10-12. upper respiratory sx 1-3

symptoms of upper airway disease

• sneezing/nasal discharge — nasal cavity

• coughing — tracheal / bronchial disease

• noisy breathing — turbulent airflow

  • stertor (nasal cavity / pharynx)

  • stridor (larynx / trachea)

• dyspnea — inspiratory (extrathoracic) vs. expiratory (intrathoracic)

nasal cavity symptoms

• sneezing

• nasal discharge

• epistaxis

• ocular discharge (nasolacrimal duct)

• facial deformity

• exophthalmos

nasal cavity diagnostic imaging

• radiography

  • open mouth VD; obliques; rostrocaudal (frontal sinuses)

  • increased density

  • bone loss

  • doesn’t demonstrate extent of disease

• CT

  • helps localize disease

  • determines limits

  • evaluate cribiform plate

• rhinoscopy / nasopharyngoscopy

indications for rhinotomy

• diagnosis (other tests fail to answer)

• infection (aspergillus) — medical management fails

• neoplasia (adenocarcinoma) — if radiation fails or not an option (cost or availability)

• retrieve foreign bodies (failed rinoscopy)

rhinotomy complications

• acute

  • hemorrhage

  • subcutaneous emphysema

• chronic

  • recurrent infection

• failure to identify / recurrence of disease

  • combination tx recommended for neoplasia / fungal disease

nasal adenocarcinoma treatment

• radiation = first line therapy

• average age > 10 years (follow-up surgery rarely indicated)

nasal aspergillosis clinical signs

• nasal discharge / pain

• planum ulceration / depigmentation

• sneezing / epistaxis

nasal aspergillosis diagnostics

• imaging — radiographs / CT (turbinate destruction)

• rhinoscopy / sinuscopy — fungal plaques

• cytology / histopathology — squash preps better than swabs

• fungal culture

• serology unreliable

when is rhinotomy indicated for nasal aspergillosis?

• cases refractory to topical treatment

• heavy sinus involvement

• cribriform plate involvement (topical tx contraindicated due to brain exposure)

• diagnosis uncertain

components of brachycephalic airway syndrome

• stenotic (small) nares

• elongated soft palate

• hypoplastic trachea — small diameter (NOT collapsed)

• redundant pharyngeal tissue

• aberrant nasal turbinates

physiology & secondary complications of brachycephalic airway syndrome

physiology

• abnormal anatomy = turbulent airflow

• increased negative inspiratory pressure causes secondary complications

secondary complications

• everted laryngeal saccules

• laryngeal collapse

• esophageal, gastric, and intestinal inflammation

indications for surgical treatment of brachycephalic airway syndrome

• brachycephalic patient

• stertorous breathing

• exercise intolerance

• worsening of clinical signs / failed medical management

• acute respiratory crisis

brachycephalic airway syndrome — diagnostic work-up & treatment

• stabilize first (oxygen, cool temp, anxiolytic medication)

• thoracic radiographs (examine trachea, rule out aspiration pneumonia)

• sedated oral examination (should immediately precede surgery)

brachycephalic airway syndrome surgical treatments

fixable problems

• stenotic nares → rhinoplasty (resect nares)

• elongated soft palate → staphylectomy (shorten palate)

• everted saccules → excise

• resect excess pharyngeal tissue

salvage procedures

• temporary or permanent tracheostomy

resection of the soft palate

• use caudal extent of tonsillar crypt

• place stay sutures to define the excision

• avoid cautery (can contribute to post-op airway swelling)

• laser is acceptable method; protect ET tube

resection of soft palate — closure

• rapidly absorbable suture

  • 4-0 biosyn, monocryl, or vicryl

• close dorsal nasal mucosa to ventral oral mucosa

• simple continuous

primary vs. secondary cleft palate

• primary: premaxilla and lip

  • unilateral or bilateral (left unilateral more common)

• secondary: hard and/or soft palate

  • hard palate — usually midline

  • soft palate — midline or unilateral

cleft palate pathogenesis

• primary: maxillary process fails to fuse with medial nasal process

• secondary: failed fusion of palatine shelves

• brachycephalics at high risk

• intrauterine insult at specific time (25th-28th day of gestation in dogs)

clinical signs of primary cleft palate

• visual inspection

• difficulty nursing

clinical signs of secondary cleft palate

• nasal discharge / milk

• sneezing

• coughing / gagging with eating

• visual inspection

• aspiration pneumonia

• poor weight gain

at what age is cleft palate repair surgery perfomed?

3-4 months of age

• prior to 2 months, tissue friable

• defect may widen with age

• excise problem teeth 6-8 wks in advance

goal of primary cleft palate repair

• restore normal lip conformation (predominantly cosmetic procedure)

• underlying defect in premaxillary bone remains

goal of secondary cleft palate repair

separate oral and nasal passage

• repair usually performed using local tissue flaps

• tension free (make flaps 1.5x necessary size)

cleft palate repair complications

• dehiscence common

• multiple surgeries typically required

• consider placing feeding tube to minimize post-op trauma

  • esophagostomy

  • gastrostomy

symptoms of laryngeal paralysis (dogs)

• change in phonation (bark tone)

• coughing

• dysphagia

• inspiratory stridor

• dyspnea / respiratory distress

• exercise intolerance / syncope

laryngeal paralysis — concurrent problems

• dysphagia

• regurgitation

  • hiatal hernia

  • megaesophagus

• aspiration pneumonia

• polyneuropathy

• heat stroke

laryngeal paralysis diagnosis

• signalment & history

• clinical signs

• direct laryngoscopy

  • requires light sedation or anesthesia

    • propofol, ket/diazepam, acepromazine may inhibit arytenoid motion

    • doxapram can be used to stimulate respiration

  • lack of coordinated abduction or paradoxical movement (vocal folds pulled inward as a result of neg. pressure)

laryngeal paralysis emergency treatment

• cool environment

• supplement oxygen

• sedate (mild)

• IV fluids

• IV corticosteroids

• minimally invasive “button” procedure

• intubate and/or tracheostomy

arytenoid lateralization

• treatment of choice for laryngeal paralysis

• fixes arytenoid cartilage in abduction

• unilateral is sufficient

• bilateral associated with higher incidence of aspiration pneumonia & no significant respiratory benefit

arytenoid lateralization post-op care

• minimal sedation

  • maintain cough / swallow reflexes

• withhold food & water until fully alert

• monitor for aspiration pneumonia

  • mild coughing is common / normal

ventriculocordectomy

• same as “debark” procedure

  • does not eliminate sound generation

• not optimal for treatment of laryngeal paralysis

• oral approach — incomplete removal

  • maintain ventral commissure (avoid “webbing”)

• ventral approach — required laryngeal incision

  • remove vocalis muscle

  • shift local mucosa & suture defect closed

  • fewer complications

laryngeal neoplasia biological behavior

• locally invasive / can metastasize

• rare differential for laryngeal disease (paralysis more common)

  • several types in dogs

  • lymphoma / SCC most common in cats

laryngeal neoplasia diagnostics

• oral exam, CT scan, cytology / histopathology

• thoracic rads to rule out mets / pneumonia

laryngeal neoplasia treatment

• chemotherapy / radiation — poor response unless lymphoma

• partial laryngectomy

  • defects repaired by flaps and free grafts

• total laryngectomy

  • permanent tracheostomy required

tracheal collapse — medical management

• first line tx

• avoid stress, weight management, cough control, tx infections, cool environment, walk with harness etc.

tracheal collapse — surgical treatment

salvage procedures

• application of extra-luminal rings

  • must preserve blood supply & recurrent laryngeal nerve

  • can only place in cervical trachea

• intra-luminal stents

  • appropriate for thoracic trachea & diffuse collapse

  • can see complications within ~1 yr due to cycling of stent

tracheal foreign body treatment

• endoscopic retrieval preferred (minimally invasive)

• thoracotomy — approach depends on location

  • identify location of foreign body pre-op

  • palpate airway to confirm location

causes of tracheal perforation / rupture

• endotracheal tube injury

• blunt trauma (cats)

• perforating injuries

  • dog bites, projectiles, sticks

  • ddx: pharynx or esophageal penetrating wound

tracheal perforation / rupture treatment

• small leaks typically seal spontaneously

• debridement & closure of larger wounds

• resection/anastomosis = worst case scenario

tracheal stenosis causes & treatment options

• secondary to trauma or surgery

• tx:

  • bougienage or balloon dilation

  • stent placement

  • resection and anastomosis

tracheal resection / anastomosis indications

• tracheal stenosis

• significant acute trauma

• neoplasia

• resection limited by tension on suture line

  • tension = stenosis (granulation tissue)

when is a temporary tracheostomy used? where is it placed?

• emergency management of upper respiratory obstruction

  • larynx / pharynx / proximal trachea

• not useful for pulmonary disease unless with ventilation to maintain patient in more alert status

• may be planned as part of extensive oral or upper resp. surgery

• placement = mid-cervical trachea

  • avoid proximity to larynx or thoracic inlet

temporary tracheostomy techniques

• transverse (horizontal) incision between rings

  • most common; fastest

  • can be easily converted to permanent tracheostomy

• “H” or “I” incision

  • longitudinal through 2-3 rings with transverse incisions between rings at both ends

• “U” shape incision (least preferable)

  • must base cranially

**the transverse part of the incision should not exceed ½ of the tracheal circumference to avoid stricture/stenosis

• stay sutures placed around the tracheal rings cranial & caudal to the tracheostomy facilitate tube placement & cleaning

temporary tracheostomy management

• cold, dry unfiltered air irritates trachea

• increased mucous production

• instill sterile saline (0.2 mLs/kg) q1-4hrs

• clean 4-6 times/day

  • suction (pre-oxygenate before)

  • consider changing tubes every 24-48 hrs

  • soak tubes in 2% chlorhexidine solution & rinse before replacement

removing temporary tracheostomy

• remove tube when no longer needed

  • patient should breathe around tube with tube occluded

• do not close wound in skin or trachea (heal by 2nd intention)

  • have owner gently clean until healed

  • trachea heals without defect

permanent tracheostomy

• salvage procedure for upper airway obstruction

• move trachea to subcutaneous position

permanent tracheostomy complications & long-term management (client education)

• complications

  • tracheitis, stoma obstruction, stenosis/stricture, skin fold obstruction, aspiration pneumonia

• long-term management

  • animal will require close observation

  • clean site at least 2-3 times daily

  • avoid dusty environments

  • no swimming!