RMA Venipuncture and Phlebotomy 3 — Questions and Answers
Question 1: Which gauge needle is most commonly used for routine adult venipuncture?
- 21 gauge (Correct answer)
- 16 gauge
- 25 gauge
- 30 gauge
Correct answer: 21 gauge
A 21-gauge needle is the standard choice, balancing adequate flow with patient comfort.
Question 2: What complication results from drawing blood too quickly or with too small a needle, damaging red cells?
- Hemolysis (Correct answer)
- Hemoconcentration
- Hematoma
- Hemostasis
Correct answer: Hemolysis
Hemolysis is the rupture of red blood cells, which can falsely elevate potassium and other analytes.
Question 3: A bruise that forms at the puncture site due to blood leaking into surrounding tissue is called a:
- Hematoma (Correct answer)
- Petechiae
- Thrombus
- Lipemia
Correct answer: Hematoma
A hematoma forms when blood escapes the vein into nearby tissue, often from a needle passing through the vein.
Question 4: Which tube additive is the anticoagulant of choice for coagulation studies such as PT and PTT?
- Sodium citrate (Correct answer)
- EDTA
- Sodium fluoride
- Clot activator
Correct answer: Sodium citrate
Sodium citrate in the light blue top tube is used for coagulation testing because it reversibly binds calcium.
Question 5: What is the correct blood-to-additive ratio that must be maintained in a sodium citrate tube?
- 9 parts blood to 1 part additive (Correct answer)
- 1 part blood to 9 parts additive
- 5 parts blood to 1 part additive
- Ratio does not matter
Correct answer: 9 parts blood to 1 part additive
Coagulation tubes require a 9:1 blood-to-citrate ratio for accurate results, so they must be filled completely.
Question 6: Before performing a venipuncture, what is the most important step to ensure correct specimen labeling?
- Verify patient identity using two identifiers (Correct answer)
- Label tubes the day before
- Ask a coworker for the name
- Label after the patient leaves
Correct answer: Verify patient identity using two identifiers
Using two patient identifiers prevents specimen mislabeling and serious patient safety errors.
Question 7: If a vein cannot be felt in either arm, what is an acceptable alternative site for venipuncture?
- Veins on the dorsal (back) of the hand (Correct answer)
- The underside of the wrist
- An artery in the wrist
- A vein in a mastectomy-side arm
Correct answer: Veins on the dorsal (back) of the hand
Hand veins are an acceptable alternative, usually requiring a smaller gauge needle or butterfly set.
RMA Venipuncture and Phlebotomy 3
Which gauge needle is most commonly used for routine adult venipuncture?