GI pt. 1 Flashcards
GI pt. 1
3 Classifications of dysphagia
- Oropharyngeal
- Esophageal
- Gastroesophageal
3 subtypes of oropharyngeal dysphagia
- Oral – difficulty prehending and transporting food or water to the oropharynx
- Pharyngeal – Pharyngeal weakness secondary to a polyneuropathy or polymyopathy, or pharyngeal foreign body or neoplasia
- Cricopharyngeal – Failure of the bolus to pass through the cricopharyngeus region
Oropharyngeal dysphagia
- exaggerated swallowing movements and food will usually drop from the mouth within seconds of swallowing
Esophageal Dysphagia
more delayed regurgitation and is usually not associated with exaggerated swallowing movements.
Gastroesophageal Dysphagia
typically associated with a sliding hiatal hernia or abnormal decreased tone in the lower esophageal sphincter causing gastroesophageal reflux
Odynophagia
painful swallowing, often associated with esophageal foreign body or esophagitis
T/F: the cricopharygeal muscle is a vital part of the upper esophageal sphincter
T
Retching
an involuntary and ineffectual attempt at vomiting
Gagging
reflexive contraction of the constrictor muscles of the pharynx resulting from stimulation of the pharyngeal mucosa.
Diagnosis of swallowing disorders (History)
Age of onset is important Liquids vs solids Intermittent vs progressive Temporal pattern w/ swallowing Recent gen. anesthesia Dysphonia? Odynophagia Medications
T/F: an ability to ingest liquids fine, but inability to ingest solids is indicative of some form of structural abnormality, esophagitis, or vascular ring anomaly.
T
What is one of the most valuable tools when checking a dysphagic patient?
actually watching the animal attempt to eat/ drink
Diagnostic Approach to the Dysphagic Dog
- physical and neuro exam
- observe the animal eating and drinking
- CBC, Chem (including CK)
- survey rads
- Esophagram vs Videofluroscopy
- Esophagoscopy
- EMG and NCV
T/F: Dysphagia is not a diagnosis, it is a clinical sign.
T
Masticatory Muscle Myositis
- often present with an inability to open the jaw (trismus), jaw pain, and swelling/ atrophy of the masticatory muscles
- Diagnostics should include CK, 2M antibody test, and muscle biopsy
- Treatment with aggressive immunomodulatory drugs - cyclosporine, pred
T/F: muscles often affected by MMM are: masseter, temporalis, pteygoid, frontalis, and digastric.
F: the frontalis is not affected and so a muscle biopsy taken is not indicative/ useful for establishing MMM
Cricopharyngeal Muscle (CPm) Dysphagia
- Classified as either an Achalasia or Asynchrony, but have similar clinical presentations
- Clinical Signs: dysphagia immediately upon swallowing, repeated swallowing attempts, dysphagia worse w/ water, nasal reflux, bloating, coughing
- Diagnostics: Video-fluroscopy, rule out other causes
- Treatments: Surgery (myotomy - ideal), Botox injection (temp. repair for couple months), Balloon dilation of UES (not great alone)
- Prognosis - extremely variable
What are the two causes of nasal reflux
- Cleft pallate
- CPm achalasia (normally, but can also be asynchrony)
CPm Achalasia vs Asynchrony
Achalasia:
- failure of UES to relax
Asynchrony:
- failure of UES relaxation to time with pharyngeal contraction
Megaesophagus (Congenital Form)
- usually manifests in puppies at the time of weaning
- most likely due to a delay in maturation of the esophageal neuromuscular system
Megaesophagus (Acquired Form)
- Primary (idiopathic)(roughly 52%) or Secondary (to a large number of systemic disorders such as MG (roughly 25%), Addison’s, SLE, polymyositis, etc)
- Acquired idiopathic form is the most common in the dog (GSD, Great Dane, Irish Setter)
T/F: the biggest concern for an animal presenting with megaesophagus is the risk of aspiration pneumonia.
T
Megaesophagus (clinical Signs)
- regurgitation
- anorexia
- drooling,
- pain on swallowing (secondary to esophagitis)
Megaesophagus (Diagnostics)
- radiography ( Also, enlargement of the cranial eso with normal distal eso indicates a vascular ring anomaly or stricture)
T/F: We are concerned that a dog’s presentation of megaesophagus is secondary due to MG. However, the serum AChR-Abx come back only at high normal. What do we make of this?
- we are still concerned for MG so we will re-run the titers in a couple months to see if we simply caught the disease early on
Management of Megaesophagus
- modify feeding practices (animal should be fed in a vertical position and kept there for 5-10 minutes after eating)
- if esophageal achalasia exists, you can treat that with botulism injections too
- gastrostomy tubes are entirely viable options as well
Megaesophagus (Prognosis)
- idiopathic is poor due to the risk of aspiration pneumonia
Esophageal obstruction
- can be intraluminal (foreign body), intramural (stricture), or periesophageal (inflammation, neoplasia, hilar lymphadenopathy, vascular ring anomaly [persistent right aortic arch])
Esophageal foreign body
- can result in severe ulcerative esophagitis, esophageal perforation, or stricture formation
- diagnose via radiograph
- treatment via removal of foreign body
Intramural esophageal obstruction
- often a result of stricture formation
- treatment via
- -> balloon catheter dilators (multiple treatments),
- -> Sucralfate (good for stricture ass. esophagitis),
- -> give an H2 or PPI to decrease esophageal mucosa damage
Peri-esophageal
- obstruction via inflammation, neoplasia, hilar lymphadenopathy, and vascular ring anomalies (persistent right aortic arch)
Esophagitis
- inflammation of the esophagus resulting from ingestion of caustic agents, chronic vomiting, foreign body obstruction, reflux esophagitis
- results from a loss of competency of the gastroesophageal sphincter and subsequent reflux
- can results from general anesthesia (important), pill-induced (doxy, clinamycin, NSAIDs)
Esophagitis (Treatment)
- removing underlying causes
- Sucralfate
- PPIs and H2 blockers
- Prokinetics (Cisapride and Metaclopramide)
- Dietary Fat Restriction
H2-antagonists vs PPI
- PPIs are significantly more potent than H2’s
- H2’s suffer from tachyphylaxis (buildup of tolerance to certain drugs)
Myasthenia Gravis
- 40% megaesophagus only
- 45% megaesophagus + gen. weakness
T/F: the incidence of gastroesophageal reflux varies between 16-55% depending on the measuring device, type of surgery and larger size
T
T/F: Cisapride is contraindicated in patients with megaesophagus
T
Ondansetron
potent selective 5HT3 receptor antagonist
- CRTZ, Vomiting Center, and GIT/Pharynx, (no vestibular nuclei)
Cerenia/ Maropitant
Substance P inhibitor
- CRTZ, Vomiting Center, and GIT/Pharynx (no vestibular nuclei)
T/F: the vestibular nuclei connect directly to the vomiting center in the dog while they must pass through the CRTZ in the cat.
False, signals must pass through the CRTZ in the dog while they can pass directly to the vomiting center in the cat
Name some breeds predisposed to MMM
- labradors
- Dobermans
- GSD
Breed Disposition to Cricopharyngeal Achalasia?
- mini dashchunds, toy breeds
Breed Disposition to Cricopharyngeal Asynchrony?
- Golden Retrievers
Cisapride
- increased LES tone
- stimulates gastric emptying
- stimulates distal esophageal motility (cats)
useful in GERD and esophagitis
contra in dogs with megaesophagus
Which two anesthetic drugs do not decrease LES tone?
- ketamine
- propofol
Which two anesthetic drugs do not decrease GI motility
- alfaxalone
- benzodiazepines
Approach to vomiting patient
- keep head down to prevent aspiration
- induce quickly (no opioids or inhalants)
Approach to regurgitating patient
- keep head up to prevent regurge
- induce quickly
- have suction ready
Anesthetizing patients with GERD (risk factors)
- increasing age
- surgery type
- longer fasting time
- drugs used
Anesthetizing patients with GERD (non-risk factors)
- position of the patient
- type of inhalant used
Top complications of anesthetizing GI patients
- Esophagitis
- Aspiration pneumonia
GI Vomiting Causes
GI:
- Dietary Indiscretion
- GI foreign body
- GI neoplasia
- infectious gastro-enteropathy
- IBD (inflammatory bowel disease)
Extra-GI Vomiting Causes
Extra-GI:
- Hyperthyroidism
- Hepatic Dysfunction
- Renal Failure (uremic acids)
- Addison’s
- pancreatitis
Top causes of chronic small bowel disease –> vomiting in the cat?
- IBD (49%)
- Lymphoma (46%)
- Mast Cell Disease (3%)
- Adenocarcnimoa (1%)
Two pathways for the vomiting reflex
- CRTZ (bloodborne) - humoral pathway
- renal failure, liver disease, digoxin toxicity, endotoxemia, apomorphine - Vomiting Center (neural reflex) -
- GI infection, inflammation, toxicity, malignancy
4 components of the vomiting reflex
- visceral receptors in the gi tract
- sympathetic and vagal affarent neurons (synapse in vomiting center)
- CRTZ
- Vomiting Center
Regurgitation vs Vomiting
Regurge: - no prodromal nausea - passive - seconds-hrs Vomiting: - active, abd contractions - prodromal nausea - minutes-hours
T/F: cats to do not have very good dopiminergic receptors which makes apomorphine (agonist of D2) and metoclopramide (D2 antagonist) not very effective
True, these work very well in the dog, but are almost completely useless in the cat
Management of the acutely vomiting dog/ cat
- crystalloid fluids
- antiemetics
- dietary management
- broad spectrum angelmenthics
Don’t - NPO, gastric acid suppressants, antibiotics, corticosteroids
What is the value of the chemistry profile in the vomiting patient?
- rule out metabolic diseases/ extra-gi causes such as renal, hepatic, addison’s, diabetes, hypercalcemia, etc.
Chronic gastritis
- can have many different problems including IBD, foreign body, toxin ingestion, infections, etc.
Esophageal acalasia (treatment)
- sildenafil
- botulism injections
Shortcomings of PPI vs H2
- H2 suffers from drug tolerance
- PPIs are significantly more potent
Helicobacter spp.
- present in ~50% of healthy dogs and cats
- causes a lymphofolicular gastritis
- treat with triple therapy ( clarithromycin, metranidazole, PPI)
Metoclopramide
- D2 antagonist (anti-emetic), minor 5HT3 (anti-emetic) and 5HT4 (prokinetic)
- antiemetic (not in cats)
- prokinectic drug (less effective than cisapride and does not touch the oclon)
- best given as CRI
Ondansetron
- 5HT3 antagonist
- can be given IV, SQ, orally
- v potent antiemetic in dogs and cats
alpha-2 Adrenergic Antagonist
- Chlorpromazine, Prochorperazine, Yohimbine
- anti-emetics, increase GI motility
Diphenhydramine
- H1 histaminergic blocker
- useless in cats d/t lack of histaminergic receptors
Cerenia (maropitant)
- NK1 receptor antagonist, prevents Substance P binding
- highly effective antiemetic in cats and dogs
- can help reduce visceral pain
GI protectant - Sucralfate
- electrostatic binding to the mucosal proteins exposed during ulceration
H2-blocker
- Fomotidine, Ranitidine (never give Cimetidine)
PPI
- more potent than H2’s, must give 30-45min before meal
- Omeprazole, Esomeprozole
Misoprostal
- PGE1 analogue
- not commonly used in vet med
- increased mucosal blood flow, epithelial cell turnover, mucus secretion, decreased gastric acid secretion
- no advantage over H2 blockers for treating ulcers
How to assess intestinal viability?
- color
- consistency
- motility
- bleeding/ perfusion
What is the primary holding layer in the GI
- submucosa
Gastric Closure
- 2 layer closure:
- -> mucosa/submucosa
- -> muscularis/ serosa (inverted pattern)
Small/ Large intestine closure
- single layer appositional, must include submucosa
- inverting will decrease lumen size
Methods for dealing with lumen disparity
- Place suture at wider interval on larger side
- Transect the side with the smaller diameter obliquely
- Spatulate Smaller sides
- Suture anastomosis and close mesenteric rent
Adverse factors affecting wound healing in the Large Intestine
- dehisce at a higher rate than the small intestine
- wound strength returns more slowly than small intestine
- poorer blood supply in mid-rectum
- large anaerobic load present
- Tension: reduces blood supply, oxygen tension
Indications for colo-rectal resection
- colonic neoplasia
- feline megacolin
- rectal neoplasia
- colonic foreign bodies - can usually be removed without surgery
Diagnostic approach to rectal masses
For lesions close to anocutaneous jxn: - FNA, core biopsy, incisional biopsy - might require mucosal eversion For more proximal lesions: - proctoscopy or colonoscopy Lymph node aspiration Colotomy for colorectal jxn tumors not recommended
Common indications for anal sac surgery
- Anal sac adenocarcinoma
- anal sacculitis/ infection/ impaction
Common complications for anal sac surgery
- infection
- fecal incontinence
- recurrence of disease (particularly neoplasia)
Small vs Large Bowel Diarrhea
- frq
- V
- blood
- mucous
- tenesmus
- urgency
- vomiting
- weight loss
Small: n frequency, n volume, melena, no mucous, no tenesmus, no urgency, yes vomiting, yes weight loss
Large: incr frequency, dec volume, hematochezia, yes mucous, yes tenesmus, yes urgency, vomiting less common, no weight loss
CIBDAI (IBD activity index)
- reserved for chronic gi disease
- -> attitude/ activity
- -> appetite
- -> vomiting
- -> stool consistency
- -> stool frq
- -> weight loss
Most common causes of Acute Diarrhea
- dietary indiscretion
- foreign body
- infectious
- antibiotics
- chemotherapy
Most common causes of Chronic Diarrhea
- food responsive enteropathy (#1 most common)
- antibiotic-responsive enteropathy (dogs)
- steroid-responsive enteropathy (IBD)
- infectious
- neoplasia
T/F: a majority of acute diarrhea cases are self resolving and require no significant treatment other than possible supportive
T
T/F: Diagnosis of Food-RE and Antibiotic-RE are only based off of signalment and history while Steroid-RE requires biopsy
T
T/F: Gravitational centrifugation is 7x more sensitive than gravity flotation for when detecting protozoa such as Giardia
T
Diagnostic approach to diarrhea in dogs and cats (3 questions)
- Acute or Chronic
- GI or extra-GI
- Small or Large bowel
Giardia
- most common sign is asymptomatic animal
- associated w/ small bowel disease
- most strains are non-zoonotic
- often self-limiting
Giardia (Direct wet-prep)
- looking for motile trophozoites; falling leaf motion
- high change for false neg
- feces must be <1 hr old
- drop of saline + small volume of fresh diarrhegic feces
Giardia (Firect Fluoresent Immunoassay)
- this is a dual assay and will highlight both giardia and cryptosporidium (crypto is significantly smaller)
Giardia (treatment)
- metronidazole (only 67% effective)
- fenbendazole (>80% effective)
- Ronidazole (macrolide can cause neurotox in cats)
- Drontal plus (3 dif. drugs)
- Secnidazole
T/F: Treatment of T. foetus in cats is best controlled with either metronidazole or fenbendazole
F; treatment is best with Ronidazole however there is slight concern for neurotoxicity
Abx for C. perfringens
- Ampicillin, Metro, Tylosin
Abx for Campylobacter
- Erthyromycin, enrofloxacin
Abx for C. Difficile
- Metronidazole
Treatment of Abx-RE
- Tylan is superior
- Metronidazole can cause nausea, vomiting, neurotox
T/F: Giardia detection via ELISA can only be used for initial diagnosis and not any further follow-ups to see if the infection has cleared
T; Giardia cysts can be present in the feces for months post-resolution and so ELISA is not an accurate measurement technique
What are some major differences between T. foetus and Giardia?
- T. foetus is mainly cats while Giardia is mainly dogs
- T. foetus is large bowel diarrhea while Giardia is small bowel
- T. foetus has no cyst stage so fecal flotation not possible
Indications for fecal culture/ PCR
- acute onset hematamesis or bloody diarrhea w/ systemic signs of sepsis
- zoonotic ramificiations
- hemorrhagic diarrhea in an immunocompromised patient
Food Responsive Enteropathy
- ;most common form of chronic enteropathy
- younger dogs and cats
- large bowel signs predominate
- disease activity index is low
Food-RE (Dietary Management)
- limited ingredient
- hydrolyzed
- fat-restricted (<20% by per calorie)
- highly digestible
- fiber modification
T/F: Dietary therapy for Food-RE is both diagnostic and therapeutic
T
Food-RE (Prognosis)
- younger dogs w/ less severe disease and predominance of large intestinal signs are more likely to respond rapidly to elimination diets alone
Food-RE (Neg Prognostic factors)
- high clinical activity index
- low B12
- low albumin
Food-RE (Indications for feeding hypoallergenic Diet)
- complicated diet history
- diagnosis and management of Cutaneous Adverse Food reaction
- allergic to multiple allergens
Antibiotic -RE
- not the same as SIBO
- a dysbiosis exists but not necessarily an overgrowth
- young, middle aged large and giant breed (GSD)
- mild lymphocytic-plasmacytic duodenitis w/ no architecture changes
Antibiotic-RE (Treatment)
- Tylan (macrolide)(unknown moa)
Steroid-RE (pathogenesis)
- overly aggressive T-cell response to a subset of commensal enteric bacteria develops in a genetically susceptible host
- -> luminal antigens
- -> genetic suscuptibility
- -> env. triggers
IBD - Clinical Criteria
- persistence of gi signs >3 weeks duration
- failure to respond to symptomatic signs treatment
- failure to document other causes of gastroenteritis
- hist diagnosis of benign intestinal inflammation w/ villus blunting/ fusion or changes in crypt
Steroid-RE (Diagnostic Approach)
- requires biopsy for diagnosis
- elimination diet trial +tylosin trial
- measure B12 + Folate
- US –> thickening of muscularis layer
- endoscopy –> biopsy
2 Limitations of endoscopic biopsy for IBD
- length of endoscopy tube
2. depth of the sample
Management of IBD (2 types)
- lymphocyte-plasma cell IBD –> treat with diet, abx, immune suppress
- Granulomatous or neutrophilic IBD –> ass. with infection, do not immunosuppress
B12 Deficiency causes
- dec ileal absorption
- dysbiosis
- dec. intake
- dec. gastric acidity
Management of non-specific colitis
- Fenbendazole
- Elimination Diet
- Tylosin
- +/- Pred
Granulomatous Colitis
- plasma cells, lymphocytes, PAS-positive macrophages
- Treatment: fluoroquinolones for 6-8wks
- Cause: Boxer macrophages lack a certain enzyme capable of breaking down E. coli from the intestine
PLE (Major Causes)
GI Inflammation --> IBD --> Histoplasmosis --> intestinal pythiosis Gi Ulceration --> intestinal lymphoma --> ulcerative enteritis/ gastritis --> intussusception Primary Intestinal Lymphangiectasia
Primary Intestinal Lymphangiectasia
- small bowel diarrhea
- panhypoprotenemia and lymphopenia
- hypocholesterolemia and hypocalcemia
- malabsorption of fat and fat soluble vitamins
Explain the relationship between decreased Calcium and Magnesium
…ask butt for help…
Primary Intestinal Lymphangiectasia (management)
- fat restricted diet (<20%)
- elimination diets for concurrent IBD
Indications for Abx therapy w/ GI disease
- hemorrhagic diarrhea w/ signs of sepsis
- prevent bacterial translocation
- severely immunocompromised patient
- management of abx-responsive diarrhea (ARD)
- Management of a specific bacterial enteropathogen
EPI (Clinical Signs)
- Polyphagia
- Weight Loss
- Small Bowel Diarrhea
- Poor body condition
What is the diagnostic test of choice for EPI
TLI - Trypsin-like Immunoreactivity
–> picks up both trypsin and trypsinogen
EPI (Treatment)
- Pancreatic enzyme supplementation
- Diet: highly digestible diet (avoid high fiber)
- Vit. B12 supplementation
- abx: only if refractory or abx-re develops
- fat soluble vitamins
- acid suppressants (not used)
EPI (prognosis)
- good w/ proper treatment
- better prognosis w/ B12 supplementation
EPI (reasons for poor response)
- lack of owner compliance
- plant based enzymes
- B12 not given
- not on high digestible diet
- dysbiosis not addressed
- occult concurrent GI disease
T/F: EPI =
Dogs = Polyphagia + weight loss + small bowel diarrhea
Cats = mainly weight loss
T
4 functions of Sucralfate
- binds to proteins electrostatically
- stimulates PG production
- adsorption of bile salts
- inactivation of pepsins
Common Names?
- Metoclopramide
- Ondansetron
- Maropitant Citrate
- Sucralfate
- Omeprazole
- Reglan
- Zofran
- Cerenia
- Carafate
- Prilosec
What are 4 causes of a discordant BUN:Cr
- emaciation/ starvation
- gi hemorrhage
- dehydration
- high protein diet
