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Xylose Absorption Test, Adult (5g dose)

Mnemonic:    [UNLIST LAB]
Name:    Xylose Absorption Test, Adult (5g dose)
Specimen:     These instructions are valid only for ADULT sample collections.

Patient Prep: Patient should fast for 8 hours (Min: 4 hours) prior to administration of xylose.

Collect: Fasting serum, five-hour urine, and two-hour serum according to the following instructions.

Specimen Preparation:
1. Just prior xylose administration, patient should empty his or her bladder (DO NOT collect this urine).

2. Just prior to xylose administration, collect first serum specimen (Min: 0.5 mL). Allow serum to clot completely at room temperature. Separate serum from cells ASAP or within 2 hours of collection. Label this specimen as "FASTING SERUM" and prepare for transport.

3. Give adults 5 g D-xylose in 250 mL water. Encourage the patient to drink an additional 250 mL water following the xylose dose. The patient may have water as desired, but no other food or fluids. Smoking should be prohibited. The patient should rest in a chair or on a bed until completion of test. Mild diarrhea is common following xylose ingestion.

4. Immediately following the xylose dose, collect all urine for the next five hours. Measure and record the volume, mix well, and remove a 5 mL aliquot (Min: 3 mL) and prepare for transport. Label this specimen as "FIVE-HOUR URINE." Record the total volume and the xylose dose given on the urine aliquot tube.

5. Two hours after administration of xylose dose, collect the second serum specimen (Min: 0.5 mL). Allow serum to clot completely at room temperature. Separate serum from cells ASAP or within 2 hours of collection. Label this specimen as "TWO-HOUR SERUM" and prepare for transport.

6. Record the xylose dose given and the total volume of the five-hour urine on the test request form.

Failure to include all required information will result in delay of turnaround time.

For children, refer to Xylose Absorption Test (Child) (ARUP test code 0020612).
Transport Temp:    Refrigerated
Ref Lab/Code:    ARUP 0020609
  Method:    Spectrophotometry
Note:    .