NHA Certified Phlebotomy Technician (CPT)Collection RoutineMedium
A phlebotomy technician is preparing to draw blood from a patient with an IV infusion running in the left arm. Which of the following is the most appropriate action?
- ADraw blood from the patient's foot or ankle.
- BDraw blood from the right arm, if suitable.
- CTurn off the IV for 2 minutes, then draw blood from the left arm below the IV.
- DDraw blood from above the IV site in the left arm.
Show answer & explanationAnswer & explanation
Correct answer: B. Draw blood from the right arm, if suitable.
Drawing blood from the opposite arm (right arm, if suitable) is the most appropriate action to prevent dilution of the blood sample by the IV fluid and to avoid potential complications at the IV site.
Why the other options are wrong
- A. Drawing from the foot or ankle is generally avoided due to increased risk of infection and thrombosis, and should only be considered if other sites are unavailable and with physician approval.
- C. While turning off the IV for a short period and drawing below can be done in specific circumstances, it's not the primary best practice and still carries some risk of dilution if not done correctly, and requires a nurse to turn off/on the IV.
- D. Drawing above the IV site is still risky due to potential backflow or contamination from the IV solution.
Venipuncture with IV
When a patient has an IV infusion, venipuncture should ideally be performed on the opposite arm to prevent dilution of the specimen by IV fluids and avoid complications.
- Opposite arm is preferred.
- Avoid drawing above or below an active IV if possible.
- If no other site, IV must be turned off for a period (e.g., 2-5 min) and blood drawn below, then flushed.
Memory trick: IV in one, draw from the other, keep results pure!