LABORATORY AND DIAGNOSTIC TESTS.
11TH EDITION
• AUTHOR(S)FRANCES FISCHBACH;
MARGARET FISCHBACH; KATE STOUT
TESTBANKS
Ch. 1 — Diagnostic Testing: Preanalytic Patient Preparation
Stem: A 58-year-old patient is brought to the lab for a fasting
lipid panel but reports having eaten a breakfast sandwich 30
minutes earlier. The phlebotomist asks you (the nurse) whether
the sample should still be collected now. Which action is most
appropriate?
A. Proceed with blood draw and note “nonfasting” on the
requisition.
B. Delay the blood draw and ask the patient to fast for 12 more
hours before collection.
C. Cancel the order because the specimen is now invalid and
cannot be repeated.
,D. Collect the specimen and request the lab to adjust reference
ranges for nonfasting samples.
Correct answer: A
Rationale — Correct (A): The nurse should proceed and clearly
document “nonfasting” on the requisition. Many labs accept
nonfasting specimens with notation; documentation allows the
lab and provider to interpret results appropriately and decide
on repeat testing per guidelines. This preserves care continuity
and avoids delaying diagnostic workup.
Rationale — Incorrect:
B. Unnecessarily delays care; immediate delay without provider
discussion is inappropriate.
C. Cancellation is excessive — the specimen still provides
interpretable data if status is noted.
D. Labs do not retrospectively “adjust” ranges; notation is the
correct step, not range alteration.
Teaching point: Always document nonfasting status;
communicate to provider if fasting result is required.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2024). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
Ch. 1 — Diagnostic Testing: Timing and Diurnal Variation
Stem: A provider orders an early-morning cortisol level to
evaluate adrenal function. The patient was scheduled for blood
draw at 1400 (2:00 PM) due to transportation delays. Which
,statement best reflects nursing action and interpretation?
A. Collect at 1400 and interpret against standard early-morning
reference ranges.
B. Reschedule collection for the next morning before 0900 and
inform the provider.
C. Collect at 1400; cortisol does not vary with time of day.
D. Cancel the test because cortisol cannot be measured reliably.
Correct answer: B
Rationale — Correct (B): Cortisol has a marked diurnal rhythm
(peak in early morning). For diagnostic accuracy, the nurse
should reschedule for a morning draw and notify the provider;
collecting at 1400 would produce a noncomparable value.
Rationale — Incorrect:
A. Collecting at 1400 but using morning reference ranges yields
misleading interpretation.
C. False — cortisol varies significantly by time of day.
D. Unnecessary; the test is reliable if timed correctly.
Teaching point: Time-sensitive tests require collection at
specified times for valid interpretation.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2024). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
Ch. 1 — Diagnostic Testing: Specimen Labeling and Patient
Identification
, Stem: You receive a blood tube at the bedside that a
phlebotomist says was labeled at the nursing station earlier. The
patient’s armband indicates a different birthdate than the tube
label. Which is the best nursing response?
A. Accept the tube because the name matches, then note the
discrepancy on the chart.
B. Reject the specimen and request immediate recollection
after bedside positive identification.
C. Correct the birthdate on the tube yourself and send it to the
lab.
D. Send the tube to the lab and call the provider to explain the
discrepancy.
Correct answer: B
Rationale — Correct (B): Proper patient identification at
bedside is required; specimen must be rejected and recollected
after positive patient identification to prevent misdiagnosis and
diagnostic errors.
Rationale — Incorrect:
A. Accepting is unsafe — name alone may not be unique.
C. Altering labels breaches protocol and risks wrong-patient
errors.
D. Sending mislabeled specimen perpetuates potential harm.
Teaching point: Always verify patient identity before labeling;
reject and recollect if discrepant.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2024). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.