Phlebotomy Test Capillary and Dermal Puncture 3

Question 1

What is the primary reason that EDTA tubes are collected FIRST in the capillary order of draw?

Accepted Answer

To ensure the hematology specimen is collected before platelet clumping and activation occur

Answer

EDTA prevents clotting of the entire collection

Answer

EDTA stabilizes glucose levels in the sample

Answer

Lab policy requires EDTA first regardless of clinical rationale

Question 2

A phlebotomist must collect a capillary sample for neonatal glucose monitoring. The nurse requests a stat result. Which Microtainer tube should be used?

Accepted Answer

Gray (sodium fluoride/potassium oxalate)

Answer

Lavender (EDTA)

Answer

Gold (serum separator)

Answer

Green (lithium heparin)

Question 3

When performing a heelstick on a preterm neonate (born at 28 weeks gestation), the maximum lancet depth should be:

Accepted Answer

0.65 mm (the shallowest commercially available device)

Answer

2.0 mm (same as full-term)

Answer

1.0 mm or less

Answer

No heelstick—always use venipuncture for preterm infants

Question 4

The term 'arterialized capillary blood' refers to blood obtained after:

Accepted Answer

Warming the site to increase local arterial blood flow

Answer

Puncturing a capillary adjacent to an artery

Answer

Using a longer lancet that reaches arterioles

Answer

Applying a tourniquet to concentrate arterial blood

Question 5

Which of the following is the CORRECT technique for applying blood to a newborn screening filter paper card?

Accepted Answer

Touch the blood drop to the center of the circle and allow it to soak through in a single application

Answer

Apply multiple small drops layered on top of each other to fill the circle

Answer

Press the card directly against the heel to collect blood

Answer

Apply blood to the back of the card to prevent evaporation

Question 6

A phlebotomist needs to collect a capillary specimen from a patient with severe bilateral hand edema. The BEST alternative site would be:

Accepted Answer

The earlobe

Answer

The forearm

Answer

The forehead

Answer

The upper arm

Question 7

How long should isopropyl alcohol be allowed to dry before performing a capillary puncture?

Accepted Answer

Until it is completely dry (30–60 seconds)

Answer

5–10 seconds is sufficient

Answer

It does not need to dry—immediately puncture

Answer

At least 5 minutes to ensure complete evaporation

Question 8

In capillary puncture, which of the following causes the LEAST amount of pain and tissue damage while still providing adequate blood?

Accepted Answer

An automated spring-loaded safety lancet of appropriate gauge and depth

Answer

A larger gauge lancet with greater depth

Answer

A manual lancet blade for maximum control

Answer

A 21-gauge needle for precise puncture