CPCT Phlebotomy and Specimen Collection 1 — Questions and Answers
Question 1: Which vein is most commonly used for venipuncture in adults?
- Cephalic vein
- Median cubital vein (Correct answer)
- Basilic vein
- Brachial vein
Correct answer: Median cubital vein
The median cubital vein is preferred for venipuncture because it is large, well-anchored, and poses the least risk of injury to surrounding structures.
Question 2: What does the acronym 'SST' stand for in phlebotomy?
- Standard Serum Tube
- Serum Separator Tube (Correct answer)
- Sodium Sample Tube
- Sterile Specimen Tube
Correct answer: Serum Separator Tube
SST stands for Serum Separator Tube, which contains a gel that separates serum from blood cells after centrifugation.
Question 3: What is the correct angle for needle insertion during venipuncture?
- 5 to 10 degrees
- 15 to 30 degrees (Correct answer)
- 45 to 60 degrees
- 70 to 90 degrees
Correct answer: 15 to 30 degrees
A 15 to 30 degree angle is recommended for venipuncture to allow the needle to enter the vein without passing through it.
Question 4: Which color-coded tube top is used to collect blood for a complete blood count (CBC)?
- Red
- Green
- Lavender (purple) (Correct answer)
- Blue
Correct answer: Lavender (purple)
Lavender-top tubes contain EDTA, an anticoagulant that preserves cellular components, making them ideal for CBC testing.
Question 5: How long should a tourniquet remain applied during venipuncture?
- No longer than 1 minute (Correct answer)
- No longer than 3 minutes
- No longer than 5 minutes
- Up to 10 minutes
Correct answer: No longer than 1 minute
A tourniquet should not remain in place for more than 1 minute to prevent hemoconcentration and falsely elevated lab values.
Question 6: What is the correct order of draw when collecting multiple tubes during venipuncture?
- Blood cultures, green, lavender, red
- Blood cultures, red/SST, green, lavender (Correct answer)
- Lavender, red, green, blood cultures
- Red, lavender, blood cultures, green
Correct answer: Blood cultures, red/SST, green, lavender
The correct order of draw is blood cultures first, then red/SST, followed by green (heparin), then lavender (EDTA) to prevent cross-contamination of additives.
Question 7: Which site should be avoided for venipuncture in a patient with a mastectomy on the left side?
- Right arm
- Left arm (Correct answer)
- Right hand
- Either foot
Correct answer: Left arm
The arm on the same side as a mastectomy should be avoided because lymph node removal impairs circulation and increases the risk of infection and lymphedema.
CPCT Phlebotomy and Specimen Collection 1
Which vein is most commonly used for venipuncture in adults?