BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1)
Reference: Ch. 1 — Quality Assessment and Safety — Quality
control failure investigation
Stem: A technologist running daily urine dipstick QC (two levels)
notes that the low-level control’s nitrite result is weakly positive
while all other analytes and the high-level control are within
expected limits. The reagent strip lot and instrument passed
calibration last week. Which is the most appropriate next step?
,A. Report run as valid because only one analyte at low-level
control is off.
B. Repeat the low-level control in duplicate and inspect strip
storage and expiry.
C. Replace the analyzer’s light source immediately and re-run
both controls.
D. Discard the low-level control bottle and continue testing
patient specimens with caution.
Correct answer: B
Rationale — Correct (B): Repeat the low-level control to
confirm reproducibility and check pre-analytical factors
(storage, expiration, lot integrity). Many single-analyte QC shifts
arise from strip handling, expired lots, or QC prep errors;
duplicating helps determine random vs. systematic error before
corrective actions that affect the analyzer.
Rationale — Incorrect:
A: Single-analyte failure at low-level control invalidates that
analyte’s run; reporting without investigation risks false
positives.
C: Immediate replacement of the light source is excessive
without evidence implicating the optical system.
D: Discarding QC without investigation loses diagnostic
information and violates QC documentation requirements.
Teaching point: Always repeat QC failures and assess pre-
analytical variables before instrument interventions.
,Citation: Brunzel, N. A. (2023). Fundamentals of Urine and Body
Fluid Analysis (5th ed.). Ch. 1.
2)
Reference: Ch. 1 — Quality Assessment and Safety — Westgard
rules application
Stem: During a month of day-shift urinalysis QC, the lab’s Levey-
Jennings chart for specific gravity shows one point beyond ±2
SD (but within ±3 SD) at low-level control. Two days later a
single point exceeds +3 SD at the same control. Which
interpretation and action are most appropriate?
A. Apply the 12s Westgard rule and accept the run since a single
2 SD exceedance is allowed.
B. Treat the +3 SD point as an unacceptable systematic error,
stop testing, and initiate corrective action.
C. Ignore both points because specific gravity by refractometer
is more reliable than dipstick QC.
D. Recalibrate the refractometer and continue testing without
re-running controls.
Correct answer: B
Rationale — Correct (B): A measurement beyond ±3 SD
indicates a likely systematic error per Westgard principles and
requires halting patient testing, investigating sources (reagents,
instrument, calibration), and repeating QC before resuming.
Document findings and corrective actions.
Rationale — Incorrect:
, A: The 12s rule (single measurement >±2 SD) is a warning; a
subsequent >±3 SD indicates a reject condition and requires
action.
C: Dismissing dipstick QC without verification is unsafe;
refractometer comparison can be part of investigation but not
an excuse to ignore QC.
D: Recalibration may be necessary but must follow an
investigation and re-running controls, not immediate
continuation.
Teaching point: A single QC >±3 SD mandates stopping testing
and investigating systematic error.
Citation: Brunzel, N. A. (2023). Fundamentals of Urine and Body
Fluid Analysis (5th ed.). Ch. 1.
3)
Reference: Ch. 1 — Quality Assessment and Safety —
Proficiency testing (PT) discrepancy
Stem: Your lab receives PT samples for urinalysis microscopy.
The PT provider’s result for RBC count is 0–2/HPF. Your lab’s
submitted result is 5–10/HPF. The lab follows SOPs and
instrument maintenance logs look current. What is the most
defensible next step in PT discrepancy handling?
A. Submit a revised PT result after re-running the sample to
match the provider.
B. Document the discrepancy, perform root-cause analysis
including slide review and technologist competency, and report