BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1)
Reference
Ch. 1 — Quality Assessment — Internal Quality Control (IQC)
Stem
A urine chemistry analyzer shows repeated low-specific-gravity
readings for the morning batch; the daily control material run 1
hour earlier was within acceptable limits. The technologist
notes that the reagent lot was recently changed and ambient
temperature in the instrument room has been 5°C lower than
,usual overnight. Which action best follows the IQC and quality-
assurance principles?
A. Report results and advise clinician about possible low SG due
to dehydration.
B. Re-run the control material and patient specimens after
warming reagents and instrument to recommended
temperature.
C. Replace the analyzer membrane and proceed without re-
running controls.
D. Apply a statistical correction factor to the patient SG results
based on previous month’s means.
Correct Answer
B
Rationale — Correct (3–4 sentences)
Re-running controls and patient specimens after ensuring
reagents and instrument are at validated operating temperature
addresses a likely pre-analytical/analytical cause. Quality-
assurance principles require confirmation that an
environmental change (temperature) affected results before
reporting. This step ensures that IQC remains valid for the
current run.
Rationale — Incorrect
A. (1–2 sentences) Reporting without verifying the analytical
integrity ignores possible instrument/reagent effects and
violates QA.
C. (1–2 sentences) Replacing hardware without confirming
,temperature effect is premature and wasteful; QC must be run
after maintenance.
D. (1–2 sentences) Applying ad hoc statistical corrections is
unacceptable; QC/verification procedures are required before
modifying results.
Teaching Point
Verify instrument/reagent conditions and re-run controls before
reporting questionable results.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
2)
Reference
Ch. 1 — Quality Assessment — Westgard Rules & Control
Interpretation
Stem
A laboratory uses two levels of urinalysis chemical QC. On
today’s Levey–Jennings chart, Level 1 control is at +3 SD and
Level 2 is at +1 SD. Which interpretation and action align with
established Westgard and QA protocols?
A. Accept the run since at least one control is within ±2 SD.
B. Reject the run and investigate for systematic error before
releasing patient results.
C. Release results with a comment noting increased variability.
, D. Dilute all patient specimens two-fold to bring analyte
concentrations into expected range.
Correct Answer
B
Rationale — Correct (3–4 sentences)
A control at +3 SD indicates a likely systematic error or shift; this
violates single-rule acceptability and requires run rejection.
Westgard rules dictate investigation (reagents, calibration,
instrument) and corrective action before patient reporting.
Rejecting the run preserves patient safety and QA integrity.
Rationale — Incorrect
A. (1–2 sentences) Single control within ±2 SD does not
compensate for another control at +3 SD; run should not be
accepted.
C. (1–2 sentences) Releasing with a comment bypasses
corrective action and may harm patients.
D. (1–2 sentences) Dilution of specimens without diagnosing
analytical failure is inappropriate and could introduce error.
Teaching Point
A ±3 SD control breach mandates run rejection and
investigation.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.