Exam 4- Clinical Correlations Flashcards
Indigestion, loss of appetite, abd pain, “oily” diarrhea, and ulcers on endoscopy eval might be concerning for what?
Zollinger-Ellison syndrome
What might lab values for Zollinger-Ellison syndrome show?
Elevated serum gastrin level, elevated gastric H+ secretion
If pt with Zollinger-Ellison synrome has a mass on the pancreas identified as a gastrinoma, what is the management? (2)
Omeprazole (proton pump inhibitor) prior to surgery, then laparoscopic surgery
What is the cause of the high levels of gastrin in Zollinger-Ellison syndrome?
Gastrinoma NOT controlled by feedback mechanisms
What is the result of high levels of gastrin in Zollinger-Ellison syndrome? (3)
Hypersecretion of gastric acid, hypertrophy of gastric mucosa, ulcers
What test is used involves infusion of a gastrin analogue while the stomach contents are sampled using a nasogastric tube?
Pentagastrin stimulation test
In healthy individuals, pentagastrin stimulates H+ by parietal cells to what levels?
3x higher than basal secretion
Why would a pentagastrin stimulation test likely have no effect on a pt with Zollinger-Ellison syndrome?
H+ secretion already maximal
For unknown reasons, secretin directly stimulates gastrin release by gastrinoma cells, but not what type of cells?
Antral G cells
What is the result of a secretion stimulation test in a pt with Zollinger-Ellison syndrome?
Serum gastrin increases (N response = decreased or unchanged)
What is the cause for “oily” stools (steatorrhea) in a pt with Zollinger-Ellison syndrome?
Inactivation of pancreatic lipase by low duodenal pH
Loss of more than 100cm of terminal ileum will disrupt what process?
Enterohepatic circulation of bile salts
What might be the cause of a pt losing bile salts faster than the liver can replace them and what will this result in?
Ileal resection, lipid digestion greatly impaired
Why would a pt with an ileal resection present with oily, pale, and foul smelling stool?
Result of bile salt depletion is steatorrhea (undigested fat in stool)
Bile salts stimulate Cl- and water secretion in the colon, casuing what clinical presentation? (ileal resection)
Chronic diarrhea
What is a cationic resin that binds bile salts and results in their excretion?
Cholestyramine
Cholestyramine was originally used to treat what condition?
Hypercholesterolemia (loss of bile salts stimulates hepatic synthesis of new bile salts from cholesterol)
How does cholestyramine reduce diarrhea?
Binds bile salts so they do not stimulate Cl- and fluid secretion by the colon
What is the largest and most structurally complicated vitamin and is aka cobalamin?
Vit B12
Why must a pt with an ileal resection have Vit B12 injections?
Intrinsic factor B12 complex is normally absorbed by the ileum
Pt presenting with “acid indigestion” described as burning and dull ache in her stomach, what might you be concerned for?
H.pylori infection/ peptic ulcer disease
The results of a serological test and a C-urea breath test consistent with H.pylori might be concerning for what disease?
Peptic ulcer disease
What is used to treat a pt with peptic ulcer disease from H. pylori? (2)
Antibiotic and proton pump inhibitor (Omeprazole)
What is defined as an ulcerative lesion of the gastric or duodenal mucosa caused by erosive and digestive actions of H+ and pepsin on the mucosa (which is ordinarily protected by mucous and HCO3-)?
Peptic ulcer disease
What pathogen is a G- bacterium that colonizes the gastric mucosa and can lead to gastric and duodenal ulcers, usually in the antrum?
H. pylori
What is requied for peptic ulcer formation? (3)
- loss of protective mucous barrier, 2. excessive H+ and pepsin secretion, 3. combo of the two
What factors outside of H+ and pepsin can lead to peptic ulcer disease? (5)
H. pylori infection, NSAIDs, stress, smoking, alcohol
What virulence factors of H. pylori allows for their destruction and survival in the stomach? (2)
Cytotoxins break down protective mucous. Releases urease which converts urea to NH3. NH3 to protonated to NH4 leading to an alkalinization of their local enviroment allowing bacteria to survive
How does H. pylori cause a duodenal ulcer?
Infection and inflammation leads to decreased HCO3- secretion
How can H. pylori infections of peptic ulcer disease be diagnosed? (3)
Serologic tests for antibodies, C-urea breath test (measurement of CO2 produced by H.pylori), endoscopic bx
What is the treatment for an H.pylori infection? (2)
Abx + proton pump inhibitor (Omeprazole)
