Gastroenterology Flashcards
What are the 2 first line therapy options for an H. pylori infection?
- Triple therapy: PPI + clarithromycin + amoxicillin or metronidazole
- Bismuth-containing quadruple therapy: PPI or an H2-receptor antagonist + bismuth + tetracycline + metronidazole
What is a hepatic hydrothorax?
A transudative pleural effusion caused by small defects in the diaphragm (usually right side because less muscular) that can allow ascites to pass into the pleural space in patients with ascites (e.g. cirrhotic patient)
What are the diagnostic 3 criteria for acute liver failure? (helps to differentiate from acute hepatitis)
Severe acute liver injury (ALT & AST often >1000)
Signs of hepatic encephalopathy
Synthetic liver dysfunction (INR >1.5)
How is SAAG calculated and what does it signify?
Serum-ascites albumin gradient (subtract ascites albumin from serum). If SAAG ≥1.1 g/dL, it indicates portal hypertension for cause of ascites
What are gastrointestinal symptoms of a glucagonoma?
Diarrhea, anorexia, abdominal pain, and occasional constipation
What are risk factors for acalculous cholecystitis?
Severe trauma or recent injury (e.g. severe burns), recent surgery (particularly cardiopulmonary, aortic, or abdominal), prolonged fasting or TPN, and critical illness (e.g. sepsis, ICU)
How does the D-xylose test help distinguish celiac disease vs pancreatic insufficiency as a cause of malabsorption?
-Pt is given oral D-xylose and urinary excretion is measured
Celiac disease: Urinary D-xylose will be low (monosaccharide is not absorbed well).
Pancreatic insufficiency: D-xylose absorption is unaffected by pancreatic enzymes so will have normal level in urine
What vaccines are recommended for chronic liver disease in patient under 65?
Tdap (every 10 years), influzena (annually), PPSV23 once (then revaccinate sequentially with PCV13 & PPSV23 at age 65), hep A, and hep B
What is angiodysplasia?
Causes painless GI bleeding and is characterized by dilated submucosal veins and AV malformations. Increased incidence after age 60. Most common in R colon and is associated with advanced renal disease and von Willebrand disease, and is more common in patients with aortic stenosis.
What are possible signs and symptoms of toxic megacolon?
Fever, abdominal distension, leukocytosis, hypotension, tachycardia, altered mental status, peritonitis, and electrolyte abnormalities
What test should you do if you suspect toxic megacolon?
Abdominal x-ray
What is the treatment of toxic megacolon?
Bowel rest, nasogastric suction, and either corticosteroids with broad spectrum antibiotics (due to IBD) or antibiotics targeted at C. diff
What measures should be considered for primary prophylaxis in patients with esophageal varices?
A nonselective beta-blocker such as propranolol or nadolol or variceal banding (preferred for large varices)
What are common causes of secretory diarrhea?
Bacterial infections (e.g. Vibrio cholera), viral infections (e.g. rotavirus), congenital disorders of ion transport (e.g. CF), early ileocolitis, and postsurgical changes or after bowel resection or cholecystecomy (when unabsorbed bile acids reach the colon and result in direct stimulation of luminal ion channels)
How is the stool osmotic gap used?
A high osmotic gap (SOG > 125) indicates osmotic diarrhea. SOG <50 indicates secretory.
SOG = (plasma osmolality) - 2(stool sodium + stool potassium)
