Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
Malabsorption
|
Impaired absorption of individual or multiple nutrients caused by the pathologic disruption of the normal physiological processes of digestion and intestinal transport
|
|
general Sx of malabsorption
|
Diarrhea- CHO, protein, fat
Steatorrhea-fat Weight Loss > 10% (calorie loss) Bloating, gassiness, flatulence-sugars |
|
Specific Sx of malabsorption
|
Peripheral edema-protein
Pica; symptoms of anemia -iron, B12, folate Neuropathy-B12 Night blindness-Vit A Accelerated osteoporosis-Vit D Ca++ |
|
Causes of Malabsoprtion (3)
|
Disaccharaide malabsorption, Maldigestion (slective fat malabsorption), global malabsorption.
|
|
Disaccharide malabsorption
|
Lactase Deficiency (common)
Fructose Intolerance (uncommon) Sucrase Deficiency (rare) |
|
Makdigestion (selective fat malabsorption)
|
Gastric resection or bypass
Bile salt deficiency - ileal resection/disease, SIBO Pancreatic Insufficiency |
|
Global malabsorption (CHO, protein, fat)
|
Short Bowel Syndrome
Mucosal Disease - Crohn's, Celiac, Whipple's, amyloidosis, lymphoma, radiation enteritis |
|
Clues from the Hx that lead to malabsorption
|
GI Surgery
Ulcer operations (esp. vagotomy & antrectomy) Gastric resection or bypass Cholecystectomy Small bowel resection (esp. terminal ileum) Right colon resection (esp. ileo-cecal valve) Pancreatitis or Hx of heavy EtOH abuse Abdominal or pelvic irradiation Collagen vascular disease |
|
Lactose Intolerance
|
Most common cause of chronic diarrhea in USA
Primary Absence of the lactase persistence SNP Highest incidence in persons of Asian, Native-American, and African-American ancestry Secondary Aging Post-infectious (enterovirus) Chemotherapy Celiac disease, Tropical Sprue, Giardiasis Bacterial Overgrowth Rapid transit syndromes |
|
Dx and Tx of lactose intolerance
|
Diagnosis
Presumptive Trial of a low-lactose or lactose-free diet(may give a false negative result) Lactose-Hydrogen Breath Test Treatment Dietary lactose restriction Lactase-treated milk (Lactaid®, DairyEase®) Lactase enzyme supplements |
|
Lactose hydrogen breath test
|
when there is a lactase deficiency, lactose is not broken down and H2 is emitted
|
|
Sucrase deficiency
|
Very rare autosomal recessive disorder
Sx: diarrhea appearing in early infancy Dx: sucrose hydrogen breath test Rx: lifelong sucrose free diet |
|
Dietary Fructose Intolerance
|
Mild dysfunction of the GLUT 5 transporter
Sx: diarrhea with ingestion of fruit and products containing high fructose corn syrup Dx: fructose hydrogen breath test Rx: dietary fructose restriction |
|
physiological requisites for fat absorption
|
Gastric Mixing (emulsification)
Bile Salts (solubilization in mixed micelles) Pancreatic Lipase (triglyceride lipolysis) Mucosal Integrity (FA uptake, packaging, export) |
|
Disruption of fat digestion and absorption can be due to
|
Gastric resection or dysmotility (gastroparesis)
Bile Salt Malabsorption or deficiency(bacterial overgrowth, TI resection, cholecystectomy) Pancreatic insufficiency: chronic pancreatitis Mucosal Diseases |
|
Maldigestion: Bacterial Overgrowth
|
Increased bacterial colonization of the small intestine (N.B. no part of the GI track is sterile)
Major Causes Hypomotility (DM, scleroderma, visceral myopathy) Achlorhydria (gastrectomy, atrophic gastritis) Jejunal diverticulosis Ileo-cecal valve resection Pathophysiology Bile salt deconjugation bile salt malabsorption decreased bile salt pool fat malabsorption Chronic mucosal inflammation |
|
Dx and Tx of bacterial Overgrowth
|
Diagnosis
Suspicion Jejunal aspiration for quantitative culture(gold standard, but not widely available) 14C-Glycocholate Breath Test Glucose-Hydrogen Breath Test* Treatment Oral systemic or non-absorbable antibiotics Usually requires chronic treatment Antibiotic rotation to prevent resistance |
|
glucose Hydrogen breath Test
|
x
|
|
Pancreatic insufficiency Causes and Pathophysiology
|
Causes
Chronic pancreatitis (common) Pancreatic cancer with duct obstruction (rare) ZE Syndrome - lipase denaturation (rare) Pathophysiology Steatorrhea occurs when the secretion of pancreatic lipase falls to < 10% of normal Disease also destroys and cells, resulting in decreased insulin and glucagon secretion Brittle diabetes appears in advanced disease |
|
Dx and Tx of Pancreatic Insufficiency
|
Diagnosis
Presumption Stimulated pancreatic secretion analysis Pancreatic imaging by CT, EUS, ERCP* Treatment Pancreatic enzyme supplements containing at least 30,000 units of lipase at each meal Enteric coated tablets PPIs, H2 blockers, or NaHCO3 keep gastric pH > 5 to prevent enzyme denaturation Reduced fat diet |
|
Global Malabsorption: Small bowel Mucosal Disease
|
Celiac disease (upper small bowel)
Crohn’s disease (terminal ileum) Whipple’s disease (duodenum, jejunum) Intestinal lymphoma Chronic giardiasis Other rare disorders: Tropical sprue Eosinophilic gastroenteritis Abetalipoproteinemia Amyloidosis Lymphangectasia |
|
Radiographic String sign
|
indicative of crohns disease
|
|
Whipples disease histology
|
foamy macrophages in lamina propria
|
|
Fecal Fat
|
x
|