ASCP Phlebotomy MCQ 2 — Questions and Answers
Question 1: What does the term 'hemolysis' refer to in phlebotomy?
- Formation of a blood clot in a vein
- Destruction of red blood cells releasing hemoglobin (Correct answer)
- Collapse of a vein during blood draw
- Inflammation of a blood vessel
Correct answer: Destruction of red blood cells releasing hemoglobin
Hemolysis is the rupture or destruction of red blood cells, releasing hemoglobin into the serum or plasma, which can interfere with many laboratory test results.
Hemolysis occurs when red blood cells are damaged and their contents (primarily hemoglobin) are released into the surrounding serum or plasma, giving it a pinkish-red appearance. In phlebotomy, hemolysis is commonly caused by using a needle that is too small, drawing blood too quickly, mixing tubes too vigorously, or using expired tubes. Hemolyzed specimens can falsely elevate potassium, LDH, AST, iron, and magnesium levels.
Question 2: Which of the following actions helps prevent a hematoma during venipuncture?
- Applying pressure after needle removal for at least 3-5 minutes (Correct answer)
- Bending the arm immediately after the draw
- Removing the tourniquet after removing the needle
- Using the largest gauge needle available
Correct answer: Applying pressure after needle removal for at least 3-5 minutes
Applying direct pressure to the puncture site for 3-5 minutes after needle removal is the primary method to prevent hematoma formation.
A hematoma is a collection of blood beneath the skin caused by blood leaking from the puncture site. Applying firm, direct pressure for 3-5 minutes (longer for patients on anticoagulants) compresses the vein and allows a platelet plug to form. Bending the arm actually increases the risk of hematoma by reopening the puncture site. The tourniquet must always be removed before the needle.
Question 3: The term 'phlebotomy' is derived from Greek words meaning what?
- Blood and vessel
- Vein and incision (Correct answer)
- Needle and skin
- Blood and test
Correct answer: Vein and incision
Phlebotomy comes from the Greek words 'phlebo' (vein) and 'tomy' (incision or cut), literally meaning to cut into a vein.
The word phlebotomy is derived from two Greek roots: 'phleps' or 'phlebo' meaning vein, and 'tome' or 'tomy' meaning to cut or incise. Historically, phlebotomy referred to therapeutic bloodletting. In modern healthcare, the term refers to the practice of drawing blood for diagnostic testing, blood donation, or therapeutic purposes.
Question 4: Which department is responsible for performing blood typing and crossmatching?
- Chemistry
- Hematology
- Blood bank (immunohematology) (Correct answer)
- Microbiology
Correct answer: Blood bank (immunohematology)
The blood bank (immunohematology) department is responsible for blood typing, crossmatching, antibody screening, and ensuring compatible blood products for transfusion.
The blood bank, also known as immunohematology or transfusion services, handles all testing related to blood transfusion including ABO and Rh typing, antibody identification, and crossmatching. Specimens for blood bank require special identification procedures including comparing the patient's wristband information with the requisition form. Mislabeled blood bank specimens are always rejected.
Question 5: What should a phlebotomist do if a patient begins to faint during a blood draw?
- Complete the draw quickly and then attend to the patient
- Remove the tourniquet and needle immediately and lower the patient's head (Correct answer)
- Ask the patient to take deep breaths and continue drawing
- Call a code blue immediately
Correct answer: Remove the tourniquet and needle immediately and lower the patient's head
If a patient shows signs of fainting, the phlebotomist must immediately discontinue the draw by removing the tourniquet and needle, apply pressure, and lower the patient's head.
Syncope (fainting) during phlebotomy is a vasovagal response triggered by anxiety, pain, or the sight of blood. The phlebotomist must immediately: remove the tourniquet, withdraw the needle and apply pressure, lower the patient's head between their knees (if seated) or recline the patient, apply a cold compress, and use ammonia inhalants if needed. Never leave a fainting patient unattended.
Question 6: EDTA prevents blood from clotting by which mechanism?
- Inhibiting thrombin activity
- Chelating (binding) calcium ions (Correct answer)
- Deactivating platelet aggregation
- Neutralizing fibrinogen
Correct answer: Chelating (binding) calcium ions
EDTA prevents clotting by chelating calcium ions, which are essential cofactors in the coagulation cascade.
EDTA works as an anticoagulant by binding (chelating) calcium ions (Ca2+) in the blood. Calcium is required at multiple steps of the coagulation cascade. By removing free calcium, EDTA prevents the cascade from proceeding. EDTA is the preferred anticoagulant for hematology testing (CBC, differential) because it preserves cell morphology and prevents platelet clumping.
ASCP Phlebotomy MCQ 2
What does the term 'hemolysis' refer to in phlebotomy?