Page 2267 - Cote clinical veterinary advisor dogs and cats 4th

Laryngeal, Pharyngeal, and Oral Examination 1125

Laryngeal, Pharyngeal, and Oral Examination
VetBooks.ir

○ Surgical instruments if palate or mass
Difficulty level: ♦
resection or biopsy anticipated and determine whether patient can extend
and retract tongue and open mouth fully.
Overview and Goal ○ Spay hook for palate retraction ○ Full oral examination occurs only after
The goal of nondental oral examination is to ○ Magnification glasses airway patency is verified, laryngeal func-
thoroughly evaluate the structure of the oral ○ Suction tion is assessed, and intubation performed.
cavity, nasopharynx, and larynx and to assess ○ Gauze sponges and Allis tissue forceps With practice, the veterinarian can observe
laryngeal function. Facial symmetry, cranial (sponge on a stick) for local tamponade multiple parts of the airway while these
nerve function, respiration, jaw movement, ○ Otoscope three steps are occurring, as described
and swallowing reflexes are evaluated in the below.
nonsedated animal. Thorough examination of Anticipated Time • Place an intravenous catheter, preferably
the oral cavity usually requires general anesthesia Approximately 15 minutes without opioid or acepromazine sedation. Procedures and Techniques
or heavy sedation. Infuse propofol to effect (usually up to
Preparation: Important 6 mg/kg IV). Have an assistant pass gauze
Indications Checkpoints tie caudal to maxillary canines to hold head
Diagnosis of neoplasia (pp. 711 and 714), • Expect general anesthesia for painful upwards.
inflammatory masses (p. 573), laryngeal examinations and intubation for surgery or • Under light anesthesia, open mouth with
collapse, laryngeal paralysis (p. 574), foreign if airway compromise is a concern. downward pressure on mandible. Note
bodies, fractures, elongated soft palate, oronasal • Multiple sizes of cuffed endotracheal tubes incisor/canine occlusion, ease of jaw retrac-
fistulas (including cleft palates [p. 180]), trauma in case airway is narrowed from obstruction tion, noise with temporomandibular joint
(p. 576), ranula, pharyngeal mucocele (p. 894), or collapse. May need a stylet (see below) (TMJ) movement, and presence of odor or
nasopharyngeal stenosis, epiglottic retroversion, • Preoxygenate before induction, and provide discharge.
and other oral conditions oxygen (intubation or flow-by) during the ○ When the mouth is closed, dogs and
exam. cats have a scissor bite: the crown of the
Contraindications • Extra propofol for intubation after laryngeal maxillary canine is lateral and caudal to
Should not be attempted with respiratory function exam is complete that of the mandibular canine; the tip of
distress until patient can be restrained safely • IV doxapram is given if no motion (normal the mandibular canine rests in a recess
for anesthetic induction and intubation or paradoxical) is noted during laryngeal rostrodorsal and lateral to the neck of the
function exam. maxillary canine.
Equipment, Anesthesia • Be prepared for placement of temporary ○ Acquired malocclusions can occur with
• Essentials tracheostomy tube (p. 1166). TMJ luxation, jaw/joint fractures, tooth
○ Anesthetic (e.g., propofol or inhalant), • Provide oxygen during recovery; nasal trauma, or neoplasia.
selection of endotracheal tubes catheters may be needed (p. 1146). ■ With unilateral rostrodorsal TMJ
For laryngeal exam, propofol 6 mg/kg luxation (most common), mandible is
■
IV to effect and doxapram 1 mg/kg IV Possible Complications and shifted and tilted ventrally to unaffected
Heavy sedation (e.g., dexmedetomidine Common Errors to Avoid side.
■
combined with an opiate) accept- • Laryngeal function exam: laryngeal paralysis ○ Resistance to opening mouth may occur
able if laryngeal function will not can be falsely diagnosed in animals under with pain, swelling, neoplasia, foreign
be evaluated too deep an anesthetic plane or that have bodies, fractures, TMJ luxations, retrobul-
○ SpO 2 monitor and pulse Doppler for not been given doxapram to stimulate deep bar or ocular disease, ear disease, tetanus,
patient monitoring inspiratory breaths. A diagnosis of laryngeal masticatory myositis, craniomandibular
○ IV access paralysis can be missed if laryngeal movement osteopathy, TMJ ankyloses.
○ Laryngoscope or flexible endoscope: high- is not correlated with normal respiratory ○ Inability to close mouth can occur with
quality, waterproof inspection cameras cycle (e.g., abduction on inhalation, adduc- TMJ malformation or luxation, foreign
(e.g., Depstech, www.depstech.com); tion on exhalation) if paradoxical motion body, soft-tissue swelling, neoplasia, tooth-
inexpensive and provide excellent visualiza- is present. to-tooth contact, trigeminal neuropathy.
tion and lighting of the oropharynx ○ Laryngeal function is decreased in normal • Grasp tongue with gauze sponge and pull
○ Gauze tie and sponge for jaw and tongue dogs when performed under acepromazine/ outward, or flatten base of tongue with
retraction, respectively propofol or ketamine/diazepam. laryngoscope to visualize caudal oral cavity.
○ Gloves • Dyspnea can occur during recovery because Concurrently evaluate tongue.
○ Dental speculum or assistant of swelling, hemorrhage, or positional com- ○ If tongue is difficult to pull from mouth,
○ Cotton-tipped applicators or tongue pression by normal soft tissues, particularly look for ankyloglossia (short lingual
depressor for soft-tissue retraction in heavily sedated animals. Anxiety on frenulum), lingual or sublingual neoplasia,
• May also need recovering can cause panting, which increases lingual trauma, lingual abscess, foreign
○ Stylet (e.g., polypropylene urinary cath- negative pressure on the airway, increasing body.
eter) for endotracheal tube if intubation the risk of swelling and obstruction. ○ Dorsal surface of tongue is covered with
will be difficult papillae.
○ Dental mirror if flexible endoscope not Procedure ○ Lingual lesions: neoplasia, ulcers, trauma,
available • Before anesthesia, evaluate facial symmetry, foreign bodies, eosinophilic granuloma
○ Focused light source (e.g., headlamp) skull anatomy, skin, lymph nodes, salivary complex, calcinosis circumscripta, contact
○ Needles and syringes, slides, cotton-tipped glands, globe retropulsion, respiration, burns from caustic ingestion, calicivirus
swabs, Tru-Cut biopsy needles, and for- nasal airflow, capillary refill time, mucous stomatitis, uremic glossitis, electrical cord
malin jars for cytology and histopathology membrane color, cranial nerve function, burns, swelling from circumferential string
samples jaw movement, and swallowing reflexes, or hair foreign body

www.ExpertConsult.com