Phlebotomy Notes: Order of Draw, Tube Types, and Testing

Order of Draw and Additives

  • Importance of Order of Draw: Additives in blood collection tubes can interfere with each other, leading to inaccurate test results.

    • Example: Drawing a lavender tube (EDTA) before a green tube (Heparin) can affect heart-related test results.

  • Consequences of Incorrect Order:

    • Misdiagnosis: Incorrect order can lead to false positives (e.g., indicating a heart attack when none is occurring).
    • Inappropriate Treatment: Patients may receive unnecessary or harmful treatments based on flawed blood work.

  • Specific Tube Order Considerations:

    • Switching between paper or lavender tubes might not be critical.

    • Switching between dark green and light green tubes is significant.

    • Red and Gold tops (no additives) are less critical to switch but avoid it.

    • Nurses may be misinformed about the importance of order of draw, potentially leading to errors.

Tube Types and Additives

  • Red and Gold Tops:

    • Generally, these tubes contain no additives (but gold tops can be used for chemistry depending on the location)
    • Commonly used for "send out tests" (tests processed at a different lab).
    • Samples (serum or cells) are sent for processing.

  • Mnemonic Device:

    • "You better remember…girls love gray."
    • Yellow, Blue, Red, Green, Lavender, Gray

  • Setting-Specific Tubes:

    • Royal Blue tubes are more common in hospital or research settings.

Autoimmune Testing

  • ANA (Antinuclear Antibody) Test:

    • Used for diagnosing autoimmune diseases in patients with low immunity or suspected autoimmune disorders.
    • Drawn in gold or red tubes, depending on the facility.

Variations in Lab Practices

  • Differences Among Healthcare Providers: Policies and tubes vary.

    • University of Maryland: Uses gold instead of tiger tops.
    • LabCorp: Primarily uses Tiger Tops and Lavenders.
    • Luminous Health: Uses Lavenders and Pinks.
    • Quest: Uses Lavenders, but no Grays or Pinks.

  • Tube Interchangeability:

    • Knowing the test is more important than the tube color!
    • If a specific tube is unavailable, alternatives can be used. For example, if lavenders are unavailable but pinks are, you can use pinks for the CBC.

Light Green Tubes

  • Light Green Tops:

    • Primarily used for chemistry tests.
    • Contain Lithium Heparin (distinct from household heparin).
    • Examples of Tests: BNP, Electrolytes, Lipid Panel, CMP (Comprehensive Metabolic Panel), Troponin

  • Tube Interchangeability:

    • Tiger top tubes are interchangeable, depending on the location.

Pregnancy Tests

  • HCG (Human Chorionic Gonadotropin):

    • Pregnancy tests can be performed on blood or urine samples. HCG is tested to confirm pregnancy.