Question 1

Which of the following is a primary benefit of acquiring capillary blood specimens instead of venipuncture in pediatric patients?

Accepted Answer

It reduces the risk of iatrogenic anemia and nerve damage.

Question 2

Which laboratory test is NOT suitable for capillary blood collection due to sample volume and contamination concerns?

Accepted Answer

Blood cultures

Question 3

Capillary blood differs from venous blood because it is a mixture of which components?

Accepted Answer

Blood from arterioles, venules, capillaries, and interstitial fluids

Question 4

Why is it important to control the depth of incision during a skin puncture procedure?

Accepted Answer

To avoid injury to nerves, tendons, cartilage, and bone

Question 5

Which site is preferred for skin puncture in adults?

Accepted Answer

Fleshy, central palmar surface of the distal phalanx of the third (middle) finger

Question 6

A patient requires a capillary blood sample for a CBC. What is the correct order of tube collection after the first drop is removed?

Accepted Answer

EDTA tubes, then other tubes with additives, then nonadditive tubes

Question 7

Which of the following is a common cause of hemolysis in capillary blood specimens?

Accepted Answer

Excessive milking or massaging of the finger

Question 8

Why should iodine tincture preparations NOT be used to cleanse the skin puncture site?

Accepted Answer

They can falsely elevate potassium, phosphorus, or uric acid determinations.

Question 9

Which of the following statements about capillary blood composition is correct?

Accepted Answer

Arterial pressure is stronger, so capillary blood has a slightly higher proportion of arterial blood.

Question 10

A newborn requires a capillary blood sample. Which site is recommended for the skin puncture?

Accepted Answer

Lateral or medial plantar surface of the heel

Question 11

Which of the following laboratory tests can be performed using capillary blood?

Accepted Answer

Manual WBC differential blood smears

Question 12

What is the recommended depth for skin puncture in adults?

Accepted Answer

2 to 3 mm

Question 13

Which of the following is NOT a recommended supply for skin puncture procedures?

Accepted Answer

Reusable puncture devices

Question 14

A patient’s finger is cold prior to skin puncture. What should be done to improve blood flow?

Accepted Answer

Apply a warm towel at $$42\ ^\circ \mathrm{C}$$ for 3 to 5 minutes

Question 15

Which of the following is a reason to avoid excessive squeezing or massaging during capillary blood collection?

Accepted Answer

It may result in excess tissue fluid and hemolysis.

Question 16

Which of the following statements about blood smears is correct?

Accepted Answer

Slides with ridges, lines, or holes are not useable for blood smears.

Question 17

Which of the following is a contraindication for skin puncture in adults?

Accepted Answer

Need for large amounts of blood for testing

Question 18

Which of the following statements about glucose concentration in capillary blood is true?

Accepted Answer

Glucose concentration is higher in capillary blood than in venous blood.

Question 19

Which anticoagulant is commonly used in tubes for hematology tests collected via capillary blood?

Accepted Answer

Ethylenediamine tetraacetate (EDTA)

Question 20

A capillary blood sample for blood gas determination must be collected with which precaution?

Accepted Answer

Warm the site to increase arterial blood flow and avoid air bubbles in the tube.

Capillary or Dermal Blood Specimens: Principles and Procedures

Study Guide - Practice Questions