ASCP Technician for Medical Laboratories 1 — Questions and Answers
Question 1: What is the most important step in ensuring accurate patient identification before venipuncture?
- Asking the patient to state their diagnosis
- Checking the color of the wristband
- Asking the patient to state their full name and date of birth (Correct answer)
- Looking at the room number
Correct answer: Asking the patient to state their full name and date of birth
The most critical step for accurate patient identification before venipuncture is to ask the patient to verbally state their full name and date of birth. This two-factor authentication method directly involves the patient and helps prevent misidentification, ensuring the correct tests are performed on the correct individual. This is a fundamental safety practice in phlebotomy.
Question 2: Which vein is most commonly used for routine venipuncture?
- Basilic vein
- Femoral vein
- Cephalic vein
- Median cubital vein (Correct answer)
Correct answer: Median cubital vein
The median cubital vein, located in the antecubital fossa, is the most commonly used and preferred vein for routine venipuncture. It is typically large, well-anchored, and easily accessible, making it an ideal site for blood collection. Its superficial location and stability contribute to successful venipuncture.
Question 3: What is the correct order of draw when using evacuated tube collection?
- Red, green, lavender, blue
- Blue, red, green, lavender, gray (Correct answer)
- Gray, lavender, green, blue
- Lavender, green, red, blue
Correct answer: Blue, red, green, lavender, gray
The correct order of draw for evacuated tubes is crucial to prevent additive carryover between tubes, which could contaminate specimens and alter test results. The standard order is: blood culture (sterile), light blue (sodium citrate), red/gold/tiger top (serum), green (heparin), lavender (EDTA), and gray (fluoride/oxalate). This sequence minimizes interference with laboratory tests.
Question 4: Which additive is found in the lavender-top tube and what is its function?
- Sodium citrate – anticoagulant
- EDTA – prevents clotting by binding calcium (Correct answer)
- Heparin – inhibits thrombin
- Fluoride – preserves glucose
Correct answer: EDTA – prevents clotting by binding calcium
The lavender-top tube contains EDTA (ethylenediaminetetraacetic acid) as an anticoagulant. EDTA works by binding to calcium ions, which are essential cofactors in the coagulation cascade, thereby effectively preventing blood from clotting. This action preserves cellular components, making it ideal for hematology tests like complete blood counts (CBC).
Question 5: What should a phlebotomy technician do if a patient begins to feel faint during a blood draw?
- Finish the draw quickly
- Instruct the patient to lie down and remove the tourniquet (Correct answer)
- Apply more pressure to the site
- Ignore it and proceed
Correct answer: Instruct the patient to lie down and remove the tourniquet
Removing the tourniquet and assisting the patient to a safe position helps prevent injury from fainting during venipuncture.
Question 6: Which of the following actions may lead to hemolysis of the blood sample?
- Using a small bore needle (Correct answer)
- Allowing alcohol to dry before puncture
- Drawing from a vein without a tourniquet
- Inverting the tubes gently
Correct answer: Using a small bore needle
Small gauge needles can cause red blood cells to rupture due to high pressure during collection, leading to hemolysis.
Question 7: Why should blood cultures be drawn first when performing multiple tests?
- They require the most blood
- They are time-sensitive
- To avoid contamination from other tubes (Correct answer)
- To ensure platelet levels are preserved
Correct answer: To avoid contamination from other tubes
Drawing blood cultures first prevents contamination from additives in other tubes, which could compromise test results.
Question 8: Which of the following is considered a critical step in preventing needlestick injuries?
- Re-capping the needle after use
- Disposing of the needle immediately in a sharps container (Correct answer)
- Leaving the needle on the tray
- Holding the needle while transporting
Correct answer: Disposing of the needle immediately in a sharps container
Immediate disposal of needles into a sharps container helps prevent accidental needlestick injuries and ensures safe handling.
Question 9: What is the primary purpose of the tourniquet during venipuncture?
- Increase patient anxiety
- Constrict arterial flow
- Make veins more prominent and easier to locate (Correct answer)
- Reduce risk of infection
Correct answer: Make veins more prominent and easier to locate
A tourniquet temporarily slows venous blood flow, making the veins more visible and easier to access.
Question 10: How long should pressure be applied to a venipuncture site after removing the needle?
- 5 seconds
- Until the patient says it no longer hurts
- 15 to 30 seconds
- Until bleeding stops (typically 1-2 minutes) (Correct answer)
Correct answer: Until bleeding stops (typically 1-2 minutes)
Pressure must be applied until bleeding ceases to prevent bruising or hematoma formation at the puncture site.
Question 11: Which of the following is the correct procedure for labeling specimens?
- Label all tubes after leaving the patient’s room
- Use only the patient’s initials on the label
- Label the tubes at the bedside immediately after collection (Correct answer)
- Let another staff member label the tubes later
Correct answer: Label the tubes at the bedside immediately after collection
Proper labeling at the point of collection reduces errors and ensures the specimen is accurately matched to the patient.
ASCP Technician for Medical Laboratories 1
What is the most important step in ensuring accurate patient identification before venipuncture?