Certified Phlebotomy Technician Special Specimen Collections Questions and Answers — Questions and Answers
Question 1: A phlebotomist needs to collect a specimen for a cold agglutinin test. Which of the following represents the correct handling procedure for this type of sample?
- Place the specimen on a slurry of ice and water immediately after collection.
- Use a standard red-top tube and allow it to cool to room temperature before transport.
- Collect the specimen in a tube that has been warmed to 37°C and keep it at body temperature until tested. (Correct answer)
- Wrap the collection tube in aluminum foil to protect it from light.
Correct answer: Collect the specimen in a tube that has been warmed to 37°C and keep it at body temperature until tested.
Cold agglutinins are antibodies that cause red blood cells to clump together at temperatures below body temperature. To ensure an accurate test result, the specimen must be collected in a pre-warmed tube and maintained at 37°C until the serum can be separated from the cells. Chilling the specimen would cause the agglutinins to attach to the red cells, leading to a falsely decreased result.
Question 2: A phlebotomist is collecting a blood specimen for a legal blood alcohol concentration (BAC) test. Which of the following is a critical step in this procedure?
- Clean the venipuncture site with 70% isopropyl alcohol.
- Use a gray-top tube containing sodium fluoride.
- Follow a strict chain-of-custody documentation protocol. (Correct answer)
- Ask the patient to sign a consent form after the collection is complete.
Correct answer: Follow a strict chain-of-custody documentation protocol.
Specimens collected for legal purposes, such as BAC testing for a court case, require a strict chain-of-custody procedure. This provides a legal record of every person who handled the specimen from collection to analysis, ensuring its integrity and admissibility in court. While a gray-top tube is used, and consent is necessary, the chain of custody is the most critical procedural step unique to legal collections. Cleansing the site with alcohol is contraindicated as it can contaminate the specimen and falsely elevate the result.
Question 3: When performing a blood culture collection, which action is most effective in minimizing the risk of contamination from skin flora?
- Inoculating the anaerobic bottle before the aerobic bottle.
- Using a winged infusion set with a discard tube.
- Applying the tourniquet for less than one minute.
- Scrubbing the site with an appropriate antiseptic and allowing it to fully air-dry. (Correct answer)
Correct answer: Scrubbing the site with an appropriate antiseptic and allowing it to fully air-dry.
Proper skin antisepsis is a critical step to prevent contamination of blood cultures with microorganisms from the skin. This involves vigorously cleaning the site and disinfecting it with an agent like chlorhexidine or iodine, and then allowing the disinfectant to dry completely before venipuncture. Failure to allow adequate drying time is a common cause of contamination.
Question 4: A phlebotomist is collecting a sample for newborn screening on a filter paper card. Which of the following actions would be grounds for specimen rejection?
- Wiping away the first drop of blood after the heel puncture.
- Applying successive drops of blood to fill a single circle. (Correct answer)
- Allowing the blood spots to air-dry in a horizontal position for three hours.
- Touching the filter paper to a large, free-flowing drop of blood.
Correct answer: Applying successive drops of blood to fill a single circle.
For a newborn screening test to be valid, each circle on the filter paper must be saturated with a single drop of blood that soaks through completely. Layering or applying successive drops of blood to the same circle can cause caking, improper saturation, and non-uniform concentration, leading to inaccurate test results and specimen rejection.
Question 5: A patient is scheduled for a glucose tolerance test (GTT). After the fasting blood sample is collected, the patient is given a glucose beverage and instructed to finish it within 5 minutes. What is the phlebotomist's MOST important responsibility regarding the timing of the subsequent draws?
- Start the timer as soon as the patient begins drinking the glucose beverage.
- Record the time the patient finishes the beverage and collect subsequent samples at the specified intervals from that time. (Correct answer)
- Collect the next sample exactly one hour after the fasting draw was completed.
- Adjust the collection times based on how quickly the patient feels the effects of the glucose.
Correct answer: Record the time the patient finishes the beverage and collect subsequent samples at the specified intervals from that time.
For a glucose tolerance test, timing is critical for accurate interpretation. The test timing begins precisely when the patient finishes consuming the glucose beverage. The phlebotomist must accurately document this time and use it as the baseline for collecting all subsequent specimens at the required intervals (e.g., 1-hour, 2-hour).
Question 6: Which of the following tests requires the specimen to be protected from light immediately after collection?
- Lactic Acid
- Ammonia
- Bilirubin (Correct answer)
- Cold Agglutinin
Correct answer: Bilirubin
Bilirubin is a light-sensitive analyte. Exposure to light, especially direct sunlight or artificial light, can cause the bilirubin molecule to break down, leading to falsely low test results. Therefore, specimens for bilirubin testing must be protected from light by wrapping the tube in aluminum foil or using an amber-colored collection tube.
Certified Phlebotomy Technician Special Specimen Collections Questions and Answers
A phlebotomist needs to collect a specimen for a cold agglutinin test.
Which of the following represents the correct handling procedure for this type of sample?