gastric acid secretion

Indications

• Zollinger-Ellison syndrome
• retained antrum syndrome
• G-cell hyperplasia
• vagal hyperfunction

Contraindications

contraindications for gastric intubation

• esophageal varices
• diverticula
• esophageal stenosis
• malignant neoplasm of the esophagus
• aortic aneurysm
• severe gastric hemorrhage
• congestive heart failure

Reference interval

• normal pH of stomach is 1-2
• basal secretion
  • male: 0-10 meq HCl/hour
  • female: 0-6 meq HCl/hour
• peak secretion (after pentagastrin stimulation)
  • male: 12-60 meq HCl/hour
  • female: 8-40 meq HCl/hour
  • peak response in 15-45 min SC; 10-30 min IM

Clinical significance

• basal gastric output (BAO) follows a circadian pattern
• it is highest from 1400-2300 hours
• peak gastric output (PAO) may be as high as 60 meq/hour in some normal individuals
• values > 60 meq/hour (> twice BAO) are suggestive of Zollinger-Ellison syndrome
• BAO/PAO values of > 0.6 are common in patients with Zollinger-Ellison syndrome

Increases

(increased BAO)

• peptic ulcer (5-15 meq/hour)
• Zollinger-Ellison syndrome (> 20 meq/hour
  • values as high as 60 meq/hour) are common
• retained antrum syndrome
• G-cell hyperplasia
• vagal hyperfunction
• systemic mastocytosis
• basophilic leukemia

Decreases

(decreased gastric acid output)

• pernicious anemia (no gastric acid output)
• gastric ulcer (some)
• carcinoma of the stomach
• chronic gastritis
• gastric polyps
• myxedema
• vagotomy
• antrectomy

Procedure

• pass Levin tube
• confirm position by X-ray or fluoroscopy
• basal output: collect 2 15 minute specimens or a 12 hour nocturnal* collection
• pentagastrin 6 ug/kg SC or IM
• peak output: collect 6 15 minute specimens after stimulation
• specimens are collected with the patient in an uright position

* for nocturnal collection, patient must remain in uright position & gastric acid must be aspirated continuously

More general terms

• special chemistry test

More specific terms

• gastric acid free secretion

Additional terms

• gastric acid (stomach acid)
• gastric fluid
• gastrin in serum
• peptic ulcer disease (PUD)
• Zollinger-Ellison (ZE) syndrome (gastrinoma)