Gastric function tests and interpretation for clinical practice

1. Dr. S.Sethupathy

2.  After overnight, 20-50- ml
 More than 100-120 ml – abnormal volume
 Causes: hypersecretion of acid
 Retention due to pyloric obstruction
 Regurgitation from duodenum
 Consistency- fluid No food particles
 Clear
 Red/dark red/ brown- ulcer ,bleeding
 Coffee ground – ca.stomach

3.  Bile- reflux gastritis
 Mucus- carcinoma stomach
 Free acid- 0-30 mmol/L
 More than 50 mmol/L – hyperacidity
 Total acid – 10- 40 mmol/L
 Organic acids- achlorhydria , hypochlorhydria

4.  Cancer stomach
 Perinicious anaemia
 Advanced gastritis
 No acid – to investigate

5.  Two pieces of toast and tea or oat meal
porridge
 Residual content removed before meal
 Gastric juice collected at intervals
 Free acid more than 50 mmol/L –
duodenal,gastric ulcer, Zollinger Ellison
syndrome, Pyloric stenosis, ch.cholecystitis

6.  7% ethanol stimulation 100 ml
 Overnight fast , residual contents removed
 Sample every 15 mins
 Total and free acidity
 Easy to administer than oat meal
 Rapid and gastric emptying is better
 Unphysiological and free acid is more
 Caffeine S.Test -500mg in 200 ml - similar
to alcohol stimulation

7.  Pentragastrin is a pentapeptide having the
same terminal sequence of four amino acids
- as gastrin
 It is butyl oxy carbonyl-beta alanine-Trp-
Met-Asp-Phe-CONH2
 BAO, MAO, PAO are increased in Zollinger
Ellison syndrome.
 In atrophic gastritis, pernicious anemia and
gastric carcinoma, there is achlorhydria.

8.  Histamine is a potent stimulus of gastric
secretion
 test is done by giving 0.04 mg/kg histamine
s.c.
 Histamine fast achlorhydria is due to
pernicious anemia.
 Hypotension.
 Antihistamine to block H1 receptor effects of
histamine.
 Cimetidine, a H2 histamine receptor blocker
is used in peptic ulcer.

9.  Histamine analog – Histalog
 3-beta amino ethyl pyrazole
 10-50- mg
 No side effects

10.  Insulin stimulates HCl secretion
 Duodenal ulcer
 Hypoglycemia
 15 units soluble iv

11.  Basal acid output (BAO) is less than 10
mmol/hour in males and less than 5.5
mmol/hour in females.
 It is increased (more than 15 mmol/hour) in
Zollinger Ellison syndrome.
 Maximal acid output (MAO) is 7-45
mmol/hour and is after stimulation.
 Peak acid output (PAO) after stimulation is
12-60 mmol/hour.

13.  It is increased in gastrinoma, Zollinger
Ellison syndrome.
 Moderate elevation of gastrin is also seen in
pernicious anemia, hyper secretion of gastrin
by antral G cells and renal failure, proton
pump inhibitors intake.
 After secretin , serum gastrin level increases
in ZES but not in other conditions.

14.  Condition serum gastrin (pg/ml)
 Normal < 500
 Antral gastritis low to normal
 Duodenal ulcer 300 - 500
 Fundal gastritis 300 - 60,000
 Z.E. syndrome3,500 - 60,000

15.  Pancreatic gastrin producing cells(Common)
 Gastric gastrin producing cells
 Peptic ulcer, diarrhea, steatorrhea
 Fasting serum gastrin- >1000pg/mL
 Secretin test- 2,5,10,15,20 mins –difference
> 200pg/mL

16.  Gastric secretion is stimulated and after one
hour, a dye bound to resin (Azure-A) is given
orally.
 Based on the surrounding pH, the resin
releases the dye
 It is absorbed and excreted in urine.
 The quantity of dye in urine indicates the
acidity of gastric juice. It rules out
achlorhydria.
 It is used as a screening test.

17.  H.pylori infection is playing a role in acid
peptic disease.
 Urease enzyme
 The presence of urease- pyloric infection.
 Urea breath test
 13 C, 14 C- urea
 Breath CO2
 Serological tests – less reliable

18.  Vitamin B12 deficiency is macrocytic anemia and
c megaloblastic
 Low serum vitamin B12 concentrations
 Pernicious anemia –intrinsic factor deficiency or
to intestinal malabsorption or dietary deficiency.
 The test involves - two orally administered test
doses of radioactive labelled vitamin B12
 Measuring radioactivity in a urine specimen
collected for five hours.
 The first test dose -alone
 The 2nd test dose - three days later) - with
intrinsic factor.

19. Condition
Results
1st Stage 2nd Stage
normal absorption absorption
dietary
deficiency
absorption absorption
intestinal
disease
malabsorption malabsorption
pernicious
anemia
malabsorption absorption

20.  Limited but specific uses in certain conditions
 Perinicious anaemia
 ZES
 Peptic ulcer
 Now endoscopy plays a major role
 Biopsy can be taken

21. Thank YOU