Gastric analysis

Gastric Analysis

Indication for performing gastric analysis:

1- To determine whether the pt can secrete or not any gastric acid .

2- To measure the amount of acid produced in pt with symptoms of peptic ulcer .

3- To reveal the hypersecretory state characteristic of Zollinger-Ellison syndrome .

4- To determine the completeness of vagotomy by the insulin test .

Three measurements to be performed on each sample of gastric secretion :

1- Volume in milliliters .

2- The ph measured electrometrically .

3- Titratable acidity expressed in meq/l

The gastric secretion titrated to the end point with 0.1 N NaOH . end point can be determined by using indicator such as phenol red .

** Basal Secretion : is the total amount of acid secreted per one hour ( usually four samples are taken in 15 min. interval ).

** Maximal acid output = Maximal histamine test : the amount of acid secreted in one hour after injection of histamine .

** The peak acid output :is the greatest acid output in any two successive 15- min. period in the augmented histamine test .

Macroscopic physical examination:

1-The normal gastric secretion is pale gray , translucent , slightly viscus &bad odor .

2- Normal volume up to 50 ml.

3- The presence of bile is normal ( color yellow to green ) but if it is in greater amount it will indicate pyloric obstruction .

4- Following 12- hours fasting the presence of food particles is abnormal indicating delayed gastric emptying .

5- Mucus is normal but if present in greater amount may be due to swallowed saliva or nasorespiratory secretion or due to reflux of duodenal content due to obstruction of small intestine .

6- Blood streaks is normal due to intubation , but if it is brown & granular may be due to gastric lesions such as gastritis or ulcer or carcinoma or may be swallowed from mouth ,nasopharynx or lungs .

7- PH should be measured electrometrically .

Microscopic examination

*is to look in the sediment for epithelial cells , starch granules ,yeasts , bacteria, fat droplets , bits of tissue , leukocytes , RBCs , food reminents .

· Yeast & the Bous-oppler bacillus may occur in large numbers if retention of gastric contents is present .

· Aspiration of gastric contents for mycobacterial culture is indicated in pt who are suspected of having pulmonary tuberculosis who are unable to produce adequate sputum samples .

· The major usefulness of serum gastrin assay is for the diagnosis of the Zollinger –Ellison syndrome in which tumors of the pancreas secrete excessive amount of gastrin causing severe peptic ulcer disease

بقلم

عادل عبدالحليم السلايمه

أخصائي طب مخبري

مسؤول جودة المياه /بلدية الخليل