A mint green top tube (or preferably a dark green top tube with a short 4.0mL draw) containing lithium heparin is used for arterial blood gas (ABG) samples. However, it's crucial to note that evacuated lithium heparin tubes used for plasma collection are not suitable for ABG analysis.
Understanding ABG and Tube Selection
Arterial blood gas (ABG) testing measures the levels of oxygen and carbon dioxide in the blood, providing vital information about lung function and overall respiratory health. The choice of blood collection tube is critical to ensure the accuracy of the results. Heparin, an anticoagulant, is necessary to prevent blood clotting, which would interfere with the analysis. Lithium heparin is preferred over sodium heparin for ABG testing, although the use of sodium heparin is still mentioned as acceptable in some resources.
- Mint Green/Dark Green: These tubes indicate the presence of lithium heparin. The preference for the dark green, shorter tube is likely due to minimizing the interference of the additive in smaller samples.
- Importance of the Anticoagulant: Heparin prevents clotting, preserving the blood sample's integrity for accurate analysis. Using the incorrect tube, such as one containing a different anticoagulant or no anticoagulant at all, will lead to inaccurate results.
- Evacuated Tubes: While evacuated tubes are commonly used, the specific type must be appropriate; those designed for plasma collection may not be suitable for ABG testing.
The information above is synthesized from various sources including: Bassett Healthcare Network Clinical Laboratories guidelines (July 12, 2023), which specifically mention the use of mint green or dark green lithium heparin tubes for ABG samples.
