Phlebotomy Test Capillary and Dermal Puncture

Question 1

When performing a fingerstick on an adult patient, which finger is the PREFERRED site?

Accepted Answer

Middle or ring finger

Answer

Thumb

Answer

Index finger

Answer

Little finger

Question 2

Why is the first drop of blood wiped away during a capillary puncture?

Accepted Answer

To remove tissue fluid that could dilute or contaminate the sample

Answer

To ensure adequate blood flow by removing the clot

Answer

To sterilize the puncture site

Answer

To allow the lancet wound to seal partially

Question 3

The correct order of draw for capillary specimens collected in micro-collection tubes is:

Accepted Answer

Blood gases → EDTA → other additive tubes → serum tube

Answer

EDTA → other additive tubes → serum tube

Answer

Serum tube → EDTA → other additive tubes

Answer

Other additive tubes → EDTA → serum tube

Question 4

What is the maximum recommended depth of a heel puncture in a full-term neonate?

Accepted Answer

2.0 mm

Answer

1.0 mm

Answer

2.4 mm

Answer

3.0 mm

Question 5

Which area of the neonatal heel is the CORRECT site for a heelstick?

Accepted Answer

Medial or lateral plantar surface of the heel

Answer

Center of the heel pad (plantar surface)

Answer

Posterior curve of the heel

Answer

Top of the foot near the ankle

Question 6

Warming the fingertip or heel before a capillary puncture primarily serves to:

Accepted Answer

Increase local blood flow (arterialization) for adequate sample collection

Answer

Sterilize the skin surface

Answer

Reduce patient pain during puncture

Answer

Prevent the sample from clotting in the tube

Question 7

A phlebotomist performs a fingerstick and squeezes the finger excessively to obtain enough blood. This practice can cause which test result to be FALSELY ELEVATED?

Accepted Answer

Potassium

Answer

Hemoglobin

Answer

Glucose

Answer

Sodium

Question 8

In capillary puncture, the lancet should be positioned perpendicular to the fingerprint lines. Why?

Accepted Answer

To ensure the wound opens freely and blood flows more easily

Answer

To maximize lancet depth penetration

Answer

To reduce the risk of nerve damage

Answer

To allow the wound to seal faster after collection