GI

Question 1

GERD

Answer 1

-most common disorder in esophagus
-endoscopy with biopsy for dysphagia
-H2RA/PPI/AA

Question 2

H. Pylori Diagnostics / TX

Answer 2

1. Biopsy (culture, urease enzyme activity detection)
2. C-breath test
3. Immunoassay for IgG antibody (may remain positive for years even after successful treatment)

PPI with 2: amoxi, clari, metro, or MTPB

Question 3

All major phases of absorption may simultaneously be affected, i.e. fats, proteins, carbohydrates, vitamins, minerals, etc. This syndrome called general malabsorption is characterized by

Answer 3

amylorrhea (excess starch), steatorrhea (excess fat), and creatorrhea (meat fibers, protein)

Question 3

General Malabsorption/Maldigestion May Be Due To:

Answer 3

1. Pancreatic disease
2. Zollinger-Ellison syndrome
3. Liver disease
4. Intestinal disease (CD/CD)
5. Resin tx

PIZLR

Question 4

Tests of nonspecific biochemical abnormalities seen in malabsorption

Answer 4

1. Low Ca < 8.5
2. High alk phos > 129
3. Low urea nitrogen < 6
4. Hypocholesterolemia (normal chol is < 200)
5. Prolonged prothrombin time
6. Flat glucose tolerance curve

CCAPN

Question 4

Specific malabsorption/maldigestion defects

Answer 4

1. Disaccharidase deficiencies:
   -lactase deficiency
   -sucrase deficiency
   -maltase deficiency
2. Glucose-galactose malabsorption
3. Pernicious anemia
4. Protein-losing enteropathy
5. Blind-loop syndrome
6. Jejunal diverticulum
7. Parasitic infestations

JP is a BD so he goes to GAP

Question 5

Carbohydrate malabsorption

Answer 5

-D-xylose absorption test (decreased)
-Disaccharidase test (decreased)
-Breath hydrogen test (increased)

Question 6

Fat malabsorption

Answer 6

-Fecal fat determination (elevated)
-14C-triolein breath test (decreased)

Question 7

Bacterial overgrowth

Answer 7

14C-Xylose breath test (increased)

Question 8

Other tests in malabsorption/digestion:
Schilling test will be ___
Sweat test will be ___

Answer 8

1. Decreased
2. Increased in cystic fibrosis

Question 9

Celiac Disease

Answer 9

1. Gluten in the patient’s diet at the time of testing for IgA endomysial ab (EMA) against transglutaminase
2. Positive = bowel biopsies
3. Diagnosis confirmed with resolution of sx after cutting out gluten

*in celiac disease but IgA deficient = need total IgA quantitation and IgG antibodies to tissue transglutaminase testing

Question 10

ABSORPTION OF VITAMIN B12 AND PERNICIOUS ANEMIA

Answer 10

-Suspicion of pernicious anemia (macrocytic anemia) can be confirmed by measuring autoantibodies against intrinsic factor
-Diagnosis can also be confirmed by parenteral administration of B12 with resolution of sx

Question 11

Schilling Test for Vitamin B12

Answer 11

-orally administering 57Co-radiolabeled B12 and quantitating its appearance in urine

-reference population excretes > 8% of the ingested dose in a 24 hour urine collection while < 7% is excreted in pernicious anemia

-if abnormality corrects with the co- administration of intrinsic factor with B12, the defect is due to deficiency of intrinsic factor rather than malabsorption due to pancreatic or ileal causes

Question 12

SWEAT TEST FOR THE DIAGNOSIS OF CYSTIC FIBROSIS

Answer 12

-In cystic fibrosis, sweat chloride values are 60-120 mmol/L; normal values are < 60 mmol

-Only acceptable test is the sweat test done by iontophoresis with direct determination of chloride or sodium

*Normal Cl < 60, Na 10-90
*Elevated in CF: Cl 60-120, Na 60-180 (overlap = less useful)

Question 13

Black, tarry stools

Answer 13

-Drugs (such as salicylates, steroids, reserpine, indomethacin, colchicine, iron, CRISSI) often cause increased gastrointestinal blood loss, resulting in positive occult blood tests

-False neg: ascorbic acid (NA)

-False pos: horseradish (peroxidase) (PH)

Question 14

IDA LABS

Answer 14

• ↓ MCV (norm is 82-98), ↓ MCH, ↓ MCHC
• ↓ Serum iron
• ↓ Serum ferritin
• ↑ TIBC (norm 250-450)**
• ↓ Transferrin saturation index

everything LOW, except high TIBC

mainly due to blood loss

Question 15

Vitamin B12 Deficiency Labs

Answer 15

• ↓ Serum B12 levels (< 100) (Norm: 211)
• ↓ Reticulocyte count
• ↑ MCV (normal is 82-98), 100+
• ↑ methylmalonic acid (0.4+) & homocysteine levels

homo: norm is <15 so 15+ is high

+ has neuropsychological sx

Question 16

Folic Acid Deficiency Labs

Answer 16

• ↓ Serum folate (< 3.1)
• ↓ Reticulocyte count
• ↑ MCV (norm is 82-98)
• ↑ serum homocysteine levels only (15+)

difference for B12: folate down instead of B12 and ONLY homo up

Question 17

Anemia of Chronic Disease Labs

Answer 17

• ↓ Hgb < 10
• ↓ Serum iron (hypoferremia)
• Normal or ↑ serum ferritin
• ↓ TIBC (difference) < 250

Normal iron stores, defect is release