Abarientos, Rozel Dane B.
BSMT 1-1
Ray, a newly hired phlebotomist who has just recently finished phlebotomy training, is
preparing to draw the last GTT specimen on an outpatient. This is the first GTT he has
performed without supervision, and he is proud of how well he has done. The patient has
good veins in both arms so he has been alternating arms for the blood draws. The patient
is anxious to go home and Ray is in a hurry to go on break, so he quickly selects a vein,
performs a successful venipuncture, and collects the required gray-top tube. He finishes
the draw and quickly shakes the tube. Later, as he starts to label it, he notices that the tube
is only half full. He has been allowed to submit other partial tubes without a problem, so
he shrugs his shoulders and proceeds to bandage and then dismiss the patient. He
submits the specimen to the lab and goes on break. When he returns, he is informed that
the last GTT specimen was hemolyzed and unsuitable for testing, so that the test will have
to be repeated. Ray is completely surprised by this because there were no problems with
the draw. Now Ray has to call the patient and reschedule the test. The patient is
understandably upset.
Questions:
1. What errors did Ray make that could have caused hemolysis of the specimen? (5pts)
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Ray mistake was when he shakes the tube that contains additive too quickly/
vigorously. He partially filled a normal draw sodium fluoride tube because he ignored
the fact that the sample was only half full. The amount of blood does not reach the
normal draw arrow and it contains excess sodium fluoride that resulted in hemolysis
of the specimen.
2. What could Ray have done differently that might have prevented the hemolysis? (5pts)
One of the things that Ray should prevent the hemolysis of the specimen is to perform
the procedure accordingly. He should meet the draw amount of the blood needed for
the specimen to prevent hemolysis. In addition, he should also mix the tube that
contains additives carefully to prevent the hemolysis of the sample.
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Ray should perform the procedure accordingly to prevent the specimen to be
hemolyzed. Furthermore, to avoid hemolysis of the specimen, he should draw the
required amount of blood for the specimen and he should gently mix the tube that
contains additive.
3. What is GTT? Why is it important? (5pts)
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Glucose tolerance test is perfomed to test the blood glucose level in the blood and
used to diagnose problems of carbohydrate metabolism because the major
carbohydrate in the blood is glucose, which is the body’s source of energy. GTT also
evaluates the body’s ability to metabolize glucose by monitoring the patient’s
tolerance to high levels of glucose without adverse effects and evaluates the insulin
response to a measured dose of glucose by recording glucose levels on specimens
collected at specific time intervals. GTT is important to test for diabetes, insulin
resistance, impaired beta cell function, reactive hypoglycemia, acromegaly, and other
disorders of carbohydrate metabolism.
4. List down the procedure on how to collect blood samples for GTT. (5pts)
GTT Procedure:
1. Follow normal identification protocol, explain collection procedure and advise
patient that water is allowed but drinking other beverages, eating food, smoking or
chewing gum is not allowed throughout the test
2. Draw fasting specimen and check for glucose
3. Ask the patient to collect a fasting urine specimen if urine testing has been
requested
4. Give the patient the determined dose of glucose beverage
5. remind the patient to finish the beverage within 5 minutes
6. Note the time the patient finishes the beverage, start the timing for the test and
calculate the collection times for the rest of the specimen based on this time.
7. Give a copy of the collection times to the patient
8. Collect blood and urine specimen (if applicable) as close to the computed time as
possible
9. Label all the specimen with the exact time collected and the time interval of the
test in addition to patient identification information
10. Deliver or send specimens to the lab as soon as possible