Phlebotomy Test Venipuncture Procedures 3 — Questions and Answers
Question 1: Which condition is a contraindication to using the antecubital vein on the same side as a mastectomy?
- Thrombocytopenia
- Lymphedema risk (Correct answer)
- Anemia
- Dehydration
Correct answer: Lymphedema risk
Venipuncture on the same side as a mastectomy risks introducing infection or worsening lymphedema due to compromised lymphatic drainage.
Question 2: What does the term 'anchoring the vein' mean during venipuncture?
- Taping the needle to prevent movement
- Applying downward traction on the skin to stabilize the vein (Correct answer)
- Tightening the tourniquet further
- Pressing on the vein to raise it
Correct answer: Applying downward traction on the skin to stabilize the vein
Anchoring involves pulling the skin taut below the insertion site to stabilize a rolling vein and facilitate smooth needle entry.
Question 3: What angle of needle insertion is recommended for standard adult venipuncture?
- 5–10 degrees
- 15–30 degrees (Correct answer)
- 45 degrees
- 60 degrees
Correct answer: 15–30 degrees
A 15–30 degree angle allows the needle to enter the vein cleanly without going through the back wall.
Question 4: A patient reports feeling faint and breaks into a cold sweat during venipuncture. This is most likely a sign of:
- Anaphylaxis
- Vasovagal syncope (Correct answer)
- Hematoma
- Nerve injury
Correct answer: Vasovagal syncope
Vasovagal syncope is a common reaction characterized by fainting, pallor, diaphoresis, and bradycardia triggered by needle anxiety or pain.
Question 5: Which of the following is the correct way to mix an anticoagulant tube after collection?
- Shake vigorously 10 times
- Gently invert 8–10 times (Correct answer)
- Leave undisturbed for 5 minutes
- Centrifuge immediately without mixing
Correct answer: Gently invert 8–10 times
Gentle inversion 8–10 times ensures the additive is thoroughly mixed with the blood without causing hemolysis.
Question 6: When performing venipuncture on a patient with small or fragile veins, which needle is most appropriate?
- 18-gauge straight needle
- 23-gauge butterfly needle (Correct answer)
- 21-gauge multi-sample needle
- 20-gauge straight needle
Correct answer: 23-gauge butterfly needle
A 23-gauge butterfly (winged infusion) set allows better control and flexibility for difficult or fragile veins.
Question 7: If blood flow stops after initially starting well during venipuncture, which corrective action should be attempted FIRST?
- Remove the needle and try a new site
- Gently rotate the needle 180 degrees (Correct answer)
- Apply additional tourniquet pressure
- Squeeze the patient's fist repeatedly
Correct answer: Gently rotate the needle 180 degrees
Rotating the needle 180 degrees may reposition the bevel away from the vein wall and restore blood flow without restarting the procedure.
Phlebotomy Test Venipuncture Procedures 3
Which condition is a contraindication to using the antecubital vein on the same side as a mastectomy?