Glucose, Plasma

Casandra

Casandra Test Code LC67131Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 001818CPT Code 82947

Also known as: Blood Sugar, Fasting Blood Sugar, Random Blood Glucose

Clinical Use

Order Test

Use

Diagnose diabetes mellitus; evaluate disorders of carbohydrate metabolism including alcoholism; evaluate acidosis and ketoacidosis; evaluate dehydration, coma, hypoglycemia of insulinoma and neuroglycopenia

Special Instructions

Blood should be drawn in the morning after an overnight fast, defined by no caloric intake for at least eight hours. The specimen should be labeled as plasma and mixed well. Plasma should be separated within 45 minutes of collection. Gray-top tubes may be submitted without centrifugation.

Limitations

Glucose concentrations can decrease ex vivo due to glycolysis, which varies with factors like glucose concentration, temperature, white blood cell count, and other factors. Glycolysis can be mitigated using inhibitors like sodium fluoride or lithium iodacetate. In whole blood, glucose is stable for up to 72 hours in the presence of fluoride. In separated, nonhemolyzed, sterile serum without fluoride, the glucose concentration remains stable for 14 days at both room temperature and refrigerated conditions. However, leukocytosis may still increase glycolysis despite fluoride presence.

Test Details

Methodology

Automated Analyzer (Clinical Chemistry)

Biomarkers

Glucose

Analyte

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Order Codes

1558-6

Result Codes

1558-6

Result Turnaround Time

1 day

Specimen

Plasma

Volume

Entire collection

Minimum Volume

0.5 mL

Container

Gray-top (sodium fluoride) tube or green-top (lithium heparin) tube

Collection Instructions

Separate plasma within 45 minutes of collection. Only gray-top tubes may be submitted without centrifugation. Label specimen as plasma. Mix well.

Patient Preparation

Blood should be drawn in the morning after an overnight fast. Per the American Diabetes Association (ADA), fasting is defined as no caloric intake for at least eight hours.