Intro to URT noise Flashcards
(43 cards)
Reasons for treating URT noise
- dyspnoea
- cosmetics (i.e making a noise when exercising can be undesirable)
- poor performance
- other e.g. dysphagia
How can URT noise cause poor performance?
URT causes large portion of resistance in URT
-> decrease in diameter, increased resistance
-> decreased oxygen delivery
Diagnosis
- hx
- examination of URT at rest
- dynamic observation (vary exercise intensities, consider effect of tack)
- static respiratory endoscopy
- overground dynamic endoscopy
- also consider radiography, CT and occasionally US
What effect can tack have?
- can change airway dynamics
- neck ventroflexion in dressage horses
- other countries sports can cause ‘overcheck’ which can change the way the airflow moves through the URT
Anatomy of external nares
- nostril oval at rest -> round at exercise
- alar fold
– separates diverticulum (false nostril) from true nostril
– supports dorsal and lateral nostril
Conditions of external nares
- epidermal inclusion cysts (atheromas)
- redundant alar folds
- lacerations affecting nostrils
Aims of tx for conditions of external nares
- restoration of normal anatomy and good cosmetic effect
Wry nose
- congenital condition
- lateral deviation of the maxilla and nose
- usually euthanised at birth due to compromised welfare -> unable to breathe and swallow correctly
- reconstruction can be complicated and expensive depending on degree of deviation
Anatomy of the nasal passages
Septum
- right and left nasal passage
Dorsal and ventral conchae
- dorsal, middle, ventral and meatus
- large surface area for humidification, temperature regulation and particulate removal
- constriction of blood vessels (sympathetic tone)
Caudal nasal sinuses - anatomy
- ethmoid turbinates: caudal aspect
- paranasal sinuses
– 7 pairs
– both maxillary sinus open into caudal middle meatus via nasomaxillary aperture
Paransal sinuses - anatomy
Caudal group
- caudal maxillary
- dorsal conchal
- ethmoidal
- frontal
- sphenopalatine
Rostral group
- rostral maxillary
- ventral conchal
Septum between caudal and rostral maxillary sinuses (variable location usually 5cm from rostral aspect of facial crest)
Teeth and the paranasal sinuses
Tooth roots of 4th, 5th and 6th cheek teeth lie within the maxillary sinuses
- infection causes sinusitis
Roots of 3rd cheek tooth forms rostral wall of rostral maxillary sinus
- infection may cause sinusitis
Other structures within maxillary sinuses: nasolacrimal canal and infra-orbital canal
Conditions of the nasal passages
Masses
- fungal granuloma
- neoplasia (particularly SCC)
- ethmoid haematoma
Tx
- attempt transendoscopic
What does an ethmoid haematoma look like?
- dark red-purple structure in the ethmoid region
- basically a big blood clot that forms under the mucosa
Sinus surgery indications
- expansive lesions in paranasal sinus e.g. sinus cyst, neoplasia, ethmoid haematoma, tooth tooth abscess
- primary sinusitis
- severe trauma of facial bones
Sinus surgery considerations
- must identify which sinus is affected
- know anatomical landmarks for each region
- consider endoscopic/laser surgery options 1st as minimally invasive
- standing sinus sx has a number of advantages (no anaesthetic risk, less haemorrhage, tolerated well)
— maxillary sinus flap
— front sinus flap
Exodontia - methods & indications
- commonly necessary for cheek teeth
- oral extraction if possible
- tooth repulsion via sinusotomy (care to get correct tooth, entire tooth and only the tooth)
- difficult to tx -> high risk of complications
Anatomy of the pharynx
Soft palate
- complete soft palate that separates the nasopharynx and oropharynx
– no common pharynx in front of the larynx like in other spp
– why obligate nasal breathers
- contact with sub epiglottic tissue during breathing
Guttural pouches
- ostia
- dz may compress pharynx
- nerve supply to pharynx may be affected
Conditions of the pharynx: DDSP - what is it?
Intermittent dorsal displacement of the soft palate
Conditions of the pharynx: DDSP - tx options, success rate
- staphylectomy (no longer recommended)
- myectomy (sternothyroid ± sternohyoid)
- palatal fibrosis (thermocautery or laser)
- tie forward (prosthesis to replace thyrohyoid muscle) (currently most popular and best success rate [80%])
- most have 60% success rate, determining success is difficult
- can have potential to make condition worse
Dynamic pharyngeal collapse - what is it? cause?
- collapse of pharyngeal wall when negative pressure highest
- ? dysfunction of mechanoreceptors and neuromuscular reflexes
- may be associated with GP tympana and DDSP
- tx options limited
Cleft palate - signs, diagnosis, prognosis & tx
- nasal reflex of milk / food material and aspiration pneumonia
- uncommon
- diagnosed on endoscopy
- poor prognosis -> recurrent infections and poor athletic function
- sx -> poor success rate, ? justified
Anatomy of the larynx
5 cartilages
- epiglottis
- cricoid
- thryoid
- paired arytenoids
Endoscopic view of the larynx
- rima glottidis
- soft tissue
– aryepiglottic folds
– vocal fold
– lateral ventricles
– laryngeal saccules