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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Glucose, Fasting

Test Code(s): FSGLU / HCFSGLU

CPT Code(s): 82947

Methodology: Hexokinase

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.


Specimen Requirements

Specimen: Blood

Patient Preparation: Patient should have nothing to eat or drink (except water) for 8-10 hours before test.

Collection Container: Preferred: Green cap with yellow ring (PST)
Also Acceptable: Green top, Red cap with yellow ring (SST), Red top

Collection Volume: Preferred: 1 mL
Pediatrics: 0.4 mL

Sample Analyzed: Plasma or serum

Volume Required: Preferred: 0.5 mL
Pediatrics: 0.2 mL

Specimen Processing: Centrifuge.  If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial.  Refrigerate.

Specimen Transport: Transport specimen to the laboratory.  Transport with coolant pack if coming from outreach location.

Stability: Ambient: 8 hours
Refrigerated: PST - 48 hours; if off cells or SST - 4 days
Frozen: okay


Interpretation

Reference Interval:
 Age  mg/dL
 0 days to 23 hours  40-60
24 hours to 30 days  50-80
31 days to 5 years  60-99
6 years and up  70-99

Critical Calls: View

Additional Information:

A fasting glucose greater than or equal to 100 mg/dL, but less than 126 mg/dL, indicates an impaired fasting glucose level and a relatively high risk of developing diabetes.

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