010715 stomach disorders 3

Question 1

causes of elevated acid secretion

Answer 1

most important cause: elevated gastrin

elevated vagal tone
elevated histamine
elevated parietal cell mass
paraneoplastic (non-gastrin-rare)

Question 2

elevated gastrin values cannot be interpreted without

Answer 2

knowledge of pH

normally, gastrin increases due to reduced delivery of acid to antrum

Question 3

Zollinger-Ellison syndrome

Answer 3

hypersecretion of gastric acid due to gastrin secreting neuroendocrine tumor

isolated gastrinoma (75%)
as component of multiple endocrine neoplasia I (25%)

Question 4

what is diagnostic of Zollinger Ellison syndrome

Answer 4

over 1000 pg/ml of gastrin with low pH

Question 5

in what does secretin stimulation result in gastrin increasing?

Answer 5

Zollinger Ellison

Question 6

types of Zollinger Ellison syndrome

Answer 6

sporadic or MEN1

Question 7

sporadic Zollinger Ellison

Answer 7

single gastrinoma typically in duodenum or pancreas

Question 8

clinical manifestations of Zollinger Ellison

Answer 8

more severe ulcer disease (extends to distal duodenum and jejunum)

diarrhea

Question 9

causes of gastrin mediated high acid secretion

Answer 9

Zollinger Ellison
H pylori (via reduced somatostatin)

antral G cell hyperplasia
gastric outlet obstruction
retained antrum (antrum is no longer in the path of acid leaving the stomach due to some disconnect-in gastric surgery--so the antrum gets high pH stuff and keeps producing acid b/c it fails to sense properly)
short bowel syndrome
renal failure (rare)

Question 10

secretin provocative test is used for

Answer 10

diagnosing Zollinger Ellison gastrinoma

Question 11

acute H pylori infection has what effect on acid secretion?

Answer 11

decreases acid secretion

Question 12

consequences of low acid secretion

Answer 12

overall well tolerated with modern diet. impaired protein digestion

impaired absorption of Fe, Ca, B12
gastric bacterial overgrowth
small bowel bacterial overgrowth
impaired delivery of certain drugs

Question 13

Schilling test of vitamin B12 deficiency

Answer 13

replace vit B12 parenterally
24 hr urine collection of radiolabelled Vit B12 orally

if low, repeat while giving IF
if still low repeat after empiric antibiotic tx for sm bowel bac overgrowth

if still low–points to pancreatic insufficiency or terminal ileal disease

Question 14

conditions affecting acid secretion also affect

Answer 14

IF secretion
pepsin/lipase secretion

bicarbonate/mucous secretion

Question 15

peptic ulcer

Answer 15

ulcer in stomach or duodenum

Question 16

melena

Answer 16

black feces due to upper GI bleeding

Question 17

biopsy of stomach can look for (in the context of ulcers)

Answer 17

H pylori