Week 2 - GI Flashcards
What does dyspahgia mean?
a SYMPTOM (not a diagnosis) - difficult/abnormal swallowing
What are the two classification of dysphagia?
- Oropharyngeal
-Oral
-Pharyngeal
-Cricopharyngeal (muscle related to upper esophageal sphincter/UES) - Esophageal - delayed
-exaggerated swallowing
Being a brachy sucks – why are they predisposed to dysphagia?
- stenotic nares
- elongated soft palate
- hypoplastic trachea
- inverted laryngeal sacules
How do brachycephalics get hiatal hernia?
bc they have a short muzzle > they have a mechanical obstruction in the upper airway (inspiratory stridor) > creates an increased negative intrathoracic pressure > this causes stomach to be sucked into chest cavity > weakness to diaphragm > hiatal hernia
When looking into dysphagia, which chem value should you look at?
CK!
and increased CK is not with Myasthenia Gravis
What is dysphonia?
-trouble talking/barking/meowing
caused by
neuropathy, junctionopathy, myopathy
How does anesthesia affect phagia?
-weakens LES tone (reflux can happen more easily)
-lose swallow reflex
What’s the difference between a video fluoroscopy and esophogram?
Esophogram
-giving contrast/barium by mouth – then taking radiograph right after
-2D dimensional image of esophagus
-document evidence of mechanical/anatomical defect in pharynx/esophagus
-single time point – can’t assess dynamics/motility
Video Fluoroscopy
-can assess dynamics/motility
-timing and opening of UES and LES
-can assess primary and secondary peristalsis
-assess reflux
-can assess everything from esophogram
What’s the Diagnostic Approach to the Dysphagic Dog?
- CT, MRI
- Electrodiagnostics (EMG, NCV) - helps with optimizing which muscle to biopsy
- Muscle biopsy
What are the muscles of mastication?
- pterygoid
- temporalis
- masseter
- digastric
What is MMM?
Masticatory Muscle Myositis
-autoimmune disease - dog’s immune system identifies the dog’s own muscle tissue as foreign and attacks it
-Inability to open the jaw under GA is a classical finding
-Usually bilateral
-Dobermans, Labradors, GSD, Rottweilers, Siberian husky, CKCS
What are some ways to DIAGNOSE MMM?
-CK may or may not be elevated! (acute yes, but could be normal if chronic)
-Serological assays: 2M antibody (ELISA)
–negative 2M doesn’t rule out MMM
-immunocytochemistry - false negatives if given corticosteroids within week
-Muscle biopsy - helps with diagnosis & long-term prognosis
What are the 2 types of Cricopharyngeal Muscle Dysphagia?
- Achalasia - Failure of cricopharyngeal muscle (CPm) to completely relax or open
-Idiopathic hypertrophy of the CPm
-there can also be LES Achalasia (achalasia is not sphincter specific) - Asynchrony - Inappropriate timing in opening of UES
-Idiopathic - thought to be a neuropathy
-UES does open, just at the wrong time
What are CS of Cricopharyngeal Muscle Dysphagia?
-Dysphagia within seconds of swallowing
-Repeated swallowing attempts
-Dysphagia usually worse with water
-Nasal reflux
-Coughing
-Bloating
What is the opening to the UES?
Cricopharyngeal bar
How do you TREAT Cricopharyngeal Muscle Dysphagia?
- open surgical myotomy - PREFERRED
-take out entire cricopharyngeal - Closed CO2 laser myotomy
-expensive, need special equipment - Botox injection of CP muscle - temp
-Botox causes temporary weakness of the CP muscle
-15 Units injected in 3 sites directly in the CP muscle
-Application of Botulinum Toxin - Balloon dilation of UES - temp
- Enteral feeding device - temp
What is Megaesophagus?
generalized loss of motor function to the esophagus results in dilation and loss of normal peristaltic motility. result - food and fluid accumulate in esophagus
Myasthenia Gravis is seen in ____% of all Megaesophagus cases
25%
Esophageal Achalasia occurs in about ___% of dogs with Megaesophagus
70%
Megaesophagus can be congenital/primary (idiopathic) OR acquired form: primary (idiopathic) or secondary to underlying disease
Congenital/Primary Idiopathic ME: puppies at weaning
Acquired/Primary Idiopathic or Secondary to underlying dz: myasthenia graves, SLE, polymyositis, polymyopathies, dermatomyositis, Addison’s. Esophageal obstructive diseases, if they’re chronic enough.
Acquired idiopathic of ME is most common in dog - German shepherd, Great Dane, Irish Setter
In terms of congenital megaesophagus…
-Never see focal megaesophagus alone with congenital myasthenia gravis
-will see focal MEGAESOPHAGUS + systemic weakness in a young puppy with MYASTHENIA GRAVIS
-will commonly see puppies with CONGENITAL MEGAESOPHAGUS without MYASTHENIA GRAVIS
There is 2 forms of Myasthenia Gravis
- Congenital - rare, NOT AUTOIMMUNE
-no need to draw blood for testing for antibodies bc not autoimmune - Acquired - autoimmune
-40% of cases only have focal ME without systemic weakness
-45% of cases have severe ME with systemic weakness
How can you DIAGNOSE Myasthenia Gravis?
- Acetylcholine Receptor Antibodies – if suspecting autoimmune MG
-normal is <0.6
-may be normal still if acute onset
How do you MANAGE Idiopathic Megaesophagus?
- Modify consistency of the diet and water
- Feed from elevated position
-Bailey Chair - Gastrostomy feeding tubes
How do you MEDICALLY MANAGE Esophageal Achalasia/Achalasia of LES?
Achalasia of LES > INCREASES LES tone
goal: drugs that will reduce tone of LES
Phosphodiesterases
-Sildenafil
-Botulinum toxin injection at LES
How do you SURGICALLY MANGE Esophageal Achalasia/Achalasia of LES?
goal: reduce tone of LES
- Heller myotomy of LES - open LES, decreases tone of LES
-con: may decrease tone too much and cause reflux - Fundoplication - to combat reflux, but can’t be too tight bc back at square one
DIS1-2, page 14
What does dysmotility mean?
foods and liquids do not easily pass down the esophagus
How was Coco’s Sliding hiatal herniation fixed? From DIS1-DIS2
3 surgeries
- gastropexy
- esophagopexy
- esophageal plication
What are the types of Hiatal Hernias?
- Type I Sliding Hiatal Hernia
-LES is above the diaphragm in chest cavity - Paraesophageal Hiatal Hernia
DIS1-2, page 16
What are the CAUSES of Esophagitis?
- Secondary to Anesthesia
-7.5 days post-anesthesia
-Presumed GER (incidence of gastroesophageal reflux under anesthesia is 16-55%) - Pill-induced esophagitis
-Doxycycline
-Clindamycin - Vomiting gastric contents
- Secondary to foreign body injury
- Secondary to ingestion of caustic material
When there is a decrease in tone/reduction in LES pressure, what can happen? This decrease is common under anesthesia.
GER - gastroesophageal reflux
-Morphine, atropine, acepromazine, thiopentol, xylazine, isoflurane
-Large-breed dogs (> 40kg; orthopedic surgery procedures)
How do you MANAGE esophagitis?
- Gastric acid suppressants
-Proton pump inhibitors (omeprazole, pantoprazole, etc.)
-H2-receptor antagonists (famotidine, ranitidine) - Sucralfate
3.Prokinetics
Cisapride
Metoclopramide
- Dietary fat restriction (more relevant in dogs than cats)
- PEG tube?
How does Sucralfate work in managing Esophagitis?
*Sulfated sucrose + polyaluminum hydroxide
– Binds to proteins electrostatically
– Stimulates PG production
– Adsorption of bile salts
– Inactivation of pepsins
- Adverse effects:
– Constipation
– Inhibit absorption of other drugs
works best in acidic environments, but usually given with PPIs – PPIs raise pH - make things more basic. So usually give sucralfate first, wait, and THEN PPI.
Sucralfate is a band-aid. Doesn’t truly fix issue.
How do PPIs and H2 blockers/antagonists work? Which is better?
PPI
-increase gastric pH, make more basic/less acidic. The H/K+ ATPase gets shut down, so not enough H to make acidic.
-better at suppressing acid
-not subject to tolerance
H2 blockers/antagonists
-block basal level of gastric acid secretion by binding to histamine type 2 receptors = decrease gastric acid production
-only works for a few days
when giving to these drugs – usually at least BID, then taper when need to discontinue (no cold turkey)
How does Cisapride work in managing Esophagitis?
-increases LES tone
-Stimulates gastric emptying
-Stimulates distal esophageal motility in cats, humans, guinea pigs
–Gastroesophageal reflux
–Esophagitis
CONTRAINDICATED in dogs with megaesophagus (dogs with ME already have increased tone of LES)
-also don’t give metaclopramide
Metaclopramide can be used for colonic motility. T/F
FALSE, cisapride helps with small intestine and colonic motility – NOT metaclopramide
What is vomiting?
-Forceful expulsion of gastrointestinal contents
-Active abdominal contractions
-Neurologically-mediated reflex
-retching and salivation
There are GI and Extra GI causes to vomiting. What are some examples?
GI
– Dietary indiscretion
– GI foreign body
– GI neoplasia
– Pancreatitis (Can also be extra GI)
– Infectious gastroenteropathy
– IBD
Extra GI
– Liver disease
– Renal disease
– Hyperthyroidism
– Toxin exposure
– Addison’s
– Heartworms
– Vestibular
What disease can cause chronic vomiting in cats?
Chronic small bowel disease is a common cause