Certified Phlebotomy Technician Exam Phlebotomy Fundamentals 3 — Questions and Answers
Question 1: What is the primary purpose of inverting tubes after collection?
- To warm the specimen for processing
- To mix the anticoagulant or additive with blood (Correct answer)
- To prevent hemolysis
- To separate serum from cells
Correct answer: To mix the anticoagulant or additive with blood
Gentle inversion ensures the additive is thoroughly mixed with the blood to prevent clotting or inadequate preservation.
Question 2: Which vein is considered the FIRST choice for routine venipuncture?
- Cephalic vein
- Basilic vein
- Median cubital vein (Correct answer)
- Dorsal metacarpal vein
Correct answer: Median cubital vein
The median cubital vein is largest, most stable, and least painful, making it the preferred site for routine draws.
Question 3: A gray-top tube contains sodium fluoride. What is its primary purpose?
- To prevent platelet aggregation
- To inhibit glycolysis and preserve glucose levels (Correct answer)
- To chelate calcium ions
- To activate clotting factors
Correct answer: To inhibit glycolysis and preserve glucose levels
Sodium fluoride inhibits the enzymes responsible for glycolysis, preserving glucose concentration in the specimen.
Question 4: How long should a tourniquet be left on before venipuncture is performed?
- No more than 1 minute (Correct answer)
- 2–3 minutes
- 5 minutes
- As long as needed to find the vein
Correct answer: No more than 1 minute
Leaving a tourniquet on longer than 1 minute causes hemoconcentration and alters test results.
Question 5: What condition requires a phlebotomist to avoid the ipsilateral arm for venipuncture?
- Mild dehydration
- Presence of a mastectomy on that side (Correct answer)
- History of fainting
- Low platelet count
Correct answer: Presence of a mastectomy on that side
After a mastectomy, lymph node removal compromises drainage on that side, increasing infection and lymphedema risk with any puncture.
Question 6: Which of the following BEST describes 'petechiae' as a phlebotomy complication concern?
- Small red spots indicating capillary hemorrhage under the skin (Correct answer)
- Bruising caused by a missed vein
- Nerve damage from needle insertion
- Inflammation of the vein wall
Correct answer: Small red spots indicating capillary hemorrhage under the skin
Petechiae are tiny red dots caused by capillary rupture and may indicate a bleeding or platelet disorder the phlebotomist should document.
Question 7: In the order of draw, which tube comes immediately AFTER the sodium citrate tube?
- Blood culture bottles
- Serum tube (red or SST) (Correct answer)
- EDTA tube
- Gray-top glucose tube
Correct answer: Serum tube (red or SST)
After the light blue (sodium citrate) tube, the serum tube (red or SST) is drawn next in the established CLSI order of draw.
Certified Phlebotomy Technician Exam Phlebotomy Fundamentals 3
What is the primary purpose of inverting tubes after collection?