Glucose

Casandra

Casandra Test Code LC45073Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 001032CPT Code 82947

Also known as: Blood Sugar

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, as defined by the ADA as no caloric intake for at least eight hours. Glucose stability is maintained for 14 days at room temperature in separated, nonhemolyzed, sterile serum without fluoride. Use sodium fluoride or lithium iodacetate to inhibit glycolysis if the sample cannot be processed quickly.

Limitations

Glucose concentrations decrease ex vivo due to glycolysis, which can vary based on glucose concentration, temperature, and white blood cell count. Sodium fluoride can maintain glucose stability long-term, but its in-use decrease rate is parallel with other tubes for the first hour post-collection. Leukocytosis can enhance glycolysis even with fluoride present. Glycolysis rates are estimated to decrease glucose by 5-7% per hour.

Test Details

Methodology

Automated Analyzer (Clinical Chemistry)

Biomarkers

LOINC Codes

Order Codes

2345-7

Result Codes

2345-7

Result Turnaround Time

1 day

Specimen

Serum

Volume

1 mL

Minimum Volume

0.7 mL

Container

Red-top tube, gel-barrier tube

Collection Instructions

Separate serum or plasma from cells within 45 minutes of collection. Label specimen as serum or lithium heparin plasma.

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.