under the epiglottis in a horse?
because horses are solely nose breathers
what muscle makes the arytenoid open up?
- function
- innervation
cricoarytenoideus dorsalis muscle
> if it is dysfunctional, we have impaired airflow
<><>
the only abductor of arytenoid cartilage(s)
(1) Innervated by recurrent laryngeal nerve (RLN) (branch of vagus nerve)
(2) No crossover innervation between left & right sides
Laryngeal Function
(1) Passage for air from nasopharynx to trachea
(2) Must also stop food & water from entering trachea
(3) Therefore, must expand (abduct arytenoids) during exercise & close (adduct arytenoids) during swallowing
laryngeal hemiplasia
- who gets this?
- which sides?
- pathogenesis?
- genetic predisposition for Thb & draft horses
- most common is left sided paralysis (98%) > left sided nerve travels more superficially and is prone to trauma
<><><><> - Result from progressive loss of nerve fibers in left recurrent laryngeal nerve -> atrophy of muscle cricoarytenoideus dorsalis -> loss of abductor function
- damage to nerve may be secondary to local trauma (thrombophlebitis, neurological disease…)
- Loss of abduction result in:
> collapse of left arytenoid during inspiration
> saccule in vocal folds protrusion in airway
> increased inspiratory resistance and pressure
> turbulence and decrease airflow
> noise and exercise intolerance
Causes of RLN damage
(1) Usually idiopathic neuropathy that affects left side of larynx (microscopically, both left & right RLN often affected)
(2) Also due to trauma, extravascular injections, guttural-pouch infection, &
Strep-equi-equi infection
Laryngeal Hemiplegia clinical signs
- Exercise intolerance
- resp noise at inspiration (roaring or whistling sound) - progressive
- resp distress
Dx for larygeal hemiplegia
- history, palpation, endoscopy
Laryngeal Hemiplegia treatment
- when do we need it?
- what are our options?
- Only necessary if causing exercise intolerance (may not be needed for lower-level performance horses or pleasure horses)
- Sometimes treatment aimed more at eliminating noise (hunters, show horses)
<><><><><> - Ventriculectomy (excise ventricle lining/saccule) ± cordectomy (excise vocal fold/cord)
> subsequent scar tissue abducts vocal fold, may help prevent collapse of arytenoid cartilage into airway
<><> - Prosthetic laryngoplasty (“tie-back”) > dont tie too tight or food can get into resp tract (tie at 60-70 degrees)
> Often indicated in performance horses with exercise intolerance
> Suture(s) placed to abduct the arytenoid cartilage (mimics cricoarytenoideus dorsalis muscle between cricoid cartilage & muscular process of arytenoid cartilage)
> Often performed in combination with ventriculectomy (ventriculectomy may help eliminate noise), but airway resistance studies question additional benefit of ventriculectomy
<><> - arytenoidectomy
<><> - neuromuscular pedicle graft > this takes time to regenerate, not wanted for racehorses in many cases
Chondritis of arytenoid
- what is this?
- clinical signs?
- treatment?
- Inflammatory disease +/- infection
<><> - Clinical Signs:
- Same as laryngeal hemiplegia
- Sometimes more severe
<><>
Treatment: - Conservative
- arytenoidectomy
- may have to do tracheotomy in emergency
how can we differentiate chondritis of arytenoid from laryngeal hemiplagia?
- chondritis will look thickened, may see discharge and pus
Granuloma (chondroma) of larynx / arytenoid
- what is it?
- clinical signs?
- treatment?
- Mass projecting from medial surface of corniculate process of arytenoid.
- clinical signs:
> Coughing
> Exercise intolerance
> Respiratory noise - treatment > ablation
Epiglottic entrapment:
- what is this?
- Entrapment by the aryepiglottic folds
- Occurs when that membrane located ventrally becomes dorsally displaced.
- May be intermittent or permanent