Clinical Procedures and Specimen Handling Flashcards

A hemolyzed blood specimen is most likely caused by:

Answer: Drawing blood too slowly through a small-gauge needle

Forcing blood through a small-gauge needle creates shear stress that ruptures red blood cells, causing hemolysis.

Which tube additive is found in a light-blue-topped vacutainer tube used for coagulation studies?

Answer: Sodium citrate

Light-blue tops contain sodium citrate, which chelates calcium to prevent clotting for coagulation tests like PT and PTT.

When performing an intradermal injection for a tuberculin skin test (TST), the correct angle of insertion is:

Answer: 15 degrees

Intradermal injections are administered at a 10-15 degree angle to deposit the solution within the dermis, forming a wheal.

A patient's urine specific gravity is 1.035. This finding most likely indicates:

Answer: Dehydration or highly concentrated urine

Normal specific gravity is 1.001-1.030; a value of 1.035 indicates highly concentrated urine, suggestive of dehydration.

When collecting a stool specimen for occult blood testing, the patient should avoid which food for 3 days prior?

Answer: Red meat

Red meat contains hemoglobin that can cause false-positive results on guaiac-based fecal occult blood tests.

Which personal protective equipment (PPE) is required when handling all laboratory specimens?

Answer: Gloves and face protection as appropriate

Standard precautions require gloves for all specimen handling, with additional PPE (face protection, gown) based on anticipated splash risk.

The bevel of the needle should be positioned facing up during venipuncture because:

Answer: It allows the needle to enter the vein more smoothly and reduces trauma

Bevel-up positioning allows the sharp cutting edge to penetrate the vein wall at the optimal angle with least tissue damage.