Free NPS Specimen Collection & Handling Questions and Answers — Questions and Answers
Question 1: Which of the following is the most common site for venipuncture?
- Radial vein
- Cephalic vein
- Median cubital vein (Correct answer)
- Femoral vein
Correct answer: Median cubital vein
The median cubital vein, located in the antecubital fossa (the bend of the elbow), is the most common and preferred site for venipuncture. It is typically large, well-anchored, and easily accessible, making it ideal for drawing blood samples with minimal discomfort and risk. Other veins like the cephalic and basilic veins are also used but are often secondary choices.
Question 2: Which tube color is used for coagulation tests?
- Red
- Green
- Light blue (Correct answer)
- Lavender
Correct answer: Light blue
The light blue top tube contains sodium citrate, an anticoagulant that works by binding calcium, which is essential for blood clotting. This specific anticoagulant is critical for coagulation tests (e.g., PT, PTT) because it preserves the clotting factors in their natural state. This allows for accurate assessment of the patient's clotting ability without premature clotting in the sample.
Question 3: What is the correct order of draw when using multiple collection tubes?
- Red, lavender, blue, green
- Blue, red, green, lavender (Correct answer)
- Lavender, red, green, blue
- Green, blue, red, lavender
Correct answer: Blue, red, green, lavender
The correct order of draw is crucial to prevent cross-contamination of additives between collection tubes, which could lead to inaccurate test results. The sequence Blue, Red, Green, Lavender follows the standard guidelines, prioritizing tubes based on their additives and potential for interference with subsequent tests. This specific order ensures the integrity of each sample for its intended analysis.
Question 4: How long should a tourniquet be applied during blood collection?
- 2–3 minutes
- 1 minute or less (Correct answer)
- 5 minutes
- Until blood flow stops
Correct answer: 1 minute or less
A tourniquet should be applied for no longer than 1 minute during venipuncture. Prolonged application can lead to hemoconcentration, where blood components become more concentrated, potentially altering test results. It can also cause patient discomfort, nerve damage, or petechiae.
Question 5: Which of the following is essential when labeling a specimen?
- Room number only
- Collector’s license number
- Test requested only
- Patient ID and collection details (Correct answer)
Correct answer: Patient ID and collection details
Accurate labeling of a specimen with patient identification and collection details is paramount for patient safety and accurate diagnosis. Mislabeling can lead to serious medical errors, including incorrect treatment or diagnosis, making it a critical step in the collection process. Essential information typically includes the patient's full name, date of birth, medical record number, date and time of collection, and the collector's initials.
Question 6: Which condition can result from improper mixing of anticoagulant tubes?
- Hemolysis
- Clotting (Correct answer)
- Contamination
- Dehydration
Correct answer: Clotting
Anticoagulant tubes contain substances designed to prevent blood from clotting, which is necessary for many laboratory tests. If these tubes are not properly mixed immediately after collection, the anticoagulant may not fully disperse throughout the blood sample, leading to partial or complete clotting of the specimen. A clotted sample is unsuitable for tests requiring whole blood or plasma, rendering it unusable.
Question 7: How should specimens requiring refrigeration be handled?
- Leave at room temperature
- Store in sunlight
- Refrigerate with ice pack (Correct answer)
- Freeze immediately
Correct answer: Refrigerate with ice pack
Specimens requiring refrigeration must be kept at a specific cold temperature to preserve their integrity and prevent the degradation of analytes. Using an ice pack during refrigeration helps maintain a consistent cold temperature, ensuring the sample remains stable and its components are preserved until it can be processed in the laboratory. This prevents inaccurate results due to sample deterioration.
Question 8: Which type of specimen is collected for urinalysis?
- First void of day
- Midstream clean-catch (Correct answer)
- 24-hour pooled sample
- Random sample post-lunch
Correct answer: Midstream clean-catch
A midstream clean-catch urine sample is the preferred method for urinalysis to minimize contamination from external genitalia and the initial flow of urine. This technique involves cleaning the urethral area and collecting urine from the middle portion of the void, which helps ensure the collected sample accurately reflects the contents of the bladder. This leads to more reliable diagnostic results by reducing extraneous bacteria or cells.
Question 9: What is the purpose of using a tourniquet during venipuncture?
- Increase blood pressure
- Prevent bleeding
- Make vein more visible (Correct answer)
- Stop infection
Correct answer: Make vein more visible
The primary purpose of applying a tourniquet during venipuncture is to temporarily impede venous blood flow, causing blood to pool in the veins. This makes the veins more prominent, engorged, and easier to palpate and visualize, facilitating successful needle insertion. It helps the phlebotomist locate a suitable vein more efficiently.
Free NPS Specimen Collection & Handling Questions and Answers
Which of the following is the most common site for venipuncture?