FISCHBACH'S A MANUAL OF
LABORATORY AND DIAGNOSTIC TESTS.
11TH EDITION
• AUTHOR(S)FRANCES FISCHBACH;
MARGARET FISCHBACH; KATE STOUT
TESTBANKS
Ch. 1 — Diagnostic Testing
Stem: A patient in the medical-surgical unit is scheduled for a
fasting lipid panel at 0800. The patient ate a full breakfast at
0700. The nurse documents the event and sends the specimen
as scheduled. Which is the best nursing action?
A. Accept the specimen and document “non-fasting” — results
may be interpreted with notation.
B. Cancel the test and do not inform the provider; reorder
another fasting specimen the next day.
C. Proceed without documenting the breakfast; do not inform
provider to avoid delay.
,D. Immediately give insulin to correct postprandial effects and
send the specimen.
Correct answer: A
Rationale — Correct (A): Documenting that the specimen was
collected in a non-fasting state and sending it allows laboratory
personnel and the provider to interpret results with the known
preanalytic interference. Chapter 1 emphasizes that pretest
patient preparation (e.g., fasting) must be recorded when it is
not followed so clinical interpretation accounts for the
deviation. This action preserves patient safety and maintains
accurate clinical records.
Rationale — Incorrect:
B. Canceling without informing the provider removes useful
clinical information and delays care; the provider should be
notified to decide if results are acceptable.
C. Failing to document is a preanalytic error that may lead to
misinterpretation and inappropriate management.
D. Giving insulin for a routine postprandial state is inappropriate
and unsafe; medication decisions require provider orders and
clinical indication.
Teaching point: Always document and communicate deviations
from required patient preparation.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2021). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
,Ch. 1 — Diagnostic Testing
Stem: A STAT chemistry panel returns with a comment that the
sample is “hemolyzed.” The potassium result is markedly
elevated compared with the previous day’s value. What is the
nurse’s best next step?
A. Administer potassium-lowering therapy immediately based
on the elevated value.
B. Accept the result and chart it without action; hemolysis
comments are optional.
C. Notify the provider and arrange for a repeat specimen drawn
with careful technique.
D. Discard the elevated result and use the prior day’s result for
current clinical decisions.
Correct answer: C
Rationale — Correct (C): Hemolysis releases intracellular
potassium and other analytes, producing falsely elevated
results. Chapter 1 highlights preanalytic causes such as
hemolysis and directs staff to recognize flagged specimens and
obtain repeat samples with corrected collection technique.
Notification ensures safe, timely reassessment.
Rationale — Incorrect:
A. Treating on a hemolyzed, potentially spurious value risks
inappropriate therapy.
B. Ignoring the hemolysis comment is a preanalytic error that
can cause harm.
, D. Relying on stale results is unsafe; up-to-date, valid data are
required to guide immediate care.
Teaching point: Hemolyzed specimens can cause
pseudoelevations (e.g., potassium); repeat collection is
required.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2021). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
Ch. 1 — Diagnostic Testing
Stem: A complete blood count (CBC) returns with an
unexpected platelet count of 8,000/µL but the patient has no
bleeding and the phlebotomist reported difficulty mixing the
EDTA tube. Which interpretation and nursing action are most
appropriate?
A. Treat immediately for severe thrombocytopenia without
repeat testing.
B. Suspect in-tube clotting or processing error; notify the lab
and arrange a redraw with proper mixing.
C. Document the value and wait 24 hours before any action.
D. Assume the patient’s platelet count is normal and ignore the
result.
Correct answer: B
Rationale — Correct (B): Inadequate mixing of EDTA tubes or
clots can artifactually lower reported platelet counts. Chapter 1
emphasizes that preanalytic collection technique (tube
LABORATORY AND DIAGNOSTIC TESTS.
11TH EDITION
• AUTHOR(S)FRANCES FISCHBACH;
MARGARET FISCHBACH; KATE STOUT
TESTBANKS
Ch. 1 — Diagnostic Testing
Stem: A patient in the medical-surgical unit is scheduled for a
fasting lipid panel at 0800. The patient ate a full breakfast at
0700. The nurse documents the event and sends the specimen
as scheduled. Which is the best nursing action?
A. Accept the specimen and document “non-fasting” — results
may be interpreted with notation.
B. Cancel the test and do not inform the provider; reorder
another fasting specimen the next day.
C. Proceed without documenting the breakfast; do not inform
provider to avoid delay.
,D. Immediately give insulin to correct postprandial effects and
send the specimen.
Correct answer: A
Rationale — Correct (A): Documenting that the specimen was
collected in a non-fasting state and sending it allows laboratory
personnel and the provider to interpret results with the known
preanalytic interference. Chapter 1 emphasizes that pretest
patient preparation (e.g., fasting) must be recorded when it is
not followed so clinical interpretation accounts for the
deviation. This action preserves patient safety and maintains
accurate clinical records.
Rationale — Incorrect:
B. Canceling without informing the provider removes useful
clinical information and delays care; the provider should be
notified to decide if results are acceptable.
C. Failing to document is a preanalytic error that may lead to
misinterpretation and inappropriate management.
D. Giving insulin for a routine postprandial state is inappropriate
and unsafe; medication decisions require provider orders and
clinical indication.
Teaching point: Always document and communicate deviations
from required patient preparation.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2021). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
,Ch. 1 — Diagnostic Testing
Stem: A STAT chemistry panel returns with a comment that the
sample is “hemolyzed.” The potassium result is markedly
elevated compared with the previous day’s value. What is the
nurse’s best next step?
A. Administer potassium-lowering therapy immediately based
on the elevated value.
B. Accept the result and chart it without action; hemolysis
comments are optional.
C. Notify the provider and arrange for a repeat specimen drawn
with careful technique.
D. Discard the elevated result and use the prior day’s result for
current clinical decisions.
Correct answer: C
Rationale — Correct (C): Hemolysis releases intracellular
potassium and other analytes, producing falsely elevated
results. Chapter 1 highlights preanalytic causes such as
hemolysis and directs staff to recognize flagged specimens and
obtain repeat samples with corrected collection technique.
Notification ensures safe, timely reassessment.
Rationale — Incorrect:
A. Treating on a hemolyzed, potentially spurious value risks
inappropriate therapy.
B. Ignoring the hemolysis comment is a preanalytic error that
can cause harm.
, D. Relying on stale results is unsafe; up-to-date, valid data are
required to guide immediate care.
Teaching point: Hemolyzed specimens can cause
pseudoelevations (e.g., potassium); repeat collection is
required.
Citation: Fischbach, F., Fischbach, M., & Stout, K. (2021). A
Manual of Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
Ch. 1 — Diagnostic Testing
Stem: A complete blood count (CBC) returns with an
unexpected platelet count of 8,000/µL but the patient has no
bleeding and the phlebotomist reported difficulty mixing the
EDTA tube. Which interpretation and nursing action are most
appropriate?
A. Treat immediately for severe thrombocytopenia without
repeat testing.
B. Suspect in-tube clotting or processing error; notify the lab
and arrange a redraw with proper mixing.
C. Document the value and wait 24 hours before any action.
D. Assume the patient’s platelet count is normal and ignore the
result.
Correct answer: B
Rationale — Correct (B): Inadequate mixing of EDTA tubes or
clots can artifactually lower reported platelet counts. Chapter 1
emphasizes that preanalytic collection technique (tube
