ASCP Capillary Puncture and Dermal Collection 2

Question 1

Which lancet is most appropriate for a premature infant requiring a heel stick?

Accepted Answer

A retractable lancet designed for premature neonates with a depth of 0.85 mm or less

Answer

A standard adult fingerstick lancet

Answer

A safety lancet with 2.0 mm depth and 1.5 mm blade

Answer

A surgical scalpel lancet for deeper access

Question 2

Which analyte shows the greatest variation between capillary and venous blood samples?

Accepted Answer

Glucose

Answer

Sodium

Answer

White blood cell count

Answer

Potassium

Question 3

When performing a heel stick on a neonate, where should the puncture NOT be made?

Accepted Answer

Posterior curvature of the heel

Answer

Medial plantar surface

Answer

Lateral plantar surface

Answer

Either medial or lateral plantar surface

Question 4

Why must alcohol be completely dried before performing a capillary puncture?

Accepted Answer

Residual alcohol can hemolyze the specimen and cause a burning sensation

Answer

Wet alcohol causes the lancet to slip during puncture

Answer

Alcohol contamination prevents blood from beading properly on the skin

Answer

Alcohol activates clotting factors prematurely

Question 5

What must be done to a capillary tube used for microhematocrit before centrifugation?

Accepted Answer

Seal one end with clay or a plastic cap

Answer

Label it with a permanent marker on the glass

Answer

Fill it completely to prevent air bubbles

Answer

Wrap it in parafilm to prevent breakage

Question 6

A patient's finger appears cold and cyanotic before a fingerstick. What is the best action?

Accepted Answer

Warm the finger with a warm compress for 3 to 5 minutes

Answer

Proceed with the puncture immediately to avoid delay

Answer

Apply alcohol and wait 60 seconds before puncturing

Answer

Switch to venipuncture instead

Question 7

In the capillary order of draw, which tube is typically collected LAST?

Accepted Answer

Serum separator or plain non-additive tubes

Answer

EDTA (lavender) tube

Answer

Blood gas specimens

Answer

Slides for differential smears