SA Approach to Regurgitation Flashcards
(15 cards)
Physiology of the esophageal phase of swallowing:
-Steps: Esophageal distention –> Sensory feedback –> Regulates contraction speed and intensity (Primary peristalsis = swallow induced; Secondary peristalsis = distention induced) –> LES relaxes with esophageal distention –> Bolus enters stomach –> LES closes then contracts to prevent reflux of contents
Upper Esophageal Sphincter:
-Composed of Cricopharyngeal muscle
-If it doesn’t open: Cricopharngeal achalasia or cricopharngeal asynchrony
-Clin signs of UES Issues: Dysphagia, dropping food, food sitting in back of throat
-Main clinical sign for problems with UES, esophagus, and LES == REGURGITATION
Characteristics of Regurgitation:
-The passive movement of material that has entered into the esophagus that then comes back out of the mouth
-Physical Exam: Palpate neck & thoracic inlet for masses, check for asymmetry, and pain; Auscult the trachea and chest for aspiration pneumonia, crackles, and coughs; On Neuro Exam look for mentation, gait, CNs, Muscle tone, proprioception, and spinal reflexes
Differentials for Regurgitation:
-Diseases of the esophagus:
-Esophagitis
-Esophageal stricture
-Esophageal FB
-Esophageal neoplasia
-Esophageal diverticulum
-Vascular Ring Anomaly
-Megaesophagus
-Diseases of the LES:
-Hiatal hernia
-Gastroesophageal reflux
Esophagitis:
-Inflammatory disorder of esophageal mucosa
-Most common cause of megaesophagus in dogs
-Main cause: Reflux under Gen. Anesthesia!!!!
-Other causes: Doxy and clindamycin in cats; Foreign bodies
-Clin. Signs: Wide spectrum but regurgitation is common
-Diagnosis: History & clinical signs; Normal labs; Normal thoracic rads; Definitive diagnosis requires endoscopy
-Treatment: Antacid meds, coating agents, prokinetics
Esophageal Stricture:
-Narrowing of the esophageal lumen
-Main Cause: Gastroesophageal reflux under Gen. Anesthesia!!!
-Other causes: Foreign body; Cats taking doxy or clindamycin
-Inflammation and exposure of the muscularis of the esophagus, fibroblasts proliferate and then contract –> stricture (due to scar tissue)
-Clin. Signs: Regurgitation, hard and/or painful swallowing; Salivation; Anorexia; Coughing; Weight loss
-Diagnosis: History and clinical signs; Contrast esophagram or fluoroscopic swallow study; Endoscopy
-Treatment: Balloon dilation of stricture; Treat esophagitis
-NEVER GIVE BARIUM TO A REGURGITATING ANIMAL!!!! Barium is thick and the body cannot absorb it; Iohexol is water based and can be more easily-absorbed so should be used
Esophageal foreign body:
-Dogs: Bones, raw hides, fish hooks, needles, sticks
-Cats: Toys most commonly
-Tend to get stuck at points where esophagus cannot distend (Thoracic inlet, heart base, diaphragmatic hiatus)
-Clin. Signs: Regurgitation; Hard and painful swallowing; Salivation; Anorexia; Coughing
-Diagnosis: History and clinical signs; Thoracic rads.
Esophageal Neoplasia:
-Tumor within or around esophagus
-Rare, less than 0.5% of all cancers in SA
-Dog: Fibrosarcoma and osteosarcoma are most common
-Cat: SCC most common
-Clin. Signs: Gradual onset of regurgitation; Progressive history; Dysphagia; Painful swallowing; Salivation; Weight loss
-Diagnosis: Thoracic rads. can be normal or may show esophageal dilation, intraluminal mass, or periesophageal lesion; Look for spirocerca egg on fecal float!!
Esophageal Diverticulum:
-Sacculation of the esophageal wall (Giant pouch)
-Causes: Congenital or acquired (FB, stricture, neoplasia, PRAA); Peri-esophageal inflammation and fibrosis; Plant Awns in Western U.S.A. !!!!
-Clin. Signs: Regurgitation; Difficulty swallowing; Retching
-Diagnosis: Thoracic rads. and can add contrast
Vascular Ring Anomaly:
-Vessel outside the esophagus that encircles it and causes compression from the outside
-Cause: Congenital abnormality of the vessels in the chest (95% are PRAA)
-Clinical Signs: Regurgitation once weaned from liquid food to solid food (puppies and kittens)!!!
-Diagnosis: Thoracic rads. +/- iohexol contrast
Megaesophagus:
-Focal or diffuse esophageal dilation and concurrent esophageal dysmotility
-Causes: Congenital (defect in vagus nerve); Acquired (Myasthenia gravis with or without thymoma, but most commonly severe esophagitis); Hiatal hernia, upper airway obstruction, polymyopathy/polyneuropathy
-Clin. signs: Regurgitation; Polymyositis; MG exercise intolerance; GI signs (Lead toxicity, hypoadrenocorticism)
-Diagnosis: Thoracic rads; Test for MG titer
-Treatment: Small frequent meals; Feed in upright position; Find consistency that works for the animal
Hiatal Hernia:
-Abdominal contents through or around the esophageal diaphragm opening
-Type 1: Sliding hiatal hernia (Stomach into esophagus); Congenital in shar-pei, chows, bulldogs, pugs, & boston terriers; Most commonly acquired = BOAS
-Clin. Signs: Intermittent regurgitation; Vomiting; Hypersalivation; Post-exercise; Signs of esophagitis; Respiratory signs
-Diagnosis: Survey thoracic rads; Push on abdomen with a spoon, look in caudal esophagus region; Esophagoscopy
Gastroesophageal reflux:
-Reflux of gastric or intestinal fluids or ingesta into esophagus
-Gastric acid pH 2-3; Pepsin; Trypsin; Bile salts reflux
-Prolonged contact of refluxed contents with esophagus mucosa leads to inflammation
-Inflammation –> esophagitis –> stricture
-Common causes: GA; Hiatal Hernia; BOAS; Chronic vomiting
-Clin. Signs: Regurgitation
Diagnosis: History; Thoracic rads; Response to treatment
Differentiating Regurg. V.S Vomiting:
-Regurgitation: No vomiting, salivation, or lip-smacking; No retching or abdominal contractions. There will be passive lowering of the head
-Vomiting: Nausea, salivation, and lip-smacking are common. Retching and abdominal contractions will be present as the animal actively tries to expel gastric contents.
-To truly distinguish you need to witness the act!!!
Meds. commonly used for causes of regurgitation:
-Proton pump inhibitors (Antacid meds.): Omeprazole, lansoprazole (Oral); Pantoprazole, esomeprazole (IV)
-Famotidine IV CRI (Antacid Medication)
-Barrier medications: Sucralfate
-Promotility agents (Tighten LES): Cisapride, Metoclopramide (Oral or IV)
-Relax the LES: Sildenafil (Oral)
-Anti-nausea Meds. (Only if vomiting!!): Cerenia, Ondansetron, and Metoclopramide
