Test Code GTT3P Glucose, 3-Hour Tolerance, Pregnant Females, Plasma or Serum
Methodology
Hexokinase-Glucose-6-Phosphate Dehydrogenase
Performing Laboratory
Aspen Valley Hospital
Physician Office Specimen Requirements
Call Aspen Valley Hospital Laboratory at 970-544-1570 to
obtain glucose tolerance beverage and for procedure for calculating
proper dosage of beverage.
Patient Preparation
Patient should be fasting for 12 hours prior to test. A fasting urine specimen is also required and should be collected before patient drinks the glucose tolerance beverage. Timing for blood draw starts when patient finishes drinking the glucose tolerance beverage.
Specimen Collection
Plasma or serum and urine are required for this test.
Submit only 1 of the following specimens:
Plasma
Container/Tube: Light green-top (lithium heparin gel) tube(s)
Specimen: 2 mL (minimum
volume: 0.5 mL) of lithium heparin plasma
Transport Temperature: Refrigerate
Collection Instructions: Fasting (12
hour). After fasting specimen is drawn, instruct patient to
drink glucose tolerance beverage. A plasma specimen is drawn for
each specimen: 1 hour, 2 hours, and 3 hours after ingestion
of glucose tolerance beverage. Spin down immediately and send
entire tube to laboratory.
Note: 1. Indicate corresponding draw time
and as plasma on request form.
2. Label specimen appropriately (corresponding draw time and as
plasma).
Serum
Container/Tube: Gold-top serum gel tube(s)
or Plain, red-top tube is also acceptable.
Specimen: 2 mL (minimum
volume: 0.5 mL) of serum
Transport Temperature: Refrigerate
Collection Instructions: Fasting (12 hour). After fasting specimen is drawn, instruct patient to drink glucose tolerance beverage. A serum specimen is drawn for each specimen: 1 hour, 2 hours, and 3 hours after ingestion of glucose tolerance beverage. Allow specimen to clot for approximately 10 minutes and spin down. If drawing gold-top serum gel tube, send entire tube to laboratory. If drawing plain, red-top tube, remove serum and place in separate plastic vial.
Note: 1. Indicate corresponding draw time
and as serum on request form.
2. Label specimen appropriately (corresponding draw time and as
serum).
Urine
10 mL (minimum volume: 1 mL) from a fasting, random urine collection in a plastic urine container. No preservative. Send specimen refrigerated.
Note: 1. Indicate urine on request form.
2. Label specimen appropriately (urine).
Reference Values
Fasting glucose: <96 mg/dL
1-Hour glucose: <181 mg/dL
2-Hour glucose: <156 mg/dL
3-Hour glucose: <141 mg/dL
Critical values (automatic call-back): <50 mg/mL or >500 mg/dL
Fasting urine glucose: negative
Note: Reference ranges are for fasting glucose.
Day(s) Test Set Up
Monday through Sunday
Test Classification and CPT Coding
82951 - glucose tolerance test, 3 specimens
82952 x 2 - glucose tolerance test, each additional