Certified Phlebotomy Technician Exam Routine Collection Procedures 4

Question 1

What is the primary vein of choice for routine venipuncture in adults?

Accepted Answer

Median cubital vein

Answer

The median cubital vein is the preferred site because it is large, well-anchored, and least likely to roll or cause complications.

Question 2

A light blue-top sodium citrate tube has an incorrect blood-to-additive ratio. What is the MOST likely consequence?

Accepted Answer

Falsely prolonged clotting times

Answer

Excess anticoagulant relative to blood dilutes clotting factors, causing falsely prolonged PT and aPTT results.

Question 3

Why is it important to ask a patient to make a fist but NOT pump it repeatedly before venipuncture?

Accepted Answer

Repeated pumping elevates potassium levels, affecting results

Answer

Repeated fist pumping causes pseudohyperkalemia by releasing potassium from muscle cells into the bloodstream.

Question 4

Which of the following conditions is a contraindication for using the basilic vein?

Accepted Answer

The vein is near the brachial artery and median nerve

Answer

The basilic vein lies close to the brachial artery and median nerve, increasing risk of arterial puncture or nerve injury.

Question 5

A hemolyzed specimen is most likely to cause erroneously elevated results for which analyte?

Accepted Answer

Potassium

Answer

Red blood cells contain high intracellular potassium; hemolysis releases this potassium into the serum, falsely elevating results.

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