Phlebotomy Flashcards

Hemolysis of a blood specimen can cause falsely ELEVATED results for which analyte?

Answer: Potassium

Red blood cells contain high concentrations of potassium; cell lysis releases this intracellular potassium, falsely elevating serum levels.

A patient on anticoagulant therapy has a hematoma forming at the venipuncture site. The PCT should:

Answer: Immediately remove the needle and apply firm pressure for at least 5 minutes

Anticoagulated patients bleed more readily; prompt needle removal and extended pressure prevent serious hematoma expansion.

Which capillary puncture site is preferred for infants under 1 year of age?

Answer: Heel (plantar surface)

Heel puncture on the plantar surface is the standard site for neonates and infants because finger bones are too close to the skin surface.

The maximum depth for a heel stick in a neonate is:

Answer: 2.0 mm

CLSI guidelines limit neonatal heel puncture depth to 2.0 mm to avoid hitting the calcaneus (heel bone) and causing osteomyelitis.

Which tube is used for coagulation studies such as PT and aPTT?

Answer: Light blue top (sodium citrate)

Sodium citrate binds calcium to reversibly inhibit coagulation, preserving clotting factors for accurate coagulation testing.

A phlebotomist notices the tube stopper color and the test requisition do not match. The BEST action is to:

Answer: Stop and clarify with the ordering nurse or provider before collecting

Using the wrong additive tube can invalidate results or harm the patient; clarification before collection is always the safest step.

Why is the first drop of blood from a capillary puncture discarded?

Answer: It may be contaminated with tissue fluid that can dilute or alter results

The initial puncture causes tissue fluid to mix with blood, which can dilute the sample and skew analyte concentrations.