Phlebotomy and Specimen Collection Flashcards

A patient is on anticoagulant therapy. Which complication is MOST likely after venipuncture?

Answer: Prolonged bleeding

Anticoagulants impair the blood's clotting ability, so patients on these medications are at increased risk for prolonged bleeding at the puncture site.

Which condition would require a medical assistant to collect a capillary specimen rather than a venous specimen?

Answer: Neonate requiring glucose testing

Neonates have very small, fragile veins, making capillary (heel stick) collection the preferred and safest method for routine testing.

What does hemolysis in a specimen cause, and how can it be prevented?

Answer: Falsely elevated potassium; avoid vigorous mixing and use proper technique

Ruptured red blood cells release intracellular potassium, causing falsely elevated potassium results; gentle technique and proper needle size prevent hemolysis.

When collecting a urine culture specimen, which collection method is MOST appropriate to minimize contamination?

Answer: Midstream clean-catch in a sterile container

A midstream clean-catch method minimizes contamination from skin flora and provides an accurate sample for culture and sensitivity testing.

Which additive is found in a gray-top tube and what test is it primarily used for?

Answer: Sodium fluoride/potassium oxalate; used for glucose testing

Gray-top tubes contain sodium fluoride, which inhibits glycolysis, preserving glucose levels for accurate fasting glucose or GTT testing.

A medical assistant notices a hematoma forming at the venipuncture site during the draw. What should they do?

Answer: Remove the needle immediately and apply firm pressure

A forming hematoma indicates blood is leaking into surrounding tissue; the needle must be removed immediately and pressure applied to stop the bleeding.

What is the maximum time a tourniquet should remain in place during venipuncture to prevent hemoconcentration?

Answer: 1 minute

A tourniquet left in place longer than one minute causes hemoconcentration, which can falsely elevate results for proteins, cells, and other analytes.