Upper Airway Flashcards
when is nasal planum recection used
Nasal Neoplasia - SCC
complete or unilateral removal of the nose
most common complication with nasal planum resection
local recurrence due to imcomplete excision
esp in dogs
what type of suture technique is used to decrease the size of the wound and allow healing by second intention with nasal planum resections
purse-string
complications associated with nasal planum resection
dehiscence - tension on flaps
stenosis
what happened to this dog
Nasal Planectomy and Maxillectomy
common surgical conditions of the nasal cavity
nasopharyngeal stenosis
trauma (i.e gunshot)
neoplasia (adenocarcinoma, SCC, lymphoma, MCT, polyps)
important diagnostic for nasal disease
CT
other diagnostics include: MDB, thoracic rads, sedated oral exam, skull/dental rads, MRI, rhinoscopy, cytology, biopsy, fungal/BacT culture
when should rhinoscopy and nasopharyngoscopy be performed
AFTER imaging
guided or blind biopsies
BacT culture unlikely helpful - PCR for Bartonella and Mycoplasma
types of nasal surgery
Rhinotomy - Dorsal (most common) and Ventral
Sinusotomy
risks and complications of nasal surgery
hemorrhage (dorsal, lateral and major palantine arteries)
flap necrosis
oronasal fistula
dehiscence
stenosis of airway
incomplete resection/local recurrence (neoplasia)
primary components of brachycephalic airway syndrome
elongated soft palate
stenotic nares
shortened, flattened nasal cavity
+/- hypoplastic trachea (can’t fix)
secondary/acquired components of brachycephalic airway syndrome
everted laryngeal saccules/stage I laryngea collapse
pharyngeal/laryngeal mucosal edema
tonsillar eversion
macroglossia
stage II/III laryngeal collapse
tracheal collapse
pathophysiology of upper airway obstructive disease
what is the most common component of brachycephalic airway syndrome
elongated soft pallate
elongated soft pallate results mainly in ______
inspiratory dyspnea - STERTOR!
extension into rima glottidis - severe obstruction, loss of protective laryngeal function
air passage through nasal cavities accounts for _____ of airway resistance
air passage through nasal cavities accounts for 76.5% of airway resistance
stage I largyngeal collapse
everyted laryngeal saccules
stage II laryngeal collapse
collapse of cuniforme cartilage
stage III laryneal collapse
collapse of corniculate cartilage
stage II and III laryngeal collapse results in …
loss of cartilage rigidity - chondromalacia
hypoplastic trachea
irregular, thick/firm cartilage rings
overlap of rings
increased airflow resistance
common in english bulldogs
GI comorbidities with brachycephalic airway syndrome
reguritation
vomitting
hiatal hernias
pyloric hypertrophy
ulceration
why is it important to diagnose GI comorbidites in BAS dogs
can have lesions and clinical signs go undetected by owners
risk factor for aspiration pneumonia in pre and peri-operative peroid
CV changes with BAS
signalment for BAS
~2-3 years (younger in english bulldogs)
M > F
breeds - depends on region of country
mild/moderate BAS clinical presentation
exercise intollerance
increased noise, “snoring,” “snuffing,” reverse sneezing
+/- GI signs
may have mild secondary changes
severe clinical presentation of BAS
present on emergent basis in acute resp distress
+/- heat stroke
+/- GI signs
+/- lower airway disease (non-cardiogenic pulmonary edema, aspiration pneumonia)
likely to have numberous significant secondary changes
DDx of BAS
space occupying mass of upper airway
neoplasia, abscess, granuloma, foreign body, epiglottic retroversion
diagnosis of BAS
upper airway exam under light anesthesia
+ALSO+
thoracic radiographs
+/- lateral cervical views, abdominal rads, blood work
what drugs should be avoided when performing a sedated upper airway exam
ketamine
diazepam (midazolam ?)
large does of pure µ agonist
drugs that affect laryngeal function!!
what drugs can be used in upper airway exam
propofo +/- butorphanol or buprenophine
can utilize doxapram @ 1.1 mg/kg to imporve rate and strength of respiration
use same protocol every time - have a set plan so know how to address complications
possible thoracic radiograph findings with BAS
Rt heart enlargement
assess for hypoplastic trachea (tracheal lumen:thoracic inlet ratio)
non-cardiogenic pulmonary edema
aspiration pneumonia
hiatal hernia
megaesophagus
whats included in the upper airway exam
tonsils
soft palate
arytenoid cartilages (symmetry/evidence of collapse, everted saccules)
additional - laryngeal function, mucosal lesions, excess mucous/saliva, masses
evaluate nares
when is treatment necessary with BAS
presence of any of the components of BAS
- upper airway exam of brachycephalic dogs at time of spay/neuter; early surgical intervention to prevent secondary changes
any animal presenting with clinical signs of BAS
surgical treatment of laryngeal collapse
stage I - excision of everted laryngeal saccules
stage II - above + vocal fold excision, partial arytenoidectomy
stage III - permanent tracheostomy
per-operative considerations for BAS
Gi protectants and promotility agents
anti-inflammatories
anti-emetic at time of pre-medication for anesthesia
pre-oxygenation prior to induction
T/F endotracheal intubation of BAS it is important to ensure cuff is adequately inflated
True
high volume, low pressure - protect trachea
which soft pallate resection technique is easier for novices to perform
clamp (crush) technique
most traumatic
what are some advantages of the laser freehand technique of soft pallate resection
rapid
virtually no blood loss; excellent visualization
minimal post-op inflammation
reduced post-op discomfort
complications of palatectomy
acute: hemorrhage, inflammation
chronic: undershortening (redo), overshortening (nasal reflux, aspiration)
T/F when excising everted laryngeal saccules, small (4-0/5-0) absorbable suture should be used with a double layer closure
False
excise with scissors and let it heal by second intention
complication with arytenoidectomy and ventriculochordectomy
“webbing” or stricture
- avoided by: NOT cutting to the ventral and dorsal extents of the corniculate processes and vocal folds*
- this is also a complication for vocal fold excision for debarking*
what is a salvage procedure for stage III collapse
permanent tracheostomy
considerations: hypoplastic trachea, loose skin folds
why are there so many techniques to correct stenotic nares
severity of collapse
static vs dynamic collpase
cosmetic appearance - least important
techniques for correcting stenotic nares
wedge resection (horizontal, vertical, dorsolateral)
amputation (alar wing +/- alar fold)
alapexy
when can a unilateral arytenoid lateralization be used
only in cases of laryngeal paralysis and if adequate cartilage rigidity is present
medical treatment of BAS
weight loss
environmental changes (cool environment, activity changes, exposure of respiratory irritants)
harness
treat underlying GI disease
should be instituted for every brachycephalic patient!
severe post-operative complications
pharyngeal swelling
vomitting
reguritation
Aspiration pneumonia
T/F there is no single component of BAS associated with pooer outcome
True
treatment of epiglottic retroversion
pexy of ventral aspect of epiglottis and the dorsal base of the tongue
clinical signs of laryngeal disease
respiratory stridor
exercise intollerance
gagging/dysphagia
dysphonia
coughing
dyspnea that does not improve with open mouth breathing
T/F rottweilers have onsets of clinical signs with congenital laryngeal paralysis at younger ages that huskies, bull terriers, dalmations and bouvier de flanders
True
rottweilers - 11-13 weeks of age
other breeds - before 1 year
what is the most common cause of acquired laryngeal paralysis
idiopathic
other causes: hypothyroidism, truama, immune mediated (m. gravis), infectious, toxins (lead, organophosphates)
T/F you should be prepaired to proceed immediately with further diagnositics or surgery based on findings of laryngeal exam
True
surgical treatment of laryngeal paralysis
unilateral arytenoid lateralization
what can be used to help acheive appropriate abduction with unilateral arytenoid lateralization
oversized ET tube
careful: excessive tension may increase risk of aspiration pneumonia due to poor wpiglottic coverage of rima glottidis
post op care with unilateral arytenoid lateralization
maintain ET tube until sufficiently awake
avoid heavy sedation/ med that may induce vomitting
NPO 24 hrs post op
monitor for signs of aspiration pneumonia (hyperthermia, C+, dyspnea, increased respiratory effort, arterial and venous blood gas and rads to confirm Dx)
complications associated with unilateral arytenoid lateralization
aspiration pneumonia
recurrent or persistent signs (may require Sx on contralateral side)
seroma, intramural hematoma, coughing, gagging, dysphagia
T/F some phonation ability may persist/return overtime with devocalization (ventriculocordectomy) procedure
True
what type of approach is taken with a ventriculocordectomy
transoral and ventral
why is it important to leave 1-2 mm ventral cord intact with venticulocordectomy
decreases the risk of webbing
