Phlebotomy Test American Society for Clinical Pathology 3 — Questions and Answers
Question 1: Which vein is most commonly selected for routine venipuncture according to ASCP phlebotomy guidelines?
- Cephalic vein
- Median cubital vein (Correct answer)
- Basilic vein
- Femoral vein
Correct answer: Median cubital vein
The median cubital vein is the preferred first choice for venipuncture because it is large, well-anchored, and typically less painful.
Question 2: When using the evacuated tube system, what is the correct action if blood stops flowing before the tube is full?
- Remove the needle and switch arms immediately
- Gently rotate the tube and slightly advance or retract the needle (Correct answer)
- Apply more tourniquet pressure
- Discard the tube and start over from the beginning
Correct answer: Gently rotate the tube and slightly advance or retract the needle
Gently adjusting needle position and rotating the tube can restore blood flow without restarting the draw.
Question 3: According to ASCP standards, the maximum time a tourniquet should remain applied before venipuncture is performed is:
- 30 seconds
- 1 minute (Correct answer)
- 2 minutes
- 3 minutes
Correct answer: 1 minute
Tourniquet application should not exceed 1 minute to prevent hemoconcentration and erroneous lab results.
Question 4: A patient is on warfarin therapy. Which post-venipuncture action requires special attention?
- Applying a cold pack immediately
- Holding pressure longer to prevent hematoma formation (Correct answer)
- Using a larger-gauge needle for faster draw
- Asking the patient to pump their fist repeatedly
Correct answer: Holding pressure longer to prevent hematoma formation
Anticoagulant therapy impairs clotting, so extended pressure application is critical to prevent hematoma.
Question 5: Which ASCP-recommended needle gauge is standard for routine adult venipuncture?
- 18 gauge
- 21 gauge (Correct answer)
- 25 gauge
- 27 gauge
Correct answer: 21 gauge
21-gauge needles are the standard for routine adult venipuncture, balancing flow rate and patient comfort.
Question 6: What condition can result from excessive fist pumping by a patient during venipuncture?
- Hemodilution
- Pseudohyperkalemia (Correct answer)
- Thrombocytopenia
- Hypoglycemia
Correct answer: Pseudohyperkalemia
Repeated fist pumping causes potassium to leak from muscle cells, falsely elevating serum potassium (pseudohyperkalemia).
Question 7: ASCP guidelines state that a blood culture collection site must be disinfected using which two-step process?
- Povidone-iodine then 70% isopropyl alcohol
- 70% isopropyl alcohol followed by chlorhexidine or povidone-iodine allowed to dry (Correct answer)
- Soap and water followed by 70% alcohol
- Hydrogen peroxide then betadine
Correct answer: 70% isopropyl alcohol followed by chlorhexidine or povidone-iodine allowed to dry
Blood culture sites require a two-step antiseptic scrub—70% alcohol then chlorhexidine gluconate or povidone-iodine—allowed to fully dry before puncture.
Phlebotomy Test American Society for Clinical Pathology 3
Which vein is most commonly selected for routine venipuncture according to ASCP phlebotomy guidelines?