LABORATORY AND DIAGNOSTIC TESTS.
11TH EDITION
• AUTHOR(S)FRANCES FISCHBACH;
MARGARET FISCHBACH; KATE STOUT
TESTBANKS
Q1
Reference: Ch. 1 — Diagnostic Testing
Stem: A 62-year-old patient is to have a fasting lipid panel for
cardiovascular risk assessment. The nurse notes the patient
reports eating half an hour earlier. The patient refuses to delay
the test. Which is the most appropriate nursing action?
A. Proceed with specimen collection and document nonfasting
status.
B. Cancel the test and reschedule for a different day without
notifying the provider.
,C. Proceed and label the specimen "fasting" because the
provider ordered a fasting panel.
D. Draw an extra specimen now and one after an overnight fast
without informing the laboratory.
Correct answer: A
Rationale — Correct (A): Proceeding with collection while
documenting the nonfasting status preserves patient care
continuity and provides the laboratory and ordering clinician
with accurate context for interpretation. Fischbach emphasizes
proper documentation of preanalytic variables (e.g., fasting
status) to avoid misinterpretation. This action prevents
unnecessary delay while ensuring correct interpretation.
Rationale — Incorrect (B): Canceling and rescheduling without
provider notification may delay care and removes a potentially
useful nonfasting result; communication with the team is
required.
Rationale — Incorrect (C): Mislabeling the specimen risks
erroneous interpretation and may lead to inappropriate
treatment decisions.
Rationale — Incorrect (D): Collecting extra specimens without
lab coordination can cause confusion, waste resources, and
violate specimen handling protocols.
Teaching point: Always document preanalytic variables (eg,
nonfasting) on the lab requisition.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2024). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
,Q2
Reference: Ch. 1 — Diagnostic Testing
Stem: A patient with suspected sepsis is started on antibiotics in
the ED. Blood cultures were ordered before antibiotic
administration, but nursing documents show an antibiotic dose
given 10 minutes prior to culture draw. What is the most
important interpretation and next action?
A. Recognize that prior antibiotics may reduce culture yield;
notify the provider and attempt to obtain additional cultures if
feasible.
B. Assume cultures will be positive regardless and do nothing
further.
C. Discard the drawn cultures because they are now invalid.
D. Wait 24 hours and then draw cultures to improve accuracy.
Correct answer: A
Rationale — Correct (A): Antibiotics given before blood culture
collection can decrease culture sensitivity and yield false-
negative results; Fischbach highlights timing as a critical
preanalytic variable. The nurse should notify the provider;
additional cultures prior to further antibiotics may be indicated
to improve diagnostic yield.
Rationale — Incorrect (B): Assuming positivity ignores the
decreased sensitivity caused by antibiotics and risks missed
diagnosis.
Rationale — Incorrect (C): Discarding specimens is
, inappropriate; labs may still process and report results, and
documentation of timing is essential.
Rationale — Incorrect (D): Waiting 24 hours may delay
diagnosis and treatment decisions; cultures should be obtained
ASAP before subsequent antibiotic doses if possible.
Teaching point: Obtain blood cultures before antibiotics
whenever possible; document timing precisely.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2024). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
Q3
Reference: Ch. 1 — Diagnostic Testing
Stem: A portable point-of-care (POC) glucose result from a
fingerstick reads 52 mg/dL in a symptomatic patient. The
central laboratory serum glucose drawn at the same time
returns 78 mg/dL. How should the nurse interpret and act on
these discrepant results?
A. Treat the patient for hypoglycemia immediately based on the
POC result and recheck.
B. Ignore the POC reading and only use the central lab value
because it is more accurate.
C. Report the discrepancy to lab services, treat the patient
according to clinical symptoms, and repeat confirmatory testing
per policy.
D. Assume the fingerstick technique was faulty and do nothing.