Certified Phlebotomy Technician Exam Phlebotomy Fundamentals 2 — Questions and Answers
Question 1: Which gauge needle is most commonly used for routine venipuncture in adults?
- 16 gauge
- 18 gauge
- 21 gauge (Correct answer)
- 25 gauge
Correct answer: 21 gauge
A 21-gauge needle is the standard for routine adult venipuncture, balancing adequate flow with patient comfort.
Question 2: What is the proper angle of needle insertion for venipuncture?
- 5–10 degrees
- 15–30 degrees (Correct answer)
- 45–60 degrees
- 70–90 degrees
Correct answer: 15–30 degrees
A 15–30 degree angle allows the needle to enter the vein lumen without passing through the posterior wall.
Question 3: Which tube is drawn FIRST in the recommended order of draw?
- EDTA (lavender) tube
- Serum separator tube (SST)
- Blood culture bottles (Correct answer)
- Sodium citrate (light blue) tube
Correct answer: Blood culture bottles
Blood culture bottles are drawn first to minimize contamination risk before any additives are introduced.
Question 4: A patient's arm is edematous at the antecubital fossa. What is the best action?
- Proceed with venipuncture at the same site
- Collect from a finger stick instead
- Select an alternate site such as the forearm or hand (Correct answer)
- Apply extra pressure and draw from the edematous area
Correct answer: Select an alternate site such as the forearm or hand
Edematous tissue traps interstitial fluid that can dilute the specimen, so an alternate unaffected site must be chosen.
Question 5: What does the term 'hemoconcentration' refer to in phlebotomy?
- Increased red blood cell destruction
- Elevation of non-filterable blood components due to fluid shift (Correct answer)
- Decreased platelet count from tourniquet use
- Mixing of venous and arterial blood
Correct answer: Elevation of non-filterable blood components due to fluid shift
Hemoconcentration occurs when a tourniquet is left on too long, causing plasma to shift into tissue and concentrating cellular components.
Question 6: Which additive in the green-top tube prevents clotting by binding calcium?
- EDTA
- Sodium fluoride
- Lithium heparin (Correct answer)
- Sodium citrate
Correct answer: Lithium heparin
Lithium heparin inhibits thrombin and thromboplastin, preventing clot formation without binding calcium directly, but it is the anticoagulant in green-top tubes.
Question 7: A patient reports feeling faint during venipuncture. What is the FIRST action to take?
- Complete the draw as quickly as possible
- Remove the needle and have the patient lower their head or lie down (Correct answer)
- Offer the patient a glass of water
- Apply a cold compress to the puncture site
Correct answer: Remove the needle and have the patient lower their head or lie down
Removing the needle immediately and positioning the patient to improve cerebral blood flow prevents injury from a vasovagal syncope episode.
Certified Phlebotomy Technician Exam Phlebotomy Fundamentals 2
Which gauge needle is most commonly used for routine venipuncture in adults?