American Society for Clinical Pathology Flashcards

Which vein is most commonly selected for routine venipuncture according to ASCP phlebotomy guidelines?

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.

When using the evacuated tube system, what is the correct action if blood stops flowing before the tube is full?

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.

According to ASCP standards, the maximum time a tourniquet should remain applied before venipuncture is performed is:

Answer: 1 minute

Tourniquet application should not exceed 1 minute to prevent hemoconcentration and erroneous lab results.

A patient is on warfarin therapy. Which post-venipuncture action requires special attention?

Answer: Holding pressure longer to prevent hematoma formation

Anticoagulant therapy impairs clotting, so extended pressure application is critical to prevent hematoma.

Which ASCP-recommended needle gauge is standard for routine adult venipuncture?

Answer: 21 gauge

21-gauge needles are the standard for routine adult venipuncture, balancing flow rate and patient comfort.

What condition can result from excessive fist pumping by a patient during venipuncture?

Answer: Pseudohyperkalemia

Repeated fist pumping causes potassium to leak from muscle cells, falsely elevating serum potassium (pseudohyperkalemia).

ASCP guidelines state that a blood culture collection site must be disinfected using which two-step process?

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.