Gastro - Diseases of the Stomach Flashcards
What are gastric ulcers?
deep disruption of gastric mucosa down to the muscularis
What is a gastric erosion?
A superficial disruption of the gastric mucosa
What do the parietal cells of the stomach produce? What do their receptors respond to?
Hydrochloric acid
Respond to gastrin, Ach, and histamine
What is H+ role in gastric ulcers/erosions?
There is some type of disruption in the gastric mucosal barrier leading to a back-diffusion of H+ which ultimately the accumulation causes damage
What clinical signs are associated with gastric ulcers/erosions?
vomiting, hematemesis, abdominal pain (tucked up abdomen), melena, inappetance, anorexia, and ptyalism (over salivation)
What is found on PE in patients with gastric ulcers/erosions?
Pain on abdominal palpation, pale mm, melena on rectal exam
What can cause gastric ulcers/erosions?
Drugs, mucosal ischemia, CNS disease, renal disease, liver disease, and mucosal inflammation
What drugs can cause gastric ulcers/erosions?
NSAIDs and glucocorticoids
What diagnostic tests can be used for gastric ulcers/erosions?
Rectal exam for melena, CBC, biochemistry, urinalysis, diagnostic imaging, and GI endoscopy
What CBC abnormalities are associated with gastric ulcers/erosions?
anemia +/- regeneration
What will a high BUN on a patient with a suspected gastric ulcer/erosion indicate?
it may suggest GI hemorrhage
What are the treatment goals for gastric ulcers/erosion?
Correct the disease (GI or extra GI), give fluid/electrolytes, monitor the GI bleeding, decrease gastric secretions, and increase cytoprotection
What drugs are histamine H2 antagonists?
Cimetidine, ranitidine, and famotidine
What do histamine H2 antagonists do?
inhibit acid secretion on parietal cells
Histamine H2 antagonists have some efficacy against gastric ulcers/erosions, but what drugs are the best?
proton pump inhibitors (PPI)
What is the duration of action of famotidine?
48 hours
Which histamine H2 antagonist has prokinetic action?
ranitidine
What histamine H2 antagonist has the least hepatic inhibition? the greatest?
Least inhibition - famotidine
Greatest inhibition - cimetidine
What is sucralfate?
a cytoprotective drug
Why is reflux a problem?
because there are irritative agents in the reflux
What does sucralfate do?
Provides mucosal protection, inactivates pepsins, and promotes PGE
What disease processes is sucralfate effective in?
esophagitis, gastritis, and duodenitis
Why would you want to stagger sucralfate doses when using it with concurrent drugs?
because it may inhibit absorption
What drugs are proton-pump inhibitors?
Omeprazole (PO) and pantoprazole (IV)
What do proton-pump inhibitors do?
Inhibit H/K ATPase pump which reduces gastric volume/acidity
What is one major reason that proton-pump inhibitors are superior to H2 blockers?
because it is rare for them to have adverse effects
What disease processes should proton-pump inhibitors be your first chioce?
esophagitis or gastritis
What do mucosal PGE’s do?
Decreases H secretion, increases gastric blood flow, increases HCO3 production, and increases mucus secretion
What is the prostaglandin E1 analogue that is the drug of choice in cases of NSAID induced gastritis?
Misoprostil
Generally, how long is therapy for gastric ulcers/erosions?
14-21 days
What can cause delayed gastric emptying?
pyloric outflow obstruction or gastric hypomotility
What is the primary sign of delayed gastric emptying?
post prandial vomiting >8-10 hours after a meal
How is delayed gastric emptying diagnosed?
based on history, radiology, and gastroscopy
What will you see on contrast radiographs in a patient with delayed gastric emptying?
There will be filling defects
What is gastric dilation-volvulus (GDV)?
rotation of the stomach on its mesenteric axis with gastric distension
What breeds have a higher incidence of GDV?
giant and deep-chested breeds
What historical signs are associated with GDV?
acute onset of abdominal distention, retching/vomiting and collapse
What PE findings are associated with GDV?
Lethargy, abdominal distension, shock, +/- gastric intubation, increased abdominal girth, retching, ptyalism, increased respiratory effort, and poor circulation
What risk factors lead to GDV?
Deep chested, increased H:W ratio, increase in swallowed air, and decreased gastric emptying
What pathophysiologic changes does GDV cause?
Gastric distension, poor perfusion due to reduced CO, gastric mucosal ischemia, DIC due to vascular sludging, genesis of cardiac arrhythmias, and progressive respiratory depression
True or False: Passing a stomach tube rules out GDV
false
How is GDV diagnosed?
History, PE, and radiograph (confirms)
What will a radiograph show in a patient with GDV?
abnormal pyloric location and a double bubble appearance
What will CBC/biochemistry show in a patient with GDV?
Increased hematocrit (PCV), hypokalemia, and variable acid-base (acidosis usually)
What radiographic view should you always take when you suspect GDV?
right lateral view
How is a simple dilation managed?
Decompress the stomach with a stomach tube, +/- a gastric lavage, prokinetics to increase emptying, and observe for progression to GDV
What are the three major goals of therapy for GDV?
Gastric decompression, correction of metabolic and systemic abnormalities, and anatomic repositioning
If the lactate is less than 6, what is the chance of survival?
99% chance of survival
What is the procedure for anatomic relocation in GDV cases?
resection/gastropexy
What type of IV line is best for GDV treatment?
central IV line
Is fluid therapy needed for GDV cases?
yes - aggressive fluid therapy
When would you use bicarbonate in GDV cases?
if the patient is acidotic
When would you use antibiotics in GDV cases?
If the patient is septic or if there is a GI perforation
What would you use to treat for an arrhythmia or tachycardia in GDV cases?
Lidocaine and/or sotalol
What GDV risk factors are associated with mortality?
Delayed diagnosis, gastric necrosis, splenectomy, multiform PVC’s, large resection, and if the lactate is greater than 6mmol
With surgery, what is the percentage of mortality?
15%
There is a higher mortality rate if what happens?
gastric necrosis, perforation, or a splenectomy
What therapy is important to improve a patients prognosis?
nutritional therapy
What is the nutritional therapy recommended for GDV patients?
Fentanyl for pain management, small frequent feedings but no dry kibble, and prokinetics to empty the stomach
What are the three most common causes of intestinal obstruction?
foreign bodies, intussusception/volvulus/torsion, and intestinal neoplasia
Aside from the most common causes of intestinal obstruction, what else can cause it?
bowel incarceration, adhesions or strictures, and intramural lesions
What is the most common type of intestinal obstruction?
simple obstruction
What is occluded in a simple intestinal obstruction?
the lumen only
What happens to the vasculature in simple intestinal obstructions?
it remains intact
Where does distension occur in simple intestinal obstructions?
proximal to the obstruction
A strangulation obstruction is characterized by _________ vasculature.
compromised
What are the most common causes of strangulation obstructions?
volvulus, hernia, torsion, and intussusception
Where does intussusception typically occur?
Ileocolic and cecocolic junctions
Ileocolic and cecocolic intussusception is most common in dogs of what age?
dogs less than 3 months old
What clinical signs are seen with ileocolic and cecocolic intussussception?
tenesmus, fresh blood, and vomiting
How will intussusception appear on radiographs?
dilated bowl loops
How will intussusception appear on ultrasound?
There will be classic target lesions
How is intussusception treated?
resection/reduction +/- gut plication
What common clinical signs are associated with obstruction?
acute vomiting, anorexia, and depression predominate
What other systemic signs may patients with obstruction have?
dehydration, diarrhea, pain, and abdominal distension
What is the classic cause of proximal obstruction?
foreign body
When will the onset of clinical signs begin with proximal obstruction and what are they?
Acute; intense clinical signs, severe vomiting and dehydration
Is distal obstruction acute or chronic?
chronic
What clinical signs are associated with distal obstruction?
vague, intermittent signs
What lesions is distal obstruction seen with?
intestinal mass lesions
How is obstruction diagnosed?
abdominal palpation and radiographs
What will intussusception feel like on abdominal palpation?
a sausage-like structure
What will you see on a radiograph as evidence of obstruction?
gas or fluid distension - luminal opacity
Plication with linear foreign body
If there is a perforation due to obstruction, what procedure would you want to do?
abdominocentesis
If there is an esophageal or gastric foreign body, what diagnostic procedure would you want to do?
GI endoscopy
