CMLA Phlebotomy 4 — Questions and Answers
Question 1: What is the purpose of inverting evacuated tubes after collection?
- To mix the blood with the additive and prevent clotting or ensure proper preservation (Correct answer)
- To remove air bubbles from the tube
- To increase blood volume in the tube
- To separate serum from cells immediately
Correct answer: To mix the blood with the additive and prevent clotting or ensure proper preservation
Gentle inversion mixes blood with anticoagulants or clot activators to ensure proper specimen processing.
Question 2: A patient on anticoagulant therapy has veins that are difficult to locate. Which technique is most appropriate?
- Use a butterfly needle and select the best visible vein, applying gentle pressure after collection (Correct answer)
- Apply the tourniquet longer to distend the vein
- Use a larger gauge needle to improve blood flow
- Attempt venipuncture at the wrist artery
Correct answer: Use a butterfly needle and select the best visible vein, applying gentle pressure after collection
Butterfly needles offer more control in difficult draws, and gentle post-draw pressure is critical because anticoagulated patients bleed longer.
Question 3: Blood cultures should ideally be collected:
- Before antibiotic therapy begins, using strict aseptic technique (Correct answer)
- After the first dose of antibiotics
- From an IV line in place for less than 24 hours
- Using EDTA tubes to prevent coagulation
Correct answer: Before antibiotic therapy begins, using strict aseptic technique
Collecting blood cultures before antibiotics maximizes the chance of isolating the causative organism before antimicrobial agents reduce bacterial counts.
Question 4: Which condition is characterized by involuntary muscle contractions in the arm during or after venipuncture and may result from hyperventilation?
- Tetany (Correct answer)
- Hematoma
- Petechiae
- Edema
Correct answer: Tetany
Hyperventilation causes hypocapnia and respiratory alkalosis, lowering ionized calcium and triggering tetanic muscle spasms.
Question 5: For a timed specimen such as a fasting glucose, what information is most critical to document?
- The exact time of collection and patient's last food/drink intake (Correct answer)
- The color of the tube used
- The gauge of the needle used
- The phlebotomist's employee ID only
Correct answer: The exact time of collection and patient's last food/drink intake
Timed specimens require accurate collection time and fasting duration to ensure clinically valid interpretation of results.
Question 6: What is the primary reason for using a winged infusion set (butterfly) in pediatric or geriatric patients?
- Greater control and flexibility for small or fragile veins (Correct answer)
- Faster blood collection than evacuated tubes
- Larger gauge for higher flow rate
- Elimination of the need for an order of draw
Correct answer: Greater control and flexibility for small or fragile veins
Butterfly needles allow the phlebotomist to stabilize the needle more precisely in small or delicate veins, reducing the risk of through-puncture.
Question 7: A specimen labeled 'STAT' requires:
- Immediate processing and reporting to the ordering provider (Correct answer)
- Processing within 4 hours
- Batch processing at the end of the shift
- Refrigeration until the routine run
Correct answer: Immediate processing and reporting to the ordering provider
STAT orders indicate urgent clinical need and must be processed immediately to provide timely results for patient care decisions.
CMLA Phlebotomy 4
What is the purpose of inverting evacuated tubes after collection?