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Test Code LAB13324 Glucose Tolerance, 4 Hour - Adult Inpatient

Department

Chemistry

Collection Requirements

This test is designed for when the physician specifies additional glucose levels beyond the standard 2 hour.

8 hour fast is required

Patient should be on a high carbohydrate diet for 72 hours prior to the test.

Draw the fasting glucose as soon as possible after patient’s arrival.

Give 75 grams of prepared dextrose and then draw a glucose specimen at one hour intervals for up to 6 hours (as specified by the physician).

Verify each collection for the exact draw time. Do not accept default draw times.

Primary Collection Container

Green PST (Lithium Heparin)

Alternate Collection Container

Green Microtainer PST

Transport

Plasma refrigerated

Preferred Transport Temperature

Refrigerated

Processing

Centrifuge and refrigerate.

Separate from cells if testing is delayed more than 2 hours. Deliver to Chemistry ASAP.

Stability

Refrigerated: 72 hours

Minimum Testing Volume

0.5 mL

Reference Range

By report

Methodology

Hexokinase (HK) Roche c503

Performed

Sunday – Saturday

Reported

As completed

Unacceptable Conditions

Gross hemolysis.

Delay in separating cells from plasma.

Additional Information

Test includes: Fasting glucose, up to 6 timed, post challenge glucoses and an interpretation guideline for the diagnosis of Diabetes Mellitus.