BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1)
Reference: Ch. 1 — Quality Assessment — Quality indicators
and error rates
Stem: A busy urinalysis laboratory tracks specimen labeling
errors as a quality indicator. Over a month the lab processed
6,000 urine specimens and recorded 18 labeling errors. The
lab’s goal is ≤0.2% labeling errors. As the MLS assigned to QA,
what is the best interpretation and next step?
,A. The error rate is acceptable; continue routine monitoring.
B. The error rate (0.3%) exceeds the goal; perform a root-cause
analysis and implement corrective actions.
C. The error rate is within expected random variation; increase
sample throughput to dilute the rate.
D. Discard the data as outliers and recalculate using only the
last two weeks’ records.
Correct answer: B
Rationale — Correct (B): The calculated error rate = 18/6000 =
0.003 = 0.3%, which exceeds the lab target of ≤0.2%. The
appropriate QA response is to perform a root-cause analysis to
identify contributing factors (pre-analytical issues such as
mislabeling at collection, ambiguous specimen IDs, technician
workflow), implement corrective actions (retraining, label
redesign, process change), and monitor for improvement. This
follows standard QA practice for quality indicators.
Rationale — Incorrect:
A. Incorrect — 0.3% exceeds the stated goal; passive monitoring
is insufficient.
C. Incorrect — Increasing throughput does not address
underlying errors and may worsen them.
D. Incorrect — Selective data exclusion is inappropriate unless
justified; the full dataset should be analyzed.
Teaching point: Exceeding quality indicator goals requires root-
cause analysis and corrective action.
,Citation: Brunzel, N. A. (2023). Fundamentals of Urine and Body
Fluid Analysis (5th ed.). Ch. 1.
2)
Reference: Ch. 1 — Quality Assessment — Internal QC and
control materials
Stem: An automated urine chemistry analyzer shows a daily
Levey-Jennings plot for the creatinine control where the last
two daily control points for Level 2 are slightly below the mean
by 1.9 SD and 2.1 SD respectively. No patient results are flagged
by the instrument. What is the best MLS action?
A. Release patient results; the shift is small and within
acceptable limits.
B. Hold patient results, investigate instrument maintenance logs
and reagent lot changes, and run duplicate controls.
C. Adjust the instrument mean to include the new control
values and release patient results.
D. Replace the control material immediately with a new lot and
rerun patient samples.
Correct answer: B
Rationale — Correct (B): Two consecutive control points
approaching and crossing the 2 SD boundary suggest a possible
systematic shift or emerging bias. Best practice is to hold results
while investigating possible causes (reagent lot, calibration,
environmental factors, instrument maintenance), rerun controls
, (including duplicates), and perform troubleshooting steps
before releasing patient results. This aligns with quality control
rules to detect trends and shifts.
Rationale — Incorrect:
A. Incorrect — Releasing without investigation risks reporting
biased patient results.
C. Incorrect — Retrospective adjustment of instrument mean is
inappropriate without full evaluation and documented re-
calibration.
D. Partially incorrect — Replacing control lot may be
reasonable, but immediate replacement without investigation
and verification is premature.
Teaching point: Two control values near/over 2 SD warrant
investigation before reporting patient results.
Citation: Brunzel, N. A. (2023). Fundamentals of Urine and Body
Fluid Analysis (5th ed.). Ch. 1.
3)
Reference: Ch. 1 — Quality Assessment — Proficiency testing
(external quality assessment)
Stem: Your lab receives a proficiency testing (PT) survey for
urine microscopy. Your result differs substantially from the
consensus and the PT provider flags it as “unsatisfactory.” The
MLS review finds microscopy slides were prepared from a
residual specimen that sat at room temperature for 24 hours