- Confirm suspected Z-E syndrome.
- Demonstrate achlorhydria (absence of hydrochloric acid in the gastric juice produced in the stomach).
- Estimate or show parietal cell mass.
- Patients should not eat for 10 to 12 hours before the analysis (usually the night before the day of the analysis).
- Patients shouldn’t take any medication, especially anticholinergic agents, H2 blockers, antacids, since the night before as they can alter the results.
- Patients should be weighed before the procedure.
- The health worker should explain the procedure to the patient in simple words, to enable him/her to prepare his/her mind for the analysis as well.
- A radio-opaque stomach tube (16 French sizes).
- 50ml plastic or glass syringe.
- 1ml tuberculin syringe.
- Emesis basin.
- 100ml graduated cylinder.
- Adhesive tape.
- Indicator solution, such as phenol red.
- Unit nurse.
- Medical technologist.
- Patients should remove all dentures.
- The technologist should lubricate the nasogastric tube.
- The technologist examines the nostrils of the patient and chooses the one (while the patient is still sitting upright with neck flexed) through which breathing is easier and the nostril is wider.
- He gently pushes the radio-opaque stomach tube through the patient’s nostril (intubation). Sometimes the tube may get curled up in the pharynx, causing excessive coughing or gagging. This prevents further passage; at this time, the tube is drawn back some few inches before continuing with the intubation.
- During the insertion, reassure the patient, instruct him/her to swallow, and continue to swallow throughout the intubation period. After the tube has progressed to about 40cm (the first mark on the tube), the patient may be allowed to keep his head comfortably.
- Continue intubation gently until the fourth mark (65cm) is reached.
- The technologist tapes the tube to the patient’s nose with adhesive tape.
- The technologist sends the patient to an x-ray for fluoroscopy to check the position of the tube. The tube should lie along the lesser curvature with its tip in the atrium of the stomach.
- Empty the stomach contents with a 50ml syringe; continue until the gastric juice is finished.
- Record the pH, volume, and color. You may discard this residual volume. (If the residual volume is more than 100ml or food particles are present, the possibility of outlet obstruction should be considered.)
- After emptying the stomach of the residual volume, begin a collection of gastric juice under basal conditions. At least four samples should be collected each fifteen minutes apart in separate containers.
- Spot-check the gastric fluid specimen to know whether the patient is making acid or is not (achlorhydria).
- After collecting gastric juice under basal conditions, augmented or stimulated gastric analysis may be carried out as follows:
- After the intramuscular stimulants, resume gastric acid collection again 15 minutes apart, a total of 4 to 8 collections (with pentagastrin peak response is 30 to 90 minutes). The samples are collected and marked 1, 2, 3, 4, 5, 6, 7, 8, in separate containers.
- After the basal and stimulated gastric juice collection, the specimen are forwarded to the laboratory for evaluation of the following values:
- Basal acid output (BAO).
- Maximum acid output (MAO). This is the sum of the four highest consecutive 15 minutes samples after stimulation.
- Peak acid output (PAO). This is the sum of the two highest consecutive 15-minute samples multiplied by 2.
- Basal acid output and maximum acid output ratio as a percentage (BAO/MAO × 100).
- Esophageal perforation.
- Decreased mean p0₂ (a measure of blood oxygen levels).
- Fasting volume; 20-100ml.
- Fasting pH; ˂2.0ml.
- BAO for men; 0-5mmol/hour.
- BAO for women; 0-4mmol/hour.
- MAO for men; 5-26mmol/hour.
- MAO for women; 7-15mmol/hour.
RISKS OF GASTRIC FLUID ANALYSIS
Both the basic acid output test and the gastric acid stimulation test require gastric intubation through the mouth or nose. None of these tests is recommended for patients suffering from esophageal problems, severe gastric hemorrhage, aortic aneurysm, or congestive heart failure.
Patients sensitive to pentagastrin may not be recommended for gastric acid output tests. Intubation following patient fasting overnight (12 hours) poses a risk of injury to the esophageal wall. The stress of intubation for hours coupled with ejection of saliva to avoid diluting the stomach contents is likely to initiate or increase emotional as well as psychological stress on the patient.
- What is the gastric function test?
Test of gastric function is of value for many aspects in the development of drugs and their delivery systems.
Intragastric and oesophageal pH meter and analysis of gastric juice can be used to assess therapy of disorder associated with either increased acid output or gastroesophageal reflux disease.
- What is the color of gastric juice?
In tier normal state, gastric juices are usually clear in color. HCL is an important component in gastric juice. It is a strong acid produced by the parietal cells in the corpus pepsin and absorption of nutrients
- What is the pH value of the stomach?
The normal volume of stomach fluid is 20 to 100 ml and the pH is acidic (1.5 to 1.5 to 3.5).
- What is the function of gastric juice?
Gastric juice is a combination of hydrochloric acid (HCL), lipase, and pepsin. Its main function is to inactivate swallowed microorganisms, thereby inhibiting infectious agents from reaching the intestine.
- What happens if the stomach pH is too high?
Having a high level of stomach acid can increase your risk of developing another stomach-related health condition. This includes a Peptic ulcer. Peptic ulcers are sore that can develop when gastric acid begins to eat away the lining of your stomach.