ASPT Specimen Collection Techniques 2 — Questions and Answers
Question 1: Which gauge needle is most commonly used for routine adult venipuncture?
- 16 gauge
- 18 gauge
- 21 gauge (Correct answer)
- 25 gauge
Correct answer: 21 gauge
A 21-gauge needle is the standard choice for routine adult venipuncture, balancing adequate flow with minimal vein trauma.
Question 2: When collecting blood cultures, which site should be cleansed first?
- The anaerobic bottle top
- The aerobic bottle top
- The venipuncture site (Correct answer)
- The patient's arm
Correct answer: The venipuncture site
The venipuncture site skin must be disinfected before the bottle tops to prevent contamination of the blood culture.
Question 3: A phlebotomist notices a hematoma forming during venipuncture. The correct immediate action is to:
- Continue drawing and apply pressure after
- Remove the needle immediately and apply firm pressure (Correct answer)
- Redirect the needle to find a better vein
- Increase the vacuum by switching to a larger tube
Correct answer: Remove the needle immediately and apply firm pressure
A forming hematoma indicates blood leaking into tissue; the needle must be removed immediately and firm pressure applied.
Question 4: What is the purpose of inverting collection tubes after blood draw?
- To activate clotting faster
- To cool the specimen
- To mix the additive with blood (Correct answer)
- To prevent hemolysis
Correct answer: To mix the additive with blood
Inverting tubes mixes the anticoagulant or additive evenly with the blood to ensure proper specimen integrity.
Question 5: The antecubital fossa is the preferred venipuncture site because:
- It has smaller veins that are easier to access
- It contains large, accessible veins close to the surface (Correct answer)
- It is less painful than the hand
- It is the only site approved by ASPT
Correct answer: It contains large, accessible veins close to the surface
The antecubital fossa houses the median cubital, cephalic, and basilic veins, which are large, superficial, and stable.
Question 6: Which of the following is a sign of a patent vein suitable for venipuncture?
- Soft, bouncy, and visible or palpable (Correct answer)
- Hard and cord-like on palpation
- Rolls easily away from the needle
- Feels warm and is reddened
Correct answer: Soft, bouncy, and visible or palpable
A patent vein feels soft and bouncy when palpated and springs back under pressure, indicating good blood flow.
Question 7: During a capillary puncture on a finger, the FIRST drop of blood should be:
- Collected into the first microtainer
- Used to fill the EDTA tube
- Wiped away with dry gauze (Correct answer)
- Applied to a blood smear slide
Correct answer: Wiped away with dry gauze
The first drop of blood is wiped away because it contains excess tissue fluid that can contaminate and dilute the specimen.
ASPT Specimen Collection Techniques 2
Which gauge needle is most commonly used for routine adult venipuncture?