LABORATORY AND DIAGNOSTIC TESTS.
11TH EDITION
• AUTHOR(S)FRANCES FISCHBACH;
MARGARET FISCHBACH; KATE STOUT
TESTBANKS
1
Reference
Ch. 1 — Diagnostic Testing
Stem
A 68-year-old patient is scheduled for a fasting lipid panel at
0800. At 0700 the nurse records that the patient ate breakfast
at 0630. The laboratory calls to ask whether the test should
proceed. Which action should the nurse take?
A. Proceed with the test and document the nonfasting state.
B. Cancel the test and schedule it for the next available morning
without further action.
,C. Proceed but add a note requesting that the lab multiply LDL
by 1.2 to adjust for nonfasting.
D. Draw the specimen now and advise the provider to interpret
results as fasting if they fall in normal range.
Correct answer
A
Rationale — Correct (A)
Fasting status is a preanalytic variable that affects many
chemistry tests; if the patient was not fasting, the nurse should
proceed only after confirming with the provider and document
the nonfasting state so results are interpreted appropriately and
repeated later if needed. Chapter 1 emphasizes documenting
pretest conditions and communicating deviations.
Rationale — Incorrect
B. Cancelling without provider notification may delay care and
ignores immediate documentation/communication
responsibilities.
C. Adjusting values mathematically is not an accepted nursing
action and risks invalid interpretation.
D. Assuming normal-range results are fasting misleads
clinicians; documentation of nonfasting is required.
Teaching point
Always document and communicate pretest deviations (fasting,
meds, activity).
,Citation
Fischbach, F., Fischbach, M., & Stout, K. (2024). A Manual of
Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
2
Reference
Ch. 1 — Diagnostic Testing
Stem
A nurse draws a stat chemistry specimen and notices the blood
tube appears pinkish and the serum sample later shows red
discoloration. The provider receives a potassium result that is
unexpectedly high. Which interpretation/action best reflects
nursing responsibility?
A. Assume the patient is hyperkalemic and arrange immediate
cardiology consult.
B. Document sample hemolysis, notify the lab, and request
repeat sampling before acting on potassium.
C. Discard the result and report instrumentation error to
biomedical engineering.
D. Give IV calcium to stabilize myocardium based on the single
elevated potassium value.
Correct answer
B
Rationale — Correct (B)
Hemolysis can artificially raise results (notably potassium) due
, to released intracellular contents; Chapter 1 highlights
preanalytic specimen integrity and that nurses should
document hemolysis, notify the lab, and obtain a repeat
specimen before initiating invasive treatment.
Rationale — Incorrect
A. Acting on a possibly hemolyzed result risks unnecessary
interventions.
C. Assuming instrumentation error is premature; hemolysis is a
common preanalytic cause.
D. IV calcium is indicated for true severe hyperkalemia with ECG
changes — not on a single suspicious value.
Teaching point
Suspect hemolysis when serum/plasma is red; repeat specimen
before definitive treatment.
Citation
Fischbach, F., Fischbach, M., & Stout, K. (2024). A Manual of
Laboratory and Diagnostic Tests (11th ed.). Ch. 1.
3
Reference
Ch. 1 — Diagnostic Testing
Stem
A nurse is preparing a urine culture for transport. Which
preanalytic action most reduces false-negative culture results?