NHA Phlebotomy Certification Practice Exam

What is the appropriate method to draw blood from a patient who states she is a difficult draw and requests a skin puncture for a PTT test?

1. Use a butterfly needle and transfer to a red tube

2. Use a syringe and transfer to a light blue tube

3. Use a vacutainer with a large bore needle

4. Use a capillary tube and transfer to a green tube

The correct answer is: Use a syringe and transfer to a light blue tube

Choosing the method of using a syringe for blood collection is appropriate in this scenario because it allows for better control and reduces the risk of vein collapse, especially for patients who are considered difficult draws. When a patient indicates that they are a difficult draw, a syringe can be particularly advantageous as it creates a vacuum that can be adjusted, allowing for a gentler approach to collecting blood. In the case of testing for prothrombin time (PTT), it is crucial to use the correct tube for collection. The light blue tube, which is used for coagulation studies, contains sodium citrate as an additive, which helps preserve the plasma and is essential for accurate testing. The use of a capillary tube to collect blood via skin puncture is also a viable option, but the requirement for a PTT test specifies that traditional venous blood collection would typically yield the most accurate and reliable results, making the syringe method preferred in this context. Overall, the combination of the syringe method for a difficult draw and its suitability to be combined with a light blue tube for the PTT test ensures that you are providing an effective and reliable blood draw for the patient.