Certified Phlebotomy Technician Exam General 5 — Questions and Answers
Question 1: What is the purpose of inverting collection tubes after blood collection?
- To separate serum from plasma
- To mix blood with the tube additive (Correct answer)
- To prevent hemolysis
- To activate the clotting process in serum tubes
Correct answer: To mix blood with the tube additive
Gentle inversions ensure the blood mixes thoroughly with the additive (anticoagulant, clot activator, or preservative) to achieve the intended effect.
Question 2: Which of the following is a pre-analytical variable that can affect lab results?
- Analyzer calibration error
- Reagent expiration date
- Patient fasting status (Correct answer)
- Instrument carryover
Correct answer: Patient fasting status
Fasting status affects glucose, lipids, and other analytes, making it a pre-analytical (before testing) variable under the phlebotomist's control.
Question 3: A phlebotomist is unable to locate a vein after two attempts. The BEST next step is to:
- Try a third time on the same arm
- Ask a more experienced colleague or supervisor to attempt the draw (Correct answer)
- Draw from a foot vein without authorization
- Send the patient home and reschedule
Correct answer: Ask a more experienced colleague or supervisor to attempt the draw
Most facilities limit phlebotomists to two attempts; if unsuccessful, another qualified staff member should be asked to attempt the collection.
Question 4: Which term describes the cessation of blood flow from a wound through physiological processes?
- Thrombocytopenia
- Hemostasis (Correct answer)
- Fibrinolysis
- Anticoagulation
Correct answer: Hemostasis
Hemostasis is the body's mechanism to stop bleeding through vasoconstriction, platelet plug formation, and the coagulation cascade.
Question 5: Specimens labeled with a 'STAT' priority should be delivered to the laboratory within:
- 60 minutes
- 30 minutes (Correct answer)
- 5 minutes
- 2 hours
Correct answer: 30 minutes
STAT specimens are urgent and most facilities require delivery and initial processing within 30 minutes of collection.
Question 6: Which of the following identifies the CORRECT definition of 'serum'?
- Whole blood with all cellular components
- Plasma with clotting factors removed after clotting (Correct answer)
- Blood anticoagulated with EDTA
- Red cell concentrate after centrifugation
Correct answer: Plasma with clotting factors removed after clotting
Serum is the liquid portion of blood after it has clotted and been centrifuged, meaning it lacks fibrinogen and other clotting factors.
Question 7: What is the primary reason a tourniquet should not remain on a patient's arm for more than one minute?
- It causes the patient excessive pain
- It leads to hemoconcentration, altering test results (Correct answer)
- It collapses the vein making it unusable
- It increases the risk of hematoma formation
Correct answer: It leads to hemoconcentration, altering test results
Prolonged tourniquet application causes fluid and small molecules to shift out of capillaries, concentrating cells and large analytes like proteins and potassium.
Certified Phlebotomy Technician Exam General 5
What is the purpose of inverting collection tubes after blood collection?