NCCT Venipuncture Procedures 2 — Questions and Answers
Question 1: Which vein is the preferred first choice for routine venipuncture in the antecubital fossa?
- Basilic vein
- Cephalic vein
- Median cubital vein (Correct answer)
- Dorsal hand vein
Correct answer: Median cubital vein
The median cubital vein is the preferred first choice because it is typically the largest, most anchored, and least painful vein in the antecubital area, with fewer nearby nerves.
The median cubital vein is the vein of choice for venipuncture because of its favorable characteristics: it is located in the center of the antecubital fossa, is typically large and well-anchored by surrounding tissue (less likely to roll), lies close to the surface, and is relatively far from major nerves and the brachial artery.
Question 2: At what angle should the needle be inserted during routine venipuncture?
- 5-10 degrees
- 15-30 degrees (Correct answer)
- 45-60 degrees
- 90 degrees
Correct answer: 15-30 degrees
The needle should be inserted at a 15-30 degree angle with the bevel up. This shallow angle allows smooth entry into the vein without puncturing through the opposite wall.
A 15-30 degree insertion angle is standard for venipuncture. The bevel of the needle faces up to allow the sharpest point to enter the skin and vein cleanly. At this angle, the needle enters the vein at a gradual trajectory, reducing the risk of going through the opposite vein wall.
Question 3: What should the phlebotomist do immediately after removing the needle from the patient's arm?
- Apply the bandage before applying pressure
- Activate the needle safety device and apply pressure to the site with gauze (Correct answer)
- Recap the needle for safe disposal
- Label the tubes before attending to the puncture site
Correct answer: Activate the needle safety device and apply pressure to the site with gauze
Immediately after needle removal, the safety device should be activated and pressure applied to the puncture site with clean gauze to prevent bleeding and hematoma formation.
The sequence after needle removal is critical: apply gauze over the puncture site and instruct the patient to apply firm pressure. Immediately activate the needle's safety engineering control. Dispose of the needle assembly in the sharps container. Check the patient's puncture site. Label tubes at the bedside.
Question 4: When performing venipuncture using the evacuated tube system, what indicates that the needle has entered the vein?
- The patient reports pain
- A flash of blood appears in the hub of the needle or tubing (Correct answer)
- The tube begins to fill automatically
- The tourniquet becomes tighter
Correct answer: A flash of blood appears in the hub of the needle or tubing
A flash of blood in the needle hub or butterfly tubing confirms successful vein entry.
When the needle enters the vein, blood enters the needle lumen and becomes visible as a 'flash' in the translucent hub of the needle (for straight needles) or in the tubing (for butterfly sets). This flash confirms successful venous access before engaging the evacuated tube.
Question 5: Why is it important to release the tourniquet before removing the needle?
- To reduce the patient's pain
- To prevent excessive bleeding and hematoma formation from the pressurized vein (Correct answer)
- To make it easier to remove the needle
- To improve the accuracy of test results
Correct answer: To prevent excessive bleeding and hematoma formation from the pressurized vein
Releasing the tourniquet before removing the needle reduces venous pressure, decreasing the risk of excessive bleeding and hematoma formation at the puncture site.
The tourniquet increases venous pressure by impeding venous return while allowing arterial inflow. If the needle is removed while the tourniquet is still applied, the elevated venous pressure forces blood out of the puncture site more rapidly, increasing the likelihood of hematoma formation and prolonged bleeding.
Question 6: What is the purpose of anchoring the vein during venipuncture?
- To make the vein more visible
- To prevent the vein from rolling away from the needle during insertion (Correct answer)
- To increase blood flow to the area
- To numb the skin before needle insertion
Correct answer: To prevent the vein from rolling away from the needle during insertion
Anchoring the vein with the thumb below the intended puncture site pulls the skin taut and prevents the vein from moving laterally when the needle approaches.
Anchoring involves placing the thumb of the non-dominant hand 1-2 inches below the intended puncture site and pulling the skin taut toward the patient's hand. This stretches the skin to make needle entry less painful and smoother, and it immobilizes the vein so it cannot roll when the needle contacts it.
NCCT Venipuncture Procedures 2
Which vein is the preferred first choice for routine venipuncture in the antecubital fossa?