Gastrointestinal Flashcards
(101 cards)
Most common asked or tested physiological changes as a result of cirrhosis with progressive liver fibrosis
- Formation of a high-resistance system (portal hypertension), results in the following:
- ⬆Nitrous oxide and vasodilatory factors (from bacterial products [endotoxin] accumulated due ⬇host defenses, ⬆portosystemic shunting➡⬇toxin clearance)
- Splanchnic vasodilation➡⬇systemic vascular resistance, compensatory ⬆HR, CO▶Hyperdinamic circulation
- (+) RAAS and ADH➡Na and H2O retention
Most specific and sensitive test to evaluate celiac disease
IgA anti-tissue transglutaminase (anti-tTG) and anti-endomysial antibodies (anti-EMA)►jejunal mucosal damage
*Serum antigliadin antibody no longer used routinely►lower sensitivity and specificity
How do you diagnose celiac disease without small bowel biopsy?
Positive serology (anti-tTG, anti-EMA) + confirmed dermatitis herpetiformis by Bx
*Small bowel biopsy is the most accurate test
Most accurate test of celiac disease and its common findings
Small bowel biopsy→blunting of distal duodenal and/or proximal jejunal villi, crypt hyperplasia, intraepithelial lymphocytosis
*Always necessary to exclude bowel wall lymphoma
How do you differentiate corticosteroid-induced vs statin-induced myopathy?
- Corticosteroid induced→muscle enzymes normal, EMG normal. Lower extremity weakness and proximal atrophy. No correlation with dosage or duration.
- Statin-induced→↑↑ CPK ten times upper limit, weakness
Enough findings to diagnose Wilson disease. Most accurate test to Dx.
- Low ceruloplasmin concentration (<20 mg/dL), Keyser-Fleischer rings on slit-lamp examination
- Liver Biopsy
How do you differentiate between Rotor vs Dubin-Johnson syndrome?
- Dubin-Johnson→lack elevation of urinary coproporphyrins, has darkly pigmented liver
- Rotor→milder in presentation without black liver, ↑urinary coproporphyrins
When do you evaluate for liver transplantation?
- Decompensated liver failure
- Portal hypertension
- ↓Synthetic function (variceal hemorrhage, ascites, encephalopathy)
*Liver biopsy→evaluate extent of structural damage to the liver and candidacy for liver transplantation
Esophagus manometry results in scleroderma. How do you suspect esophageal compromise?
- ↓Lower esophageal sphincter pressure, ↓esophageal peristalsis
- Gastroesophageal reflux disease (GERD) and dysphagia
What is motility-type dysphagia? Example of disease with that.
- Difficulty with liquids and solids from the onset of symptoms
- Diffuse esophageal spasm
Test to confirm lactose intolerance
Lactose hydrogen breath test➡⬆hydrogen levels after lactose ingestion (bacterial carbohydrate metabolism)
Gradual luminal narrowing of the esophagus after many years of gastroesophageal reflux disease (GERD).
Peptic esophageal stricture
Diagnostic test for gastrointestinal angiodysplasia
Mesenteric angiography▶Dilated, slow-flowing vein in the colon
Treatment for gastrointestinal angiodysplasia
Endoscopic ablation→cauterization or laser coagulation (if fails, surgical removal of affected bowel)
Most common cause of lower GI bleeding
- Diverticulosis
2. Angiodysplasia
How do you screen for factitious diarrhea due to laxative abuse?
Stool screen for diphenolic (eg, bisacodyl) or polyethlynele-containing laxatives
How do you confirm the diagnosis of factitious diarrhea due to laxative abuse?
Colonoscopy➡Melanosis colia▶dark brown discoloration of the colon with pale patches of lymph follicles (alligator skin)
Useful tests to rule out factitious diarrhea
- Stool osmolality: Normal➡290 mOsm/Kg (plasma). Hypoosmolality➡addition of water or other dilute fluid. Hyperosmolality➡addition of concentrated fluid )urine)
- Stool electrolytes: ⬆Mg and PO4▶overuse of saline osmotic laxatives
- Stool osmotic gap: Osmotic laxatives (lactulose, polyethyleneglycol)▶⬆osmotic gap diarrhea. Senna and bisacodyl▶⬇osmotic gap secretory diarrhea
Where is the most common location of the VIPoma? How do you confirm the diagnosis?
- Pancreatic tail
- VIP level >75 pg/mL
Most common electrolytic disturbances in VIPoma syndrome
- VIPoma syndrome (pancreatic cholera)►secretory, watery diarrhea and ↓ gastric acid secretion→hypokalemia and hypo or achlorhydria
Colonoscopy recommendations for colon cancer screening in inflammatory bowel disease
- 8-10 years after diagnosis (12-15 years if only left colon)
- Repeat every 1-3 years
Colonoscopy recommendation for colon cancer screening in lynch syndrome (HNPCC)
- Age 20-25 years
- Repeat every 1-2 years
Colonoscopy recommendations for colon cancer screening in classic familial adenomatous polyposis
- Age 10-12 years
- Repeat anually
Colonoscopy recommendations for colon cancer screening family history of adenomatous polyps or CRC
- Age 40 or 10 years before the age of diagnosis of the relative
- Repeat every 5 years