Approach to Regurgitation Flashcards
describe the esophagus
- big tube that carries food and water from the mouth/throat to the stomach
- sphincter at top and bottom to keep things moving in the appropriate direction
- surrounded by muscle that contracts to propel a bolus forward
-very important for animals horizontal to the ground
what can go wrong with the esophagus?
- problem with sphincters
- something gets stuck in the tube
- something is in the way so things can’t move down the tube
- muscles dont or cant contract
- inside of the tube gets inflamed and causes pain
describe the esophageal phase of swallowing as relates to the UES
- swallow bolus, goes to back of throat, UES opens
- UES composed of cricopharyngeal muscle
-problem when it doesnt open
-disease: cricopharyngeal achalasia or asynhrony
–clinical signs: dysphagia, dropping food, food sitting in back of mouth
describe esophageal innervation
very complex! sympathetic, parasympathetic, and skeletal muscle (NMJ)! many points where it can go wrong!
describe the esophageal phase of swallowing as relates to the LES
- esophageal distension causes sensory feedback that regulates contraction speed and intensity (peristaltic waves)
-primary peristalsis: swallow induced
-secondary peristalsis: distension induced - LES relaxes with esophageal distension: bolus enters the stomach
- LES relaxes and then contracts to prevent reflux of contents
what is the main clinical sign for problems with the esophagus and LES?
regurgitation!
the passive movement of material that has entered into the esophagus that then comes back out the mouth
compare and contrast regurg to vomiting
regurgitation:
-no nausea, salivation, lip smacking/pro dromal signs,
-no retching or abdominal contractions, just passive lowering of the head
both above normal with vomiting
describe history questions to differentiate vomiting from regurg
- are they aware of an episode? change behavior before?
-nausea, drooling, moving to a different roome - is there an abdominal component or does it just come up?
- then clarify:
-appearance
-digested or undigested
-blood or black specks
-amount
-picture - when does it start?
-progressive, improvements, triggers, relations to eating and drinking, frequency - then clarify:
-meds, recent sx, recent anesthesia/sedation, historical surgeries, medical diseases - environment: indoor/outdoor, barn, couch
- routine:
-diet, amt frequency
-recent changes
-table food or treats
describe the physical exam for the regurgitating patient
- careful exam of the oropharynx:
-teeth, gums, palate
-tongue symmetry and motion
-watch them eat - palpate neck and thoracic inlet:
-masses
-asymmetry
-pain - auscult trachea and chest:
-aspiration pneumonia: BIGGEST CONCERN FOR REGURG PATIENTS BC CANNOT PROTECT THEIR AIRWAY
-crackles, coughing - complete neuro exam:
-mentation and gait
-cranial nerves (esp 9, 10, 11, 12)
-muscle tone/weakness
-proprioception
-spinal reflexes
give regurgitation differentials based on esophageal location
UES:
-cricopharyngeal achalasia or asynchrony
esophagus:
-esophagitis
-esophageal FB
-esophageal neoplasia
-esophageal diverticulum
-VRA
-megaesophagus
LES:
-hiatal hernia
-gastroesophageal reflux
describe esophagitis
- acute or chronic inflammatory disorder of the esophageal mucosa
-MOST COMMON cause of megaesophagus in dogs!! - causes:
-ingestion of caustic agents (abx: doxycycline and clindamycin in cats)
-chronic vomiting
-esophageal foreign bodies
-GE reflux during general anesthesia!!
–most common cause, inhalants and drugs and reflux all relax the LES
describe clinical signs and diagnosis of esophagitis
clinical signs: depends on severity
-mild: no to minimal
-mod-severe: anorexia, dysphagia, painful swallowing, REGURGITATION, hypersalivation
diagnosis:
-HISTORY AND CLINICAL SIGNS
-normal labs
-normal thoracic rads: unless megaesophagus
-definitive diagnosis requires endoscopy
describe esophageal stricture
- narrowing of the esophageal lumen
- causes:
-anything that causes esophagitis
–most commonly causes by gastroesophageal reflux under general anesthesia
–esophageal foreign body
-caustic swallowed substances
–CATS: doxycycline and clindamycin!! (liquid or pill)
-with inflammation and exposure of muscularis layer of the esophagus, fibroblasts proliferate and then contract leading to a stricture - scar tissue
describe clinical signs and diagnosis of esophageal stricture
clinical signs:
-REGURGITATION
-hard swallowing, painful swallow, salivation, anorexia, coughing, weight loss
diagnosis:
-history and clinical signs
-contrast esophagram or fluoroscopic swallow study (iohexol, not barium)
-endoscopy/esophagoscopy
why should you be careful with barium in any regurgitating animal?
barium is thick and the body cannot absorb it so if can’t pass or aspirate into lungs can lead to death!!!
iohexol is water-based and can be more easily absorbed
describe esophageal foreign bodies
- items in the esophagus that don’t belong in the esophagus
- causes:
-dogs: bones, raw hides, fishhooks, needles, sticks
-cats: toys most commonly
-tend to get stuck at points where the esophagus cannot distend: thoracic inlet, heart base, diaphragmatic hiatus
describe clinical signs and diagnosis of esophageal foreign bodies
clinical signs:
-regurgitation
-hard swallowing, painful swallowing!!!, salivation, anorexia, coughing
diagnosis:
-history and clinical signs
-thoracic radiographs: radiodense materal
–radiolucent material needs a contrast study (iohexol, not barium)
–look for aspiration pneumonia
–look for evidence of perforation: pneumothorax, pneumomediastinum
describe esophageal neoplasia
- tumor within or around the esophagus
- causes:
-rare! less than 0.5% of all cancers in the dog and cat
-dog: fibrosarcoma and osteosarcoma most common; often developing from granulomas (spirocerca lupi-only exists in warm temps)
-cats: squamous cell carcinoma most common
-peri-esophageal tumors from regional lymph nodes, thyroid, thymus, and heart base can have local invasion or direct extraluminal obstruction
describe clinical signs and diagnosis of esophageal neoplasia
clinical signs:
-gradual onset of regurgitation, progressive
-dysphagia, painful swallowing, salivation, weight loss
- +/- can palpate in cervical region
diagnosis:
-thoracic radiographs: can be normal or may show esophageal dilation, intraluminal mass, or peri-esophageal lesion
–eval lungs for metastatic disease and aspiration pneumonia
-look for spirocerca egg on fecal float
describe esophageal diverticulum
- sacculation of the esophageal wall (giant pouch)
- causes:
-congenital: secondary to embryonic development; most common
-acquired:
–obstruction inside (FB, stricture, neoplasia) or outside (PRAA)
–periesophageal inflammation and fibrosis; adhesion to adjacent tissue pulls the esophagys
-PLANT AWNS in the western US
describe clinical signs and diagnosis of esophageal diverticulum
clin signs:
-regurgitation
-difficulty swallowing, retching
diagnosis:
-thoracic rads
-add contrast (iohexol) to eval whether from esophagus or peri-esophageal structures
describe vascular ring anomaly
- vessel outside esophagus that encircles it and causes compression from the outside
-external esophageal stricture - causes:
-congenital abnorm of chest vessels
-85% are PRAA
-GS, irish setter, and breed
describe clin signs and diagnosis of vascular ring anomalies
clin signs:
-regurg ONCE WEANED from liquid to solid food
-puppies and kittens!
diagnosis:
-thoracic rads +/- iohexol
-CT with angiogram for definitive dx
describe megaesophagus
- focal or diffuse esophageal dilation and concurrent esophageal dysmotility
- causes:
-congenital: vagus nerve defect
-acquired:
–myasthenia gravis most common with or without thymoma
–MOST MOST COMMON: severe esophagitis
-hiatal hernia
-severe upper airway obstruction as a puppy or kitten (NP polyp or stenosis)
-polymyopathy/polyneuropathy
-hypoadrenocorticism
-lead or organophosphate poisoning
describe megaesophagus clinical signs and diagnosis
clinical signs:
-regurgitation
-muscle pain and stiff gait (polymyositis)
-generalized weakness (MG)
-exercise intolerance (MG, neuromuscular disease)
-GI signs (hypoadrenocorticism, lead toxicity)
diagnosis:
-thoracic radiographs
-test for MG: Ach receptor Ab titer (serum)
–if generalized weakness, can do an edrophonium test or see if the weakness gets worse with short exercise
-test for addison’s
-history about exposure to toxins
describe hiatal hernias
- abdominal contents through or around the esophageal diaphragm opening
- causes:
-type 1: sliding hiatal hernia 9stomach into esophagus)
–congenital in dogs: shar pei, chow chow, bulldogs, pugs, boston terriers
–MOST COMMONLY ACQUIRED: BOAS or abdominal trauma
-type 2: paraesophageal hiatal hernia (stomach alongside esophagus in caudal mediastinum)
-type 4: esophageal hiatal hernia: liver, stomach, and SI in thorax
describe clinical signs and diagnosis of hiatal hernias
clinical signs:
-INTERMITTENT REGURG
-vomiting, hypersalivation
-typically follows exercise or faster/deeper breathing
-signs of esophagitis
-respiratory signs: dyspnea, coughing
diagnosis: can be challenging if intermittent
-history and clinical signs
-survey thoracic rads (+/- contrast): push abdomen with a spoon, look in caudal esophagus region
-fluoroscopic swallow study (could be normal if intermittent)
-esophagoscopy
describe gastroesophageal reflux
- reflux of gastric or intestinal fluids or ingesta into esophagus
- gastric acis (pH 2-3), pepsin, trypsin, bile satls reflux and following prolonged contact with esophageal mucosa cause inflammation, esophagitis, and stricture
caused by:
1. general anesthesia
2. hiatal hernia
3. BOAS
4. chronic vomiting (weakens LES tone)
plus: stuff not moving out of stomach or nocturnal reflux: transient relaxation in LES during sleep with loss of swallow reflex
describe clinical signs and diagnosis of gastroesophageal reflux
clinical signs:
1. hard swallowing, hypersalivation, lip smacking
2. REGURGITATION: active, swallowed, or silent
diagnosis:
1. history: recent anesthesia, chronic vomiting
2. clinical signs: may be very subtle
3. PE: evidence of BOAS
4. thoracic radiographs!!
5. swallowing study: may see reflux
6. endoscopy: see evidence of esophagitis or wide open LES
7. response to treatment!!
