Phlebotomy Special Collection Procedures Questions and Answers 1 — Questions and Answers
Question 1: A phlebotomist is collecting a trough level specimen for therapeutic drug monitoring (TDM). When should the specimen be collected?
- Immediately after the next dose is administered
- 30 to 60 minutes after the completion of an IV infusion
- At a randomly selected time between doses
- Shortly before the next scheduled dose is administered (Correct answer)
Correct answer: Shortly before the next scheduled dose is administered
A trough level represents the lowest concentration of a drug in the patient's bloodstream. To accurately measure this, the blood should be drawn just before the next dose is given, when the drug level is expected to be at its minimum.
Question 2: During a multi-sample oral glucose tolerance test (GTT), a patient vomits 45 minutes after drinking the glucose beverage. Which of the following is the most appropriate action for the phlebotomist to take?
- Continue the test and note the time of vomiting on the requisition
- Offer the patient water and resume the test from where it left off
- Discontinue the test and immediately notify the patient's physician or nurse (Correct answer)
- Administer a second, smaller dose of the glucose beverage
Correct answer: Discontinue the test and immediately notify the patient's physician or nurse
Vomiting during a GTT invalidates the results because the amount of glucose absorbed cannot be determined. The test must be stopped, and the ordering physician must be notified for further instructions.
Question 3: Which of the following is a critical step in preparing a thick blood smear for malaria diagnosis?
- Fixing the smear with methanol before it air dries
- Using the corner of a clean slide to spread the blood into a dime-sized circle (Correct answer)
- Creating a feathered edge by pushing a spreader slide rapidly and smoothly
- Ensuring the smear is thick enough to obscure newsprint placed underneath it
Correct answer: Using the corner of a clean slide to spread the blood into a dime-sized circle
For a thick smear, a large drop of blood is spread in a circular motion to create a smear about the size of a dime. This technique concentrates the parasites, making them easier to find. Unlike thin smears, thick smears are not fixed with methanol, as this would prevent the red blood cells from lysing, which is necessary for proper examination.
Question 4: A phlebotomist is collecting a blood specimen for a legal proceeding that requires a chain of custody. Which of the following actions is essential to maintain the integrity of the specimen?
- Asking the patient to initial the collection tubes after labeling
- Using a gray-top tube regardless of the test ordered
- Documenting every individual who handles the specimen (Correct answer)
- Having a coworker of the same gender witness the collection
Correct answer: Documenting every individual who handles the specimen
The chain of custody is a legal and procedural document that tracks the specimen from the moment of collection until the results are reported. It requires meticulous documentation of every person who has had possession of the specimen to ensure its integrity and prevent tampering.
Question 5: When collecting a blood spot specimen for newborn screening, which action is considered unacceptable and could lead to specimen rejection?
- Wiping away the first drop of blood after the heel puncture
- Applying blood to only one side of the filter paper
- Allowing a large drop of blood to form before touching it to the paper
- Touching the filter paper directly to the baby's heel to speed up collection (Correct answer)
Correct answer: Touching the filter paper directly to the baby's heel to speed up collection
The filter paper should not be pressed against the puncture site. Instead, a large drop of blood should be allowed to form and then touched gently to the paper, allowing the blood to soak through and completely fill the circle by capillary action. Touching the paper to the skin can cause smearing, contamination, and incomplete saturation.
Question 6: A patient is scheduled for a 2-hour oral glucose tolerance test (GTT). Which instruction is most critical for the phlebotomist to confirm with the patient before starting the test?
- Have you consumed a high-protein breakfast this morning?
- Have you been fasting for at least 8 hours? (Correct answer)
- Did you perform strenuous exercise within the last hour?
- Have you avoided all dairy products for the past 24 hours?
Correct answer: Have you been fasting for at least 8 hours?
A GTT requires the patient to be in a basal, fasting state to establish a baseline glucose level. The standard protocol requires the patient to fast (no food or drink, except water) for at least 8 to 14 hours before the test begins.
Phlebotomy Special Collection Procedures Questions and Answers 1
A phlebotomist is collecting a trough level specimen for therapeutic drug monitoring (TDM).
When should the specimen be collected?