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Epic Code LAB1230278 Glucose Tolerance, 2 hour test, 75g (Gestational Diabetes)

Important Note

  • For outpatient collection: Providers please instruct patient to arrive at least 3 hours prior to the lab closing to ensure there is enough time to complete the test.
  • This test is recommended and only available for PREGNANT patients.
  • Fasting specimen required -  A fasting glucose specimen will be drawn.

Test Name Alias

Oral Glucose | GTT | OGTT 

Interface Order Alias

Currently not available

Ordering Instructions

This test is recommended as a follow-up or confirmatory test for an abnormal One Hour Post (50 gram) OGTT.

 

This test is recommended and only available for PREGNANT patients.

 

For safety and accuracy of testing, patients are encouraged to have Oral Glucose Tolerance Tests (OGTT) performed at one of our Outpatient Service Centers.

Collection Instructions

  • A fasting glucose specimen will be drawn.
  • The patient is given a 75 gram oral glucose load.
  • Another specimen is drawn 1 hour and then 2 hours later.
  • GlucoCrushTM, the glucola drink used in Spectrum Health Grand Rapids Laboratory does not contain gluten.

Specimen Collection: Blood

 

Container(s): 4.5 mL Mint Green Top (Lithium Heparin Gel) or 5.0 mL Gold Top (Serum Separator-SST Gel)

Preferred Volume to Collect: 4.5 mL

Minimum Volume to Collect: 1.0 mL

Capillary collect ok? Yes

Microtainer acceptable: Yes

 

Collection Instructions:

  • Fasting specimen required
  • Avoid hemolysis
  • After collection, gently invert tube 8-10 times.
  • Specimen should be processed within 2 hours – See Processing Instructions.

 

Processing Instructions (Laboratory, Outpatient or Off-site collection)

  • Processed Specimen: Plasma or Serum
  • Centrifuge/Spin: Yes
  • Aliquot: Yes
  • Processes Minimum Volume: 0.5 mL Plasma or Serum
  • Processing Instructions:
    • Plasma is preferred specimen type
    • Green Tube/Plasma: Centrifuge within 1 hour after collection.
    • Gold Tube/Serum: Allow blood to clot for 30 minutes in a vertical position and centrifuge within 2 hours.
    • Minimum plasma/serum volume: 0.5 mL
  • Transport Temperature: Refrigerated

Specimen Stability

Ambient: 8 hours

Refrigerate: 72 hours

Frozen: aliquot plasma/serum for longer storage

Laboratory Retention: 72 hours

Test Frequency

Available daily, usual TAT 1 day.

Reference Range

Glucose Fasting: 70-99 mg/dL

Glucose 1 Hour Post 75g: ≤180 mg/dL

Glucose 2 Hour Post 75g: 50-139 mg/dL

Performing Department

CHEMISTRY

Methodology

Enzymatic

CPT

HC GLUCOSE TOLERANCE [82951 (CPT®)]

CDM Code

80101530

Epic Test ID

1230100723;1230100113;123002002

LOINC

Currently not available

Reviewed Date

3/5/2020

Beaker Names

Beaker Procedure Name: GESTATIONAL 2 HR GTT 75G WHO
Beaker Display Name: Glucose Tolerance 75g WHO, 2 Hour (Gestational)
BEAKER TEST NAME: GLUCOSE 2 HR FOR GESTATIONAL 2 HR GTT 75G WHO
BEAKER TEST REPORT NAME: Glucose 2 Hr for Gestational 2 Hr GTT 75g WHO

Beaker Location, Container and Temperature

BW CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

BL CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

BR CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

GM CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

KL CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

KL CHEMISTRY:  GOLD TOP SST TUBE R (Acceptable) – Refrigerated

LH CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

PH CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

 RC CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

UN CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated

UN CHEMISTRY: GOLD TOP SST TUBE R (Acceptable) – Refrigerated

ZH CHEMISTRY: GREEN LI HEPARIN PST TUBE R (Preferred) – Refrigerated