Phlebotomy practice questions

Answer: B) Median cubital

• AIncorrect. It is near the nerve and artery.
• BCorrect. It is large, well anchored and less painful.
• CIncorrect. This is not used routinely.
• DIncorrect. This is not used routinely.

Answer: A) 15–30 degrees

• ACorrect. Bevel up, at a shallow angle.
• BIncorrect. This is too steep.
• CIncorrect. This is too steep.
• DIncorrect. This is too flat.

Answer: B) By letting one large drop soak through each circle from one side

• AIncorrect. That gives poor samples.
• BCorrect. Don't touch the circles.
• CIncorrect. It's a filter paper card.
• DIncorrect. Fill each circle completely.

Answer: A) The tube held too little specimen for the ordered tests

QNS stands for quantity not sufficient: the specimen volume is too small for the ordered testing, so a recollection is usually needed.

• ACorrect. QNS means quantity not sufficient: there isn't enough specimen to run the ordered tests. For additive tubes, underfilling can also upset the blood-to-additive ratio.
• BIncorrect. That describes hemolysis, a different reason for rejection. It isn't reported as QNS.
• CIncorrect. A clotted specimen is a separate rejection reason, usually caused by inadequate mixing. It isn't what QNS means.
• DIncorrect. A labeling mismatch is an identification error, not a volume problem. QNS refers only to insufficient quantity.

Answer: B) Apply pressure longer until bleeding stops

• AIncorrect. Pressure is needed.
• BCorrect. Check before bandaging.
• CIncorrect. Direct pressure is better.
• DIncorrect. Check for bleeding.

Answer: D) A butterfly needle with a small tube or syringe

• AIncorrect. That's too long.
• BIncorrect. That's too big.
• CIncorrect. That's for capillary samples.
• DCorrect. Gentle suction helps prevent collapse.

Answer: D) Pull the skin taut with the thumb below the site

To anchor a vein, the technician uses the thumb to pull the skin taut below the puncture site. This keeps the vein from rolling during needle insertion.

• AIncorrect. Repeated fist pumping does not hold the vein still and can change some test results, such as potassium.
• BIncorrect. Tapping may help find a vein, but it does not hold the vein in place, and hard tapping can bruise the site.
• CIncorrect. Pressing above the site blocks the vein in the direction of flow and does not pull the skin taut, so the vein can still roll.
• DCorrect. Pulling the skin taut with the thumb below the puncture site holds the vein in place so it does not roll when the needle goes in.

Answer: C) Light blue (citrate)

• AIncorrect. Several tubes come before it.
• BIncorrect. Gray comes after lavender.
• CCorrect. Citrate comes before EDTA in the order of draw.
• DIncorrect. Order matters.

Answer: A) A vein on the back of the hand, often drawn with a winged (butterfly) set

When the antecubital veins can't be used, the usual alternative is a vein on the back of the hand, often drawn with a butterfly set. Arteries, fistula or graft arms, and foot veins without authorization are not acceptable routine choices.

• ACorrect. After the inside of the elbow, the back of the hand is the usual site for drawing blood. Hand veins are small and close to the surface, so a butterfly set gives better control at a shallow angle. The draw may be more uncomfortable.
• BIncorrect. Foot and ankle veins are not a routine backup site. They carry a higher risk of complications, and most facilities allow them only with a provider's authorization.
• CIncorrect. Routine venous blood tests are not drawn from arteries. Arterial puncture is a separate procedure with its own risks and training requirements.
• DIncorrect. An arm with a vascular graft or other venous access device should not be used for venipuncture. Using it can damage the access and harm the patient.

Answer: A) Excess tissue fluid can dilute the sample and hide veins

Edematous sites are avoided because tissue fluid can dilute the specimen and give inaccurate results, and the swelling makes veins hard to find.

• ACorrect. Fluid in the tissues can mix with the specimen and alter results. The swelling also makes veins hard to see and feel, so another site should be chosen.
• BIncorrect. Hemoconcentration comes from leaving the tourniquet on too long. It isn't why edematous sites are avoided; the concern with edema is dilution by tissue fluid.
• CIncorrect. Edema buries veins deeper under swollen tissue, making them harder to find. It doesn't bring them closer to the surface.
• DIncorrect. Tissue fluid doesn't clot the needle. The problem is contamination and dilution of the specimen.