NHA Phlebotomy Certification Practice Exam

Failing to adequately invert a lavender stopper tube after collection will:

1. Cause hemolysis.

2. Falsely elevate calcium results.

3. Destroy coagulation factors.

4. Produce a clotted specimen.

The correct answer is: Produce a clotted specimen.

Inverting a lavender stopper tube, which is commonly used for hematology tests like complete blood counts, is crucial for ensuring that the anticoagulant inside the tube is mixed thoroughly with the blood specimen. Failing to adequately invert the tube can lead to the formation of clots within the specimen. When blood is drawn into a tube with an anticoagulant, the anticoagulant is meant to prevent clotting by binding calcium and inhibiting the clotting cascade. Inadequate mixing means that the anticoagulant will not be evenly distributed throughout the blood, allowing clot formation to occur. When a specimen is clotted, it can interfere with test results, particularly in tests that require a liquid sample. This can lead to the need for a repeat draw, which is not ideal for patient care or laboratory efficiency. Proper technique in handling and processing specimens is essential in phlebotomy to ensure accurate test results and patient safety.