Venipuncture and Phlebotomy Flashcards

Which vein is most commonly used for routine venipuncture in adults?

Answer: Median cubital vein

The median cubital vein, located in the antecubital fossa (the inner elbow), is the most commonly used vein for routine venipuncture because it is large, superficial, and well-anchored.

What is the purpose of applying a tourniquet before venipuncture?

Answer: To dilate the veins and make them easier to access

A tourniquet is applied proximal to the venipuncture site to temporarily restrict venous blood flow, causing veins to distend (enlarge) and become more visible and palpable.

In the correct order of draw for multiple tube collection, which tube is collected FIRST?

Answer: Sodium citrate (light blue top)

In the order of draw for multiple tubes, the light blue top (sodium citrate) tube for coagulation studies is drawn first after any discard tube to prevent contamination from additives in other tubes.

What does the term 'hematoma' refer to in the context of phlebotomy?

Answer: A collection of blood that escapes from a vessel into surrounding tissue

A hematoma is a localized swelling caused by blood leaking from a punctured vessel into the surrounding tissue, forming a bruise-like mass under the skin.

Which color top tube is used to collect blood for a complete blood count (CBC)?

Answer: Lavender top (EDTA)

The lavender top tube contains EDTA (ethylenediaminetetraacetic acid), an anticoagulant that preserves blood cell morphology, making it the standard tube for CBCs and other hematology tests.

If a patient is on anticoagulant therapy such as warfarin, what special consideration should the medical assistant take after venipuncture?

Answer: Apply pressure to the site for a longer duration to prevent excessive bleeding

Patients on anticoagulant therapy have impaired clotting ability, so the medical assistant should apply firm pressure for an extended period (5–10 minutes or until bleeding stops) to prevent hematoma or excessive bleeding.