Gastroenterology Pt. 3 Flashcards
causes of acute regurgitation (6)
-FB (esophagus)
-Acute esophagitis (caustics, previous vomiting, previous FB)
-Esophageal dysmotility, megaesophagus
-Esophageal stricture (more chronic)
-Hiatal hernia (more chronic)
-Addison’s disease
common types of esophogeal foreign bodies
¡ Bone is most common
*Also: Gristle, rawhide, fish hooks
signs of esophageal foreign body
¡ Hypersalivation, odynophagia (painful swallowing), repetitive swallowing, halitosis
breed overrepresented for esophogeal foreign bodies
¡ Westies over-represented
Locations where we may see an esophogeal foregin body on a radiograph
¡ Immediately caudal to larynx
¡ Cervical esophagus
¡ Thoracic inlet
¡ Base of heart
¡ Cranial to diaphragm
> Radiograph not as dramatic as may expect
acute complications of an esophageal foreign body
¡ Aspiration pneumonia
* Cough, tachy/dyspnea, nasal discharge, fever
¡ Esophageal perforation
* Tachy/dyspnea, fever
¡ Airway obstruction
* Trachea compressed at base of heart
* Especially puppies
* Choking, dyspnea, cyanosis, CP arrest, cannot expand lungs after intubation
esophageal foreign body treatment
¡ Emergency
¡ Refer for endoscopic retrieval or surgery
¡ Sucralfate liquid, pink lady (viscous lidocaine & aluminum hydroxide), famotidine/omeprazole, analgesia
¡ Feed as usual?
¡ Surgery
> If endoscopy unsuccessful
> Caudal esophageal FB may often be removed by gastrotomy
> Thoracotomy
* Likely needed if esophageal perforation
ESOPHAGEAL FOREIGN BODY: PROGNOSIS
¡ Prognosis good in most cases
> Chronic complication:
* Esophageal stricture (cicatrix) = 10% risk
* More likely if perforation or surgery >Continue to regurgitate
>Confirmed with esophagram, endoscopy
gastric mucosal barrier consists of what? what happens if there is a disturbance to any of these?
¡ Gastric mucosal barrier consists of:
> Bicarbonate-rich mucus
> Mucosal cells
> Blood supply
¡ Disturbance to any of these:
> Damage by gastric acid and pepsin
> Risk for ulceration
what are the protective mechanisms and aggressive factors that prevent or contribute to GI ulceration
Imbalance between:
¡ Protective mechanisms:
- Decreased mucous secretion
- Decreased bicarb secretion
- Decreased prostaglandins
- Decreased mucosal blood flow
¡ Aggressive factors:
- Direct injury
- Increased gastric acid secretion
3 broad classifications of GI bleeding
- overt
- Occult
- Obscure
what is overt GI bleeding?
- Grossly visible
- Hematemesis, hematochezia, melena
what is occult GI bleeding?
- Hemorrhage that is not visible
- Manifested as positive fecal occult
blood test or iron deficiency anemia
what is obscure GI bleeding
- Recurrent GI bleeding in which a source cannot be identified
localization of GI bleeding: two categories
¡ Upper GI bleeding: bleeding oral to duodenojejunal junction
¡ Lower GI bleeding: bleeding aboral to ligament of Treitz
hematemesis: what are the signs, what is the source and localization? differential diagnosis?
Vomiting of blood:
¡ Frank blood (fresh)
¡ Coffee ground vomiting
- Black pigment: hematin = oxidized heme
¡ Source of blood: GI bleeding or swallowed blood
¡ Localization of GI bleeding: Upper
¡ Differential diagnosis: hemoptysis
melena: what are the signs, what is the source and localization? differential diagnosis?
¡ Black, tarry stools
¡ Required amount of blood:
> Dogs: 350-500mg hemoglobin/kg
¡ Source: GI bleeding or swallowed blood
¡ Localization: upper GI > lower GI
> Lower GI and delayed transit time
¡ Differential diagnoses: medications (ferrous sulfate, activated charcoal, bismuth suspensions), raw food, blueberries
hematochezia: what are the signs, what is the source and localization? differential diagnosis?
¡ Bright red-coloured stools
¡ Source of blood: GI bleeding
¡ Localization: lower GI > upper GI
> Upper GI and increased transit time
¡ Differential diagnoses: food containing red food colouring, large amounts of beets, perineal wound, anal sac abscess
causes of GI ulceration
¡ Drugs
* NSAIDS – most important in dogs
> NEVER give meloxicam/other NSAIDS to a vomiting dog
* Corticosteroids – important co-factor
¡ Primary GI
* Neoplasia – adenocarcinoma, lymphoma
* Foreign body
* Inflammatory bowel disease (uncommon)
* Fungal infection (rare)
¡ Secondary GI:
* Pancreatitis
* Liver failure
* Kidney failure
* Hypoadrenocorticism (Addisons)
* Mast cell tumour
* Systemic disease (GI ischemia + stress)
* Pancreatic gastrinoma (rare)
use of radiographs and ultrasound for GI bleeding
¡ Radiographs unremarkable
> Most useful to identify foreign body
Ultrasound:
¡ Can identify some ulcerations
¡ Local thickening of gastric wall
¡ Loss of layering, wall defect
¡ Fluid accumulation in stomach
¡ Reduced gastric motility
diagnostics for stomach bleeding
¡ Exploratory Surgery
¡ Flexible Endoscopy
¡ Capsule endoscopy (ALICAM, PillCam)
diagnostics for duodenal bleeding
¡ Exploratory Surgery
¡ Flexible Endoscopy
¡ Capsule Endoscopy
diagnostics for jejunal bleeding
¡ Exploratory Surgery
¡ Capsule Endoscopy
capsule endoscopy vs flexible endoscopy vs surgery - differences in diagnostic methods for GI bleeding
Capsule:
-visualization
-no biopsy
-non-invasive
-available
-Dx only
Flexible:
- visualization
- biopsy mucosa
- smaller biopsies
- minimally invasive
- more expensive
- less available
- Dx and occasional Tx
Surgery:
- palpation
- biopsy all layers
- bigger biopsies
- invasive
- most expensive
- available
- Dx and Tx
options for medical treatment of GI ulceration
Inhibit gastric acid secretion:
¡ Block H2 receptor – ranitidine, famotidine
¡ Block proton pump – omeprazole, pantoprazole
¡ Block intracellular cAMP – misoprostol
Neutralize gastric acids:
¡ Al(OH)3, Mg(OH)2, CaC03
¡ Limited use except in uremia
Protect cells:
¡ Sucralfate
Increase local prostaglandins:
¡ Misoprostol (synthetic PGE1 and PE2)
* Many beneficial effects (pH, mucus, blood flow)
significanace of helicobacter for gastritis
¡ H. pylori a major cause of gastritis and ulcers in humans (although many asymptomatic)
¡ Role in gastritis in dogs and cats?
¡ Vast majority of dogs asymptomatic
* >80% serologic positive
how to diagnose helicobacter GI? what is the ‘best’?
Cytology:
- Gastric brush cytology
¡ Least expensive
¡ Most practical, fastest turnaround
¡ More sensitive than urease or histopathology
Rapid urease test
Histopathology
Culture:
¡ Not routinely conducted
use of rapid urease test for helicobacter dianosis? how to tell number in sample? when may we see false + or -?
¡ Detects the presence of urease produced by Helicobacter in a biopsy
¡ Rate at which the gel changes from yellow to magenta is proportional to the number
of Helicobacter in the sample
¡ No colour change within 24 hours= negative test
¡ False positives can be due to presence of other urease producing bacteria
¡ False negatives due to patchy distribution
what does helicobacter look like with histopathology?
¡ Spiral bacteria (within the mucus covering the surface epithelium, the gastric pits,
glandular lumen and the parietal cells)
¡ Gastritis observed in infected dogs ««_space;H. pylori infected humans
¡ Modified Steiner’s silver stein
when will we consider helicobacter for gastitis?
¡ Rule-out other causes chronic vomiting
¡ If no other cause found + organisms
treatment for helicobacter
¡ Veterinary protocols adapted from humans
* Humans: amoxicillin, metronidazole, clarithromycin
* H2 blocker, proton pump inhibitor [Helicobacter proliferate in acid environment]
* Pepto-Bismol
Gastric neoplasia broad categories? always with vomiting?
¡ Adenocarcinoma
¡ Lymphoma
¡ Leiomyoma
¡ Leiomyosarcoma
¡ May occur without vomiting
BENIGN CAUSES OF CHRONIC VOMITING
¡ Eating too quickly
¡ Billious vomiting syndrome in dogs
> Vomiting in morning - otherwise fine
* Any age
* Add meal at bedtime
* Low fat diet
* Prokinetic drugs
What is delayed gastric emptying? delayed gastric emptying is often present with what? analagous to what?
Reduced/altered gastric motility
¡ Often present and expected with disorders causing acute vomiting
¡ Analogous to intestinal ileus
delayed gastric emptying can cause vomiting how long after feeding? what type of vomiting?
¡ Sometimes > 8-10 hours after feeding
¡ Sometimes projectile
what pyloric issues can lead to delayed gastric emptying?
¡ Congenital pyloric stenosis
* Brachycephalic dogs
* Siamese cats
¡ Acquired pyloric stenosis
* Idiopathic (small breed dogs)
* Chronic use of omeprazole
* Pancreatic gastrinoma (rare)
¡ Chronic foreign body
¡ Pyloric or antral tumour
DELAYED GASTRIC EMPTYING- DIAGNOSIS AND TREATMENT
¡ Barium study
¡ Abdominal ultrasound
¡ Endoscopy
- most useful for identifying foreign bodies
¡ Surgery
- Biopsy
- Response to pyloroplasty
