Phlebotomy Flashcards

A PCT is about to collect blood from a patient in isolation for MRSA. Which PPE must be donned BEFORE entering the room?

Answer: Gown and gloves at minimum, per contact precautions

MRSA requires contact precautions, which mandate gown and gloves before entering; N95 is reserved for airborne precautions.

Which specimen must be transported on ice to the laboratory?

Answer: Arterial blood gas (ABG) syringe

ABG specimens must be chilled on ice to stop continued cellular metabolism that would alter pH, pO2, and pCO2 values.

A lavender-top tube is underfilled to only half capacity. Which test will be MOST affected?

Answer: CBC and differential

The EDTA-to-blood ratio is critical for CBC; excess anticoagulant shrinks red cells (echinocytosis) and skews MCV and hematocrit.

When using a butterfly needle for venipuncture, a discard tube should be drawn FIRST when collecting:

Answer: A light blue sodium citrate tube

The dead space in the butterfly tubing contains air that would underfill the citrate tube and alter the 9:1 blood-to-citrate ratio, so a discard tube is drawn first.

Prolonged tourniquet application (>1 minute) can cause:

Answer: Hemoconcentration

Extended tourniquet use causes fluid to shift out of vessels into tissues, concentrating large molecules and cells in the remaining blood.

Which of the following best describes the practice of 'vein palpation'?

Answer: Using the index finger to feel for the vein's bounce and direction before needling

Palpation with the index finger identifies vein depth, direction, and resilience (bounce), which guides successful needle placement.

The gray-top tube contains fluoride and oxalate primarily to:

Answer: Preserve glucose by inhibiting glycolysis

Sodium fluoride inhibits the glycolytic enzymes that would otherwise cause red cells to consume glucose, keeping glucose levels stable for hours.