Swallowing Disorders Flashcards
Obj: Identify the phases of swallowing and correct order
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Obj: Given Signalment and CS, localize the site of dysphagia and formulate and prioritize a DDx list and Dx plan
Obj: Describe the clinical importance of differences in esophageal structure between species
Obj: Using imaging findings prioritize DDx for a patient with esophageal dysphagia
Obj: For specific diseases, formulate the most appropriate treatment plan and communicate complication and prognostic information to owners
What are the phases of swallowing
- Oral
- Pharyngeal
- Esophageal
Define Dysphagia
Difficult or painful swallowing
What is the diagnostic approach for dysphagia
- Complete history
- Physical and ORAL examination
- Observation of eating
- Neuro Exam
- Disease Localization
What happens during the oral phase of swallowing?
- Voluntary control
- Prehension of food
- Separation of bolus from bulk of food with tongue
- Pressure of tongue on hard palate ⇢ Caudodorsal movement of bolus
- Bolus in the pharynx initiates the swallowing reflex
What are the clinical signs of Oral Dysphagia?
- Ptyalism
- Chewing on one side
- Dropping food
- Excessive head movements during prehension
- Submerge muzzle to eat/drink
what is the diagnostic approach for Oral Dysphagia?
- Sedated Exam +/- Radiographs
- anatomic defects: Cleft palate
- Periodontal diseases/stomatitis
- Obstructive disease
What happens during the Pharyngeal phase of Swallowing?
- Reflex inhibition of breathing
- Pharynx narrows to move bolus caudally
- Relaxation of upper esophageal sphincter (UES)
- Constriction of pharynx ⇢ Bolus forced into caudal pharynx/through UES
What are the clinical signs of Pharyngeal/Cricopharyngeal Dysphagia?
- Repeated swallowing attempts
- Excessive neck movements during swallowing
- Gagging
- Coughing or immediate reflux of food/water
- Ptyalism
What is the diagnostic approach for Pharyngeal/Cricopharyngeal Dysphagia
- Radiographs (Oral/skull, cervical)
- Contrast Fluoroscopy
- Congenital cricopharyngeal achalasia
- Neuropathies: central or peripheral
- NMJ disorders: Myasthenia gravis
- Muscle disorders: muscular dystrophy, myositis
What is Cricopharyngeal Achalasia/Asynchrony?
- Congenital neuromuscular disorder in which the UES either:
- fails to relax (achalasia)
- Relaxation is discordant with pharyngeal contraction (asynchrony)
What is the common signalment of Cricopharyngeal Achalasia/Asynchrony?
- Young: weaning
- Breeds:
- Golden Retriever
- Cocker and Springer Spaniels
- Miniature Dachshunds
What are the clinical signs of Cricopharyngeal Achalasia/Asynchrony?
- Pharyngeal/Cricopharyngeal dysphagia
- Poor BCS, slow growth
- Aspiration pneumonia
How is Cricopharyngeal Achalasia/Asynchrony diagnosed?
- Contrast Radiography
- Fluoroscopy
- +/- serum creatine kinase, EMG, muscle biopsies
What is the treatment for Cricopharyngeal Achalasia/Asynchrony?
- Surgical myotomy of cricopharyngeal muscle
- Botulinum toxin injection
- Supportive care:
- Nutrition - Esophageal/gastric feeding tubes
- Pneumonia treatment
What happens during the Esophageal phase of Swallowing
- Constriction of UES (after bolus passes)
- Initial peristaltic wave moves from UES through entire esophageal length (Primary peristalsis)
- Incomplete food clearance ⇢ Esophageal distention ⇢ Secondary peristalsis
- Reflex relaxation of lower esophageal sphincter (LES)
Describe the structure of the Esophagus
- UES: Striated muscle
- Body:
- Dog – striated muscle
- Cat – Proximal ⅓ striated, distal ⅓ smooth muscle
- LES: smooth muscle
- Innervation: Vagus n. and branches
What is the diagnostic approach for Esophageal Dysphagia?
- Thorough history (Regurgitation*)
- Complete PE and Neuro eam
- Radiographs (cervical, thoracic)
- Generalized esophageal dilation: Megaesophagus
- Focal dilation: Stricture, diverticulum, vascular ring anomaly
- Radiopaque structure: foreign body
- Normal/non-diagnostic
- Fluoroscopy: performed in sternal recumbency
- Stricture
- Intraluminal mass
- Dysmotility or gastroesophageal reflux
- Normal → Esophagoscopy
- Fluoroscopy: performed in sternal recumbency
What is the difference between Megaesophagus and Esophageal Dysmotility?
- Megaesophagus:
- diffuse esophageal dilation and association of peristalsis
- Dysmotility:
- Decreased esophageal peristalsis or retrograde movement of food bolus w/out diffuse dilation
What are the Etiologies of Generalized Megaesophagus?
- Congenital:
- Idiopathic: Possible Vagal n. defect
- Congenital Myasthenia gravis (MG) or Hypothyroidism
- Acquired:
- Idiopathic
- Endocrine disease
- Neurologic disease
- Esophagitis
- Toxicity
- Thymoma (paraneoplastic)
What are the clinical signs of Generalized Megaesophagus?
- Regurgitation: time after eating varies
- Weight loss and poor BCS
- normal to increased appetite
- Aspiration pneumonia
- +/- systemic or neurologic disease
What is the diagnostic approach to Esophageal Dysmotility or Megaesophagus?
- Generalized: Thoracic Radiographs
- Dysmotility: Fluoroscopy
- Select cases:
- MG - Acetylcholine receptor antibodies
- T4 +/-TSH
- Baseline cortisol +/-ACTH stimulation test
- Muscle biopsy for congenital Myasthenia gravis
- Post-mortem - intercostal muscle
- Patients have generalized neurologic signs
- Esophagoscopy for evaluation of esophagitis
What is Regurgitation?
- Passive process
- Lack of lip-licking, retching, abdominal contractions
- “silent” action (lack of vocalization)
- Inability to predict timing
- if it contains food, poorly digested
- Usually does NOT contain bile
What is the treatment for Megaesophagus/Esophageal Dysmotility
- Treat predisposing disease if present
- Feeding adjustments
- Upright: Bailey chair
- remain upright 15-30 minutes after feeding → highly variable/adjust based on patient tolerance of food
- Adjust texture
- small meatballs, pate, ThickIT for liquid-intolerant patients
- Small, frequent meals
- Nutrient content
- Low-fat, easily digestible
- calorically-dense food may help reduce total volume needed to feed
- Percutaneous endoscopic gastrostomy (PEG)-tube placement
- does not decrease the risk of regurgitation/aspiration of saliva
- Upright: Bailey chair
- Medicaitons:
- treatment trial for esophagitis if recent history of vomiting or anesthesia
- Cisapride (Cats)
- Sildenafil (Dogs w/ congenital Megaesophagus)
Why is Cisapride not given to dogs for megaesophagus
- Prokinetic that increase LES tone may worsen clinical signs and are generally not recommended in dogs with idiopathic megaesophagus
What is the prognosis of generalized megaesophagus?
- MST 90days
- Worse with aspiration pneumonia and older age
- Variable but generally better for esophageal dysmotility w/out generalized megaesophagus
What are the common locations for Esophageal foreign bodies?
- Upper Esophageal sphincter
- Thoracic inlet (fishhooks)
- Heart base
- Immediately proximal to lower esophageal sphincter
What are the clinical signs of Esophageal foreign bodies?
- Acute onset dysphagia, gagging, regurgitation, hypersalivation
How is an esophageal foreign body diagnosed?
- Thorough oral examination
- Cervical/thoracic radiographs +/- contrast if radiolucent
- Do NOT use Barium, use Iohexal if concerned for perforation
- Esophagoscopy
When is surgery indicated for Esophageal Foreign Bodies?
- Esophageal perforation
- Extraluminal foreign body
What is the management for Esophageal Foreign Body following removal with moderate to severe esophagitis?
- Food/water restriction 12-24hr
- Low-fat, high protein diets
- Medications: Sucralfate, proton-pump inhibitors
- +/- PEG tube placement if severe esophageal damage
What are the possible complications of removal of a Esophageal Foreign Body?
- Esophagitis
- Aspiration pneumonia
- Uncommon:
- Esophageal perforation
- esophageal stricture
- Pneumothorax
- pneumomediastinum
- bronchoesophageal fistula
- cardiopulmonary arrest
- death
- longer time to removal increases risk of severe esophagitis and perforation
What is Esophagitis? Etiologies?
- Acute or Chronic Inflammation of esophageal mucosa
- Etiologies:
- Chemical Injury
- Ingestion of corrosive substances (doxycycline in cats)
- Gastroesophageal reflux
- secondary to general anesthesia or gastroesophageal reflux disease
- Less common: frequent, severe vomiting; Hiatal hernea and impaired acid protection
- Esophageal Foreign body
- Chemical Injury
What are the clinical signs of Esophagitis?
- Mildly affected patients may be asymptomatic
- Non-specific:
- Anorexia
- Esophageal dysphagia
- Painful swallowing
- ptyalism
How is Esophagitis diagnosed?
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Survey radiographs:
- normal, +/- esophageal dilation with severe disease, often focal and just proximal to LES
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Esophagoscopy:
- Mucosal erythema, erosions, alterations in mucosal texture
- Lesions most common in distal esophagus near the LES
- Lesions often appear striated de to gastric acid exposure pattern when esophagus is relaxed
- Esophageal Biopsies: rarely performed
What is the treatment for esophagitis?
- Nutritional management
- low-fat, high protein diet to facilitate gastric emptying and increase LES tone
- Small, frequent meals
- Medications:
- Sucralfate
- Proton-pump inhibitors
- Prokinetics to increase LES tone and facilitate gastric emptying
What is an Esophageal Stricture? Etiologies?
- Circular band of scar tissue within the esophageal wall, causing circumferential narrowing of the lumen
- Etiologies:
- Any cause of severe esophagitis
- Most common: Esophageal foreign bodies, secondary to gastroesophageal reflux
- 1-3 wks post-inciting event
- Any cause of severe esophagitis
What are the clinical signs associated with esophageal stricture?
- Regurgitation, multiple swallowing attempts
- May better tolerate liquids than solid food
- Ravenous appetite with weight loss
how are esophageal strictures diagnosed
- Contrast radiography or fluoroscopy
- Esophagoscopy
What is the treatment for Esophageal Strictures?
- Endoscopic or fluoroscopic-guided balloon dilation or bougienage
- repeated procedures often needed
- intra-luminal steroid injection may help decrease recurrence
- Supportive care for esophagitis
