Gastroenterology 4 Flashcards
What is Acalculous cholecystitis and what is it caused by?
Acute cholecystitis not due to gallstones.
Caused by gall bladder ischemia and stasis (commonly in critically ill patients).
AIDS Cholangiopathy is a result of what?
Chronic infection involving biliary tree, usually involving Cryptosporidium (most common) and CMV.
What is Ascending Cholangitis?
Stone blocks flow of bile (cholestasis) → GI bacteria ‘ascend’ in biliary tree and cause infections.
What is the clinical triad and pentad seen in Ascending Cholangitis?
Charcot’s triad: Fever, abdominal pain, jaundice.
Reynolds pentad: Fever, abdominal pain, jaundice, confusion, hypotension. Indicates sepsis and shock from infection.
What 3 diagnostic labs are seen in Ascending Cholangitis?
↑ WBC, ↑ Alk Phos»_space; ↑ AST/ALT, ↑ conjugated bilirubin (and total).
What are 3 common bacteria that cause Ascending Cholangitis?
Gram negatives: E. coli, Klebsiella, Enterobacter.
What is a rare cause of Ascending Cholangitis? What is a hallmark of this infection?
Clonorchis sinensis (Chinese liver fluke found in infected fish).
Will see peripheral eosinophilia due to helminth infection.
What are 2 treatment therapies for Ascending Cholangitis?
Antibiotics with Gram negative and anaerobic coverage.
Examples include Ampicillin-sulbactam and Ciprofloxacin-Metronidazole.
What is Endoscopic retrograde cholangiopancreatography (ERCP)?
Combination of endoscopy and fluoroscopy, can inject dye into bile duct to visualize obstruction or use tools on endoscope to pull out stone.
What is Gallstone ileus?
Massive gallstone erodes through gallbladder wall → Creates fistula with small intestine → large stone can cause bowel obstruction at ileocecal valve.
What is a key radiologic imaging finding seen in Gallstone ileus?
Air in the biliary tree.
What can obstruction of common bile duct by stone lead to?
Cholangitis or acute pancreatitis.
What is gallbladder carcinoma?
Rare adenocarcinoma from chronic inflammation.
Risk factors include chronic cholecystitis (untreated gallstone disease) and chronic salmonella infection: S. typhi can remain in carrier state in gall bladder.
What is Biliary Atresia? What are 3 symptoms seen?
Idiopathic biliary obstruction in neonates.
Symptoms include jaundice, pale stools, dark urine.
What may ultrasound of a patient with Biliary atresia reveal?
Gallbladder absent or abnormal, absence of common bile duct.
What is the treatment for Biliary atresia?
Kasai procedure: Create conduit for bile drainage using small intestine.
What is Biliary Cirrhosis?
Old term used for liver damage due to biliary obstruction i.e. gallstone, pancreatic cancer.
What is Primary Biliary Cirrhosis?
Autoimmune disorder, T-cells attack interlobular bile ducts → Granulomatous inflammation.
Primary Biliary Cirrhosis is more common among which gender?
Women.
What are the 2 most common initial symptoms in Primary Biliary Cirrhosis?
Fatigue and pruritus (often precedes jaundice, may be worse at night).
What is a key symptom of Primary Biliary Cirrhosis?
ITCHING!!!
What 2 antibodies are commonly present in Primary Biliary Cirrhosis?
Anti-mitochondrial antibodies (hallmark), Anti-nuclear antibodies.
What are 3 abnormal LFTs seen in Primary Biliary Cirrhosis?
Markedly elevated alkaline phosphatase, may see mild elevations AST/ALT, ↑ bilirubin occurs late.
What is a key non-liver lab finding in Primary Biliary Cirrhosis?
Serum lipids may be markedly elevated.
Xanthomas may be present.
What will imaging show in Primary Biliary Cirrhosis?
Absence of biliary obstruction.
What is a typical case presentation of Primary Biliary Cirrhosis?
Woman with itching, fatigue, markedly elevated Alk Phos, positive anti-mitochondrial antibodies.
What are 2 treatments for Primary Biliary Cirrhosis?
Ursodeoxycholic acid: Only effective therapy, replaces endogenous bile acids and prevents disease progression.
Liver transplant.
Primary Biliary Cirrhosis is associated with what other condition?
Other autoimmune disorders, most common is Sjogren’s.
What is Primary Sclerosing Cholangitis?
Autoimmune disorder that leads to inflammation, fibrosis, strictures in biliary tree.
Primary Sclerosing Cholangitis is strongly associated with what other condition?
Ulcerative colitis.
What are 3 clinical features of Primary Sclerosing Cholangitis?
Strictures obstruct bile flow → Symptoms of biliary obstruction: RUQ pain, fatigue, jaundice.
What 3 abnormal LFTs are seen in Primary Sclerosing Cholangitis?
Elevated alkaline phosphatase, elevated conjugated bilirubin, usually mildly elevated AST/ALT.
What 2 antibodies are commonly seen/elevated in Primary Sclerosing Cholangitis?
Elevated IgM levels, positive p-ANCA.
What is a histopathology finding in Primary Sclerosing Cholangitis?
Periductal fibrosis (‘Onion skin’ fibrosis of bile ducts).
What is used to confirm diagnosis of Primary Sclerosing Cholangitis? What is the finding?
Cholangiogram: ERCP, MRCP (MRI cholangiography).
Biliary strictures and dilations (‘beading’) is seen.
What are 2 treatments for Primary Sclerosing Cholangitis?
Endoscopic therapy: Dilation or stenting of strictures in bile ducts.
Liver transplant.
Patients with Primary Sclerosing Cholangitis have an increased risk for what?
Cholangiocarcinoma.
What is Cholangiocarcinoma? Symptoms?
Cancer of bile duct epithelial cells.
Symptoms arise from bile duct obstruction.
What are 2 risk factors for Cholangiocarcinoma?
Primary sclerosing cholangitis (ulcerative colitis), Clonorchis sinensis (Chinese liver fluke).
What is the difference between Gastritis, Erosion, and Ulcer?
Gastritis: inflammation of mucosa.
Erosion: loss of epithelial layer, may extend into muscularis mucosa but will not break through. Ulcer: loss of mucosal layer.
In what 2 regions are ulcers mostly found in the GI tract?
Stomach, duodenum.
What type of infiltrate is seen on biopsy in Acute and Chronic gastritis?
Acute: Neutrophil.
Chronic: Lymphocytes, plasma cells, macrophages.
What are the 2 common causes of Chronic gastritis?
Autoimmune (type A), H. pylori (type B).
What are symptoms of dyspepsia?
Dyspepsia = indigestion.
Symptoms include nausea, vomiting, loss of appetite, abdominal pain.
What are symptoms of acute gastritis? They are often worsened by…
Dyspepsia, food.
What are the 2 underlying mechanisms that lead to acute gastritis?
Excess acid, loss of protection (mucous, bicarbonate).
ACh and histamine [stimulate/inhibit] acid production.
Stimulate.
Prostaglandins [stimulate/inhibit] acid production.
Inhibit.
Where are parietal cells found in the stomach?
Fundus and body.
What are 4 common causes of acute gastritis?
NSAIDS: block prostaglandin production, increases acid production.
Alcohol: directly damages mucosa, Chemotherapy: inhibits epithelial cell replication, H. Pylori.
What is Curling’s ulcer?
Occurs in burn patients.
Loss of skin → loss of fluids, decrease plasma volume → hypotension → decreased mucosal perfusion → mucosal damage.
Any patient with extensive burns are usually put on what drug to prevent Curling’s ulcer?
PPI.
What are Cushing’s ulcers caused by?
Increased intracranial pressure i.e. tumor, hemorrhage → increased vagal stimulation → ↑ Ach to stomach → Excess acid production, gastritis/ulcer.
What are Stress ulcers caused by?
Shock, sepsis, trauma → ↓ mucosal perfusion → loss of protective barrier of mucous/bicarb.
What is used as prophylactic therapy for Stress ulcers?
Proton pump inhibitors (offered to all ICU patients).
Patients with Chronic gastritis are often _______ until complications develop.
Asymptomatic.
Autoimmune gastritis is also known as?
Pernicious anemia.
Pernicious anemia affects what part of the stomach?
Body/fundus (where parietal cells are located).
Autoimmune gastritis is more common in [M/W].
Women.
Pernicious anemia is associated with what other disease?
Gastric adenocarcinoma.
What is the most common cause of Chronic gastritis?
H. pylori.
What type of bacteria is H. pylori?
Gram negative rod.
H. pylori causes ulcers in what region of the GI tract?
Antrum of stomach.
An important virulence factor of H. pylori is ______. What is the function and what does it cause?
Urease.
Hydrolyzes urea → produces ammonium (alkaline) → protects bacteria from stomach acid and forms ammonium chloride which damages stomach.
H. pylori is associated with what 2 malignancies?
Gastric Adenocarcinoma, MALT lymphoma (highly associated): B cell cancer.
What are 3 ways to diagnose H. pylori?
Biopsy, Urea breath test, Stool antigen.
How is the urea breath test performed?
Patients swallow urea with isotopes (carbon-14 or carbon-13).
Detection of isotope-labelled carbon dioxide in exhaled breath indicates presence of urease.
What does the ‘triple therapy’ for H. pylori consist of?
Proton pump inhibitor, Clarithromycin, Amoxicillin/Metronidazole.
What is Metaplastic Atrophic Gastritis? What is a key pathology finding?
Chronic gastritis → intestinal metaplasia.
Key path finding: Goblet cells appear in stomach.
Solitary ulcers in peptic ulcer disease are found in what 2 locations? Which is more common?
Antrum of stomach (~10%), Proximal duodenum (~90%).
What are 3 risk factors for peptic ulcer disease?
NSAIDs, H. pylori infection, Smoking.
Duodenal ulcers are almost always related to _____. Why?
H. pylori.
Can increase gastric acid production.
What is a rare cause of Duodenal Ulcers? How does it present?
Zollinger-Ellison Syndrome.
Often multiple ulcers in distal duodenum or jejunum.
Epigastric pain from Duodenal Ulcer [improves/worsens] with food. Why?
Improves, meal stimulates secretion of bicarb.
Duodenal Ulcers are [commonly/almost never] cancerous.
Almost never.
Brunner’s Gland Hypertrophy is seen in what condition?
Peptic ulcer disease.
What are 3 complications of duodenal ulcers?
Upper GI Bleeding: More common when located posteriorly, Pancreatitis, Perforation.
When duodenal ulcers cause bleeding, what is the usual source?
Gastroduodenal artery.
Upper GI bleeding is bleeding above what landmark?
Ligament of Treitz.
What are 2 symptoms of Upper GI bleed?
Melena (lower GI bleed results in Hematochezia), Hematemesis.
Gastric or duodenal Ulcer perforation leads to what finding on CXR?
Air under diaphragm (pneumoperitoneum).
What is the usual source of bleeding in duodenal ulcers?
Gastroduodenal artery
Upper GI bleeding is bleeding above what landmark?
Ligament of Treitz
What are 2 symptoms of Upper GI bleed?
- Melena (lower GI bleed results in Hematochezia)
- Hematemesis
Gastric or duodenal ulcer perforation leads to what finding on CXR?
Air under diaphragm (pneumoperitoneum)
Where are gastric ulcers commonly located in the stomach?
Lesser curvature
Gastric ulcer rupture causes bleeding from what artery?
Left gastric artery
Does abdominal pain from gastric ulcer improve or worsen after meals?
Worsens, food stimulates acid release
What are 2 causes of gastric ulcer?
- H. Pylori
- Adenocarcinoma (often biopsied)
What are 2 complications of gastric ulcers?
- Perforation
- Upper GI bleeding
What is the treatment for gastric/duodenal ulcers?
- Proton pump inhibitors are therapy of choice
- Treat H. pylori if indicated
Proton pump inhibitors are often used empirically for dyspepsia symptoms in what conditions?
GERD, gastritis, ulcers
What percentage of gastric carcinomas are adenocarcinomas?
95%
What is the clinical presentation early in gastric carcinoma?
- Usually asymptomatic until advanced
- Non-specific symptoms i.e. weight loss, abdominal pain, early satiety
What are the 2 types of gastric carcinoma?
Intestinal, Diffuse
Intestinal gastric carcinoma grossly appears as what? Where is it commonly found?
- Large ulcer with irregular margins
- Lesser curvature of stomach
Intestinal gastric carcinoma results from what?
Intestinal metaplasia due to H. pylori, autoimmune gastritis
Intestinal gastric carcinoma is more common among what demographic?
Older men
What are 4 risk factors for intestinal gastric carcinoma besides chronic gastritis?
- Smoking
- Alcohol consumption
- Nitrosamines: found in smoked meats, linked to cancer by case control studies
- Type A blood: mechanism unclear
What is a morphologic finding in diffuse type gastric carcinoma? What is a common symptom?
- Stomach diffusely thickened (linitis plastica), made up of gastric mucosa cells
- Early satiety
What special type of cells are found in diffuse gastric carcinoma?
Signet ring cells, mucin forms and nucleus is pushed to periphery
What is the most common site of metastasis of gastric carcinoma?
Liver
Gastric adenocarcinoma is associated with what 2 skin findings?
- Acanthosis Nigricans
- Leser-Trelat sign: ‘Explosive onset’ of multiple itchy seborrheic keratoses
Leser-Trelat sign is associated with many malignancies, which is the most common?
Gastric adenocarcinoma
What are 2 nodular findings in gastric carcinoma?
- Virchow’s node: Left supraclavicular node (drains stomach)
- Sister Mary Joseph nodule: Metastasis to periumbilical region, palpable on exam
What is a Krukenberg tumor? What cells are often seen on pathology?
- Bilateral ovarian tumor secondary to metastasis from another site, most common from gastric adenocarcinoma
- Signet cells often seen on pathology
What percentage of patients with dyspepsia have an organic cause?
25%
What are the organic causes of dyspepsia?
Gastritis, ulcers, cancer, H. Pylori
What is the next step in diagnostics for patient with dyspepsia +/- Age>55, alarm symptoms (weight loss, early satiety)?
Endoscopy
What is hypertrophic gastropathy?
Rare disorder characterized by enlarged rugal folds, caused by hyperplasia
What is Menetrier’s disease? What does this lead to?
Hyperplasia of mucous cells due to unknown cause, leading to excessive gastric mucous secretions, loss of acid, and protein loss (hypoalbuminemia → edema, facial swelling)
Menetrier’s disease is more common in which gender?
Men (3:1 ratio)
Menetrier’s disease can lead to what other disease?
Gastric adenocarcinoma
What are some clinical manifestations of fat malabsorption?
- Steatorrhea
- Pale if bile is absent (no bilirubin)
- Voluminous stools
- Greasy, foul smelling stools that float
- Loss of fat soluble vitamins
What is a clinical manifestation of carbohydrate malabsorption?
Watery diarrhea
What is a clinical manifestation of protein malabsorption?
Edema (loss of albumin)
What are the different types of diarrhea?
Steatorrhea, Inflammatory, Watery: Secretory, osmotic
How do you calculate stool osmotic gap? How do you interpret this?
290 - (2[Na]+2[K])stool
Osmotic gap >50 = osmotic diarrhea; Osmotic gap <50 = secretory causes
What is celiac disease? What is the mechanism of disease?
Autoimmune disease triggered by gluten exposure, leads to destruction of small intestinal villi
Gluten is a combination of what 2 compounds?
Gliadin and Glutenin
What is the pathogenic component of gluten? Why?
Gliadin is deamidated via tissue transglutaminase (tTG) → Deamidated gliadin is immunogenic
What genes are associated with celiac disease?
HLA-DQ2 and HLA-DQ8
What are 3 histological features seen in celiac disease?
- Blunting of villi
- Crypt hyperplasia
- Lymphocytes in lamina propria
Celiac disease is common in what demographic?
Whites of northern European descent
What are 3 antibodies seen in celiac disease? Which is most accurate?
- Anti-gliadin (rarely tested – poor accuracy)
- Anti-tissue transglutaminase
- Anti-endomysial
- IgA endomysial and tTG have highest accuracy, IgG testing can also be done if patient is IgA deficient
What are 3 key diagnostic tests for celiac disease?
- Biopsy
- IgA levels
- Anti-tTG
What area of the GI tract is most commonly affected by celiac disease?
Duodenum
What are 4 symptoms of celiac disease?
- Flatulence, bloating, Steatorrhea
- Iron deficiency anemia
What are 3 complications associated with celiac disease?
- Small ↑ risk small bowel malignancy (rare condition)
- Adenocarcinoma
- Enteropathy-associated T-cell lymphoma (EATL)
Celiac patient adherent to gluten-free diet with worsening symptoms is suggestive of what?
Cancer
What is dermatitis herpetiformis? What is it caused by?
- Herpes-like lesions on skin associated with celiac disease
- Caused by IgA deposition in dermal papillae
What is tropical sprue? Where does it occur?
- Malabsorption due to unknown infectious agent, leads to blunting of villi
- Occurs in the tropics (Caribbean)
What is a key difference between tropical sprue and celiac disease?
Different location
- Celiac: Duodenum most common
- Tropical: Entire small bowel affected
Celiac disease and tropical sprue may be associated with what deficiency?
- Celiac disease: iron deficiency anemia
- Tropical sprue: Folate/B12 deficiency
How does a typical case of tropical sprue present?
Patient is a traveler to tropics with chronic diarrhea and malabsorption
Tropical sprue should be treated with what?
- Antibiotics (usually tetracycline)
- Folate supplementation
What is Whipple disease?
- Caused by Tropheryma whipplei
- Systemic infection that involves small intestines, joints, brain, heart
What type of bacteria is Tropheryma whipplei?
Gram-positive rod
Whipple’s disease is most common in what demographic?
White, European men
What are the 4 cardinal features of Whipple’s disease? What are 4 other features seen?
- Diarrhea
- Abdominal pain
- Weight loss
- Joint pains (migratory arthralgias large joints)
- Mesenteric lymphadenopathy
- Hyperpigmentation
- Confusion with CNS involvement
- Culture negative Endocarditis
How is Whipple’s disease diagnosed? What is the classic finding?
Biopsy of small intestine: PAS positive foamy macrophage seen in lamina propria
What is the treatment for Whipple’s disease?
Ceftriaxone (different treatments for extra-intestinal disease)
Lactose is composed of what molecules?
Galactose and glucose
Lactose is digested by what?
Brush border enzyme lactase
Failure to digest lactose leads to what?
High volume, watery diarrhea
What are the 3 causes of lactose intolerance? Which is most common?
- Lactase non-persistence (most common): Enzyme levels fall with aging
- Congenital lactase deficiency (rare)
- Secondary deficiency due to mucosal injury i.e. viral infection, Celiac’s
What brush border enzyme is first lost following GI illness? Why?
Lactase, due to distal location on villi
How is lactose intolerance often diagnosed? What 2 diagnostic tests can be done?
- Often clear from history
- Lactose breath hydrogen test
- Lactose tolerance test (rarely done)
How to perform lactose breath hydrogen test? What do the test results mean?
- Patient ingests lactose then measure exhaled hydrogen level
- If lactose intolerant, bacteria will ferment lactose → ↑ Hydrogen
How to perform the lactose tolerance test? What do the test results mean?
- Monitor blood glucose level after lactose consumption
- Should rise if lactose → galactose and glucose
There is usually a small or large amount of organisms in the small intestines?
Small (should be nearly sterile)
Bacterial overgrowth in the small intestine can cause what?
Malabsorption (bloating, flatulence, abdominal discomfort, chronic diarrhea, vitamin deficiencies)
What are 2 causes of bacterial overgrowth in small intestines?
- Altered motility: diabetes mellitus (enteric nerve damage), scleroderma
- Partial/intermittent obstruction: adhesions, Crohn’s disease
What are 2 diagnostic tests used for bacterial overgrowth in small intestines?
- Jejunal aspirate (gold standard): not commonly done
- Lactulose test: laxative, bacteria will metabolize some into H+ (high H+ = bacterial overgrowth)
What is the treatment for bacterial overgrowth in small intestines?
Antibiotics
What are the 3 underlying mechanisms of increased fat malabsorption?
- Loss of bile (liver, biliary disease)
- Loss of pancreatic enzymes
- Loss of small bowel (resection)
What is the fecal fat test?
- Stool collected over 1-3 days
- Amount of fat measured, Normal <7 grams per day
What is the D-xylose test? How is it performed?
- Tests carbohydrate absorption small intestine
- After fasting, pt ingests D-xylose (monosaccharide absorbed in intestine, no enzyme required) → D-xylose then measured in serum/urine
- Intact mucosa = rise in D-xylose seen
What 2 tests can be used to diagnose sugar malabsorption?
- Stool pH: most sugars cause acidic pH
- Clinitest: detects undigested sugars, works best in children
What is the clinical presentation of acute pancreatitis?
- Epigastric pain, classically radiating to back
- Nausea/Vomiting
What are the 2 most common triggers for acute pancreatitis?
Gallstones, alcohol (triggers release of pancreatic enzymes, exact mechanism unclear)
What are 2 classic physical exam findings seen in acute pancreatitis? These findings are also found in what condition?
Cullen’s sign: periumbilical hemorrhage
Grey Turner’s sign: flank hemorrhage
Due to spread of necrosis from enzyme-induced damage; Ruptured ectopic pregnancy
