Define Choke.
Esophageal obstruction
The cranial 2/3 of the esophagus are composed of ____ muscle, the caudal 1/3 is composed of ______.
The cranial 2/3 of the esophagus are composed of skeletal muscle, the caudal 1/3 is composed of smooth.
The ________ is the most common site for esophageal obstruction.
The thoracic inlet is the most common site for esophageal obstruction.
What is the most common etiological agent for primary esophageal obstruction?
• Most common: roughage, particularly leafy alfalfa hay
What are some predisposing diets?
Predisposing diets: hay cubes, large pellets, beet pulp
What are predisposing factors to primary esophageal obstruction?
Predisposing factors: poor mastication, gulping food, exhaustion, weakened/chronic debilitation
What are the 2 types of secondary esophageal obstruction?
- Intramural abnormalities → tumors (SCC), strictures, diverticula, cysts and vascular ring anomalies
- Extramural abnormalities → mediastinal or cervical masses → tumor abscesses
What kind of tumor is associated with secondary intramural abnormalities?
SCC
TRUE/FALSE
Ataxia is associated with choke.
FALSE
Staggering is but ataxia is a neurological problem.RULE IT OUT
What are the first signs of choke?
Ptyalism and dysphagia
Describe the relationship of the esophagus and the trachea through the neck of the horse.
- Cranial aspect located medial plan dorsal to trachea
- Midcervical region (C4-C5) esophagus shift to let left side of the trachea → when obstructions or tube can be visualized
- The thoracic esophagus lies ventral to the tracheal until it reaches the tracheal bifurcation where it resumes a dorsal position
TRUE/FALSE
An animal with choke will present with following signs?
- Gagging or retching
- Usually first signs are ptyalism & dysphagia
- Anxiety with neck extension
- Pawing
- Bilateral frothy nasal discharge (saliva/food material)
- coughing
- distention of the cervical esophagus may be evident
- Staggering: not ataxia (rule out)
- Colic
TRUE
______ can be associated with esophageal rupture if felt on palpation.
Crepitus can be associated with esophageal rupture if felt on palpation.
What landmark is used when measuing the NG tube?
13th ICS
______ should never be used when inserting a NG tube during a choke case.
Mineral oil or DSS should never be used when inserting a NG tube during a choke case.
What are the uses of ultrasound in a choke case?
- Cervical region very useful to confirm the obstruction
- Location and extent of the obstruction
- Evaluate aspiration pneumonia
What is the use of Radiographs during a choke case?
- Contrast study with air or barium
- Assess an esophageal impaction
- More useful after relief of the impaction → demonstrate strictures, diverticula, esophageal rupture or masses, esophageal dilatation
What is the treatment approach for choke?
- Relieve obstruction
- Reduce Esophageal tone & pain
- Physical Dispersion
- Post-obstruction monitoring
What are some drugs to reduce esophageal tone & pain?
- Acepromazine
- Xylazine & Butorphanol: combination had greatest effect on esophageal motility
- Detomedine
- Oxytocin: can reduce esophageal muscle tone suggesting it may be useful for relief of the obstruction
- Buscopan
Describe some methods to physically disperse the impacted material.
Nasogastric intubation
• Carefully lavage the esophagus
• External manipulation of the esophagus
• Head must be lowered to ground
• Dual tube method
• Supportive therapy → IV fluids (NaCl + KCl). Correct electrolyte imbalance & acid-base deficits.
• Maintain adequate oxygenation.
• With hold food for 24-48 hrs and reassess.
• General anesthesia (tilted table) → don’t want to anesthetize compromised horse already
• Surgery to massage the obstruction without cutting esophagus
• Time NPO w/ supportive care
TRUE/FALSE
Esophagostomy should be used once NG intubation fails
FALSE.
It is a LAST RESORT.
List the antimicrobials for each type of microbe:
- Gram +
- Gram -
- Anaerobe
- Gram + : K Penicillin
- Gram - : Gentamycin
- Anaerobe : Metronidazole
What gasatric drugs can be used post-obstruction?
Sucralfate / omeprazole
What is the purpose of performing an endoscopic exam immediately after relief of impaction?
to determine whether any complications are expected.
Also to investigate possible inciting cause of obstruction
