BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1
Reference
Ch. 1 — Quality Assessment and Safety — Quality assessment
programs
Stem (MLS-level)
A busy urinalysis lab recently introduced a new automated
urine chemistry analyzer. Over three months, internal QC shows
a small but consistent positive shift in creatinine and glucose
,compared with historical values; external proficiency testing
(PT) results remain acceptable. Technologists report no
instrument alarms and maintenance logs are current. What is
the best next step in quality assessment?
Options
A. Immediately remove the analyzer from service and send for
vendor repair.
B. Review recent lot numbers of reagent strips and perform a
lot-to-lot comparison with the previous reagent lot.
C. Ignore the shift since PT results are acceptable and continue
routine monitoring.
D. Retrain staff on specimen handling and recollect specimens
for comparison.
Correct Answer
B
Rationales
• Correct (B): A consistent small shift with acceptable PT
suggests an analytical bias probably related to reagents or
calibration—lot-to-lot reagent verification differentiates
reagent-related shifts from instrument failure. Lot-to-lot
comparison is an appropriate investigation step before
more disruptive actions.
• Incorrect (A): Removing the analyzer is premature; no
alarms or maintenance issues and acceptable PT suggest
instrument function is likely adequate.
, • Incorrect (C): PT being acceptable does not exclude
systematic bias; ignoring the shift risks reporting clinically
significant changes.
• Incorrect (D): Staff technique could cause variability but
the pattern (parallel shift in multiple analytes) and lack of
other indicators favor reagent or calibration issues over
operator error.
Teaching Point
Always verify new reagent lots when seeing a systematic
analytical shift.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
2
Reference
Ch. 1 — Quality Assessment and Safety — Quality control rules
and interpretation
Stem (MLS-level)
A Levey-Jennings plot for urine protein reagent strip QC shows
three consecutive daily control measurements trending upward
but still within ±2 SD. The technologist questions whether to
report patient results. Which interpretation/action best reflects
quality-assessment principles?
, Options
A. Patient results are reportable because control values are
within ±2 SD.
B. Implement a Westgard rule investigation because three
consecutive trending points may indicate an impending
systematic error.
C. Discard the three days of QC and repeat controls only when
the trend reverses.
D. Increase frequency of QC to hourly until values return to
baseline, but continue reporting.
Correct Answer
B
Rationales
• Correct (B): Trend of consecutive shifts, even within ±2 SD,
violates the concept of monitoring for trends; Westgard or
similar rules prompt investigation before bias reaches
unacceptable limits. Investigation can identify pre-
analytical or analytical causes.
• Incorrect (A): Numeric acceptance within ±2 SD doesn’t
preclude a meaningful trend; reporting without inquiry
risks false patient interpretation.
• Incorrect (C): Discarding data is improper; QC records must
be retained and investigated, not deleted.