Specimen Collection Techniques Flashcards

What angle should the needle be inserted at during a standard venipuncture?

Answer: 15–30 degrees

A 15–30 degree angle of needle insertion allows access into the vein lumen while minimizing the risk of going through the vein.

Which additive is found in a royal blue-top tube used for trace element testing?

Answer: EDTA or no additive (metal-free)

Royal blue-top tubes contain either EDTA or no additive and are made of metal-free materials to prevent contamination of trace element assays.

A tourniquet should be released no later than how long after application?

Answer: 1 minute

A tourniquet left on longer than 1 minute causes hemoconcentration and can alter analyte concentrations in the specimen.

When performing a heel stick on a newborn, which area of the heel is the CORRECT puncture site?

Answer: The medial or lateral plantar surface

CLSI guidelines specify the medial or lateral plantar surface of the heel to avoid the calcaneus bone and posterior tibial artery.

A patient's vein collapses during blood draw with an evacuated tube. The best corrective action is to:

Answer: Switch to a syringe or butterfly with less vacuum

Reducing vacuum by using a syringe or butterfly set allows gentler aspiration that prevents vein collapse.

Sodium citrate tubes (light blue top) must be filled to the correct volume because:

Answer: The citrate-to-blood ratio must be exactly 1:9

Coagulation tests require a precise 1:9 anticoagulant-to-blood ratio; under- or overfilling invalidates PT and PTT results.

Which of the following correctly describes the proper bevel position at the start of venipuncture?

Answer: Bevel facing up toward the ceiling

The bevel should face up so the needle enters the vein smoothly, allowing blood to flow freely into the lumen.