Why should you fill a light blue top tube completely?

Filling a light blue top tube completely is essential to maintain the correct blood-to-additive ratio. The light blue top tube typically contains sodium citrate as an anticoagulant, which is used for coagulation studies. For these tests to yield accurate results, the volume of blood must be precise in relation to the volume of the additive in the tube. A specific ratio, usually 9:1 (blood to anticoagulant), is required to ensure proper coagulation function assessment.

If the tube is not filled completely, there may not be enough blood to achieve this required ratio. This imbalance can lead to inaccurate test results, impacting patient care and diagnosis. Therefore, ensuring the light blue top tube is filled appropriately is critical to obtaining reliable coagulation test outcomes.