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Gastric Acidity, Titratable

Item Value
Approval req'd? No
Available Stat? No
Test code GAA
Performed by Quest
Sendout? Yes
Method Titration
Patient Preparation Procedure must be scheduled in advance with the GI motility lab, 400 Parnassus, room A6102, x39383.

Contact the GI motility lab regarding instructions for ordering, patient preparation, etc.
Collection Instructions Record the volume of each sample and submit an aliquot of 10 mL (min. 6 mL) to the laboratory for titration. If the volume of a specimen is less than 6 mL, the specimen can be pooled with the specimen from the next collection interval. Do NOT pool pre- and post-stimulation specimens.
Container type Clean container or urine cup
Amount to Collect See preferred volume
Sample type Gastric fluid
Preferred volume 10 mL for each sample
Min. Volume 6 mL each sample
Processing notes Refrigerate and submit each entire sample. Order Quest # 10945X for each sample.
Units mEq/L
Normal range
Free HCl output 0.0-40.0 mEq/L


Total (titratable) acidity 10.0-60.0 mEq/L


Basal acid output (BAO) is normally < 5 mmol/h and peak output 5-40 mmol/h.
Synonyms Titratable acidity
Turn around times Test run Tuesday and Friday. Turnaround time: 2-6 days.
Additional information This test is little used today, primarily to determine whether or not an elevated gastrin level is due to achlorhydria or to monitor the adequacy of medical therapy of a gastrinoma. In the basal state the volume and acid production in each interval should be about the same. Peak acid output is computed from the output in the two highest consecutive 15 minute intervals multiplied by 2.

The acid output titratable to pH 7.0 is reported for each sample. Total acid output in each sample may be calculated by multiplying the total acidity (in mmol/L) x total sample volume (in liters).
LOINC code 14583-9
Last Updated 6/14/2011 12:06:29 PM
Entry Number 414
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