Certified Phlebotomy Technician Exam Routine Collection Procedures 4 — Questions and Answers
Question 1: What is the primary vein of choice for routine venipuncture in adults?
- Cephalic vein
- Basilic vein
- Median cubital vein (Correct answer)
- Median antebrachial vein
Correct answer: Median cubital vein
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?
- Hemolysis of red blood cells
- Falsely prolonged clotting times (Correct answer)
- Specimen clotting
- Elevated potassium results
Correct answer: Falsely prolonged clotting times
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?
- Pumping causes veins to collapse
- Repeated pumping elevates potassium levels, affecting results (Correct answer)
- Pumping increases the risk of hemolysis
- Fist pumping is only appropriate for pediatric patients
Correct answer: Repeated pumping elevates potassium levels, affecting results
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?
- The median cubital vein is visible
- The vein is near the brachial artery and median nerve (Correct answer)
- The patient is elderly
- The patient is right-handed
Correct answer: The vein is near the brachial artery and median nerve
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?
- Sodium
- Glucose
- Potassium (Correct answer)
- Cholesterol
Correct answer: Potassium
Red blood cells contain high intracellular potassium; hemolysis releases this potassium into the serum, falsely elevating results.
Question 6: In the order of draw, which tube comes IMMEDIATELY after the blood culture bottles?
- EDTA (lavender top)
- Sodium citrate (light blue top) (Correct answer)
- Serum tube (red or gold top)
- Sodium fluoride (gray top)
Correct answer: Sodium citrate (light blue top)
Sodium citrate tubes follow blood cultures in the order of draw to avoid carryover contamination affecting coagulation tests.
Question 7: What does the term 'hemoconcentration' refer to in phlebotomy?
- Red blood cell destruction during collection
- Concentration of blood components due to prolonged tourniquet use (Correct answer)
- Dilution of blood by excessive tissue fluid
- Clotting of blood in the collection tube
Correct answer: Concentration of blood components due to prolonged tourniquet use
Prolonged tourniquet application (>1 minute) causes fluid to shift into tissues, concentrating blood cells and large molecules.
Certified Phlebotomy Technician Exam Routine Collection Procedures 4
What is the primary vein of choice for routine venipuncture in adults?