A phlebotomist is collecting sample for a complete blood count (CBC) and a prothrombin time (PT) from an adult patient. Both were collected into the proper tube for the test. It was a difficult draw, completed without incident using a butterfly (because the patient's veins were hard to feel) and a syringe. After the collection was complete, and while mixing the tubes three times by inversion, the phlebotomist noticed that the sample volume in the tube for the PT was a little low. To save time, he or she added a little sample from the CBC tube to the PT tube. This action will result in which of the following outcomes?

Question

Quizplus · Accepted Answer

Adding extra sample from one tube to another can dilute the anticoagulant in the PT tube, which can cause clotting time to decrease and result in an incorrect result. Therefore, the PT test will be affected, and re-collection of a proper sample for the PT test will be necessary, which will cause testing to be delayed. It is always important to collect the required volume of sample for each test to get accurate results.

A Phlebotomist Is Collecting Sample for a Complete Blood Count