BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1
Reference
Ch. 1 — Quality Assessment — Internal quality control and
control material limitations
Stem (MLS level)
A chemistry automation line reports consistent reagent strip
results but technicians notice that sediment components (RBCs,
casts) are not assessed by the daily QC material. Your lab
,occasionally exchanges completed patient urine specimens with
a nearby outpatient clinic for cross-checking sediment
competency. During one exchange, the receiving lab reports
markedly different microscopic RBC counts on the same
specimen. Which is the best laboratory action to investigate and
resolve the discrepancy?
A. Repeat the microscopy at both sites using fresh centrifuged
aliquots and compare preparation, staining, and counting
methods.
B. Discard the exchanged specimen as transport-compromised
and rely only on reagent strip QC for patient reporting.
C. Accept the outpatient clinic’s results because instrument QC
passed and only pre-analytical error at sending site is possible.
D. Replace the control material with a liquid control that
contains fixed sediment so future exchanges are unnecessary.
Correct answer
A
Rationales
Correct (A): Repeating microscopy at both sites using identical
centrifugation, aliquot, and slide-preparation protocols allows
comparison of pre-analytical and analytical variables (centrifuge
speed/time, sediment resuspension, staining, grid/counting
method). This approach isolates whether differences are due to
technique, operator competency, or specimen instability — a
necessary root-cause step before corrective action.
Incorrect (B): Discarding the specimen and relying only on
,reagent strip QC ignores that strips do not evaluate sediment
morphology/counts; it fails to investigate the discrepancy and
risks diagnostic error.
Incorrect (C): Accepting the other lab’s result because
instrument QC passed is circular reasoning; instrument
chemical QC does not control for microscopic technique or
specimen handling.
Incorrect (D): Replacing control with fixed-sediment liquid may
help QC but does not address immediate interlaboratory
disagreement or verify competency; it’s a future-oriented
mitigation, not an investigation.
Teaching point
Repeat testing with standardized preparation to isolate pre-
analytical vs analytical causes.
Citation
Brunzel, N. A. (2022). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
2
Reference
Ch. 1 — Quality Assessment — External quality assessment /
proficiency testing (PT)
Stem (MLS level)
Your laboratory receives a proficiency testing (PT) specimen
with an abnormal dipstick protein result that conflicts with the
, lab’s routine patient protein results. The PT provider’s
instructions state the specimen requires refrigeration upon
receipt. Lab staff left the PT panel at room temperature
overnight before testing. Which interpretive action best adheres
to QA principles?
A. Report the PT result as obtained and annotate the PT
submission with pre-analytical deviation.
B. Reject the PT specimen, document the temperature
deviation, and request a reschedule from the PT provider.
C. Heat the specimen to 37°C to normalize proteins, then run
and submit results.
D. Run the PT specimen and submit the result without
comment to avoid audit flags.
Correct answer
B
Rationales
Correct (B): PT specimens are quality assessment challenges;
pre-analytical deviations (improper storage) invalidate the
challenge. The correct QA action is to document the deviation,
reject the compromised specimen per policy, and request a
replacement/reschedule to preserve PT integrity.
Incorrect (A): Reporting the invalid PT result, even with
annotation, compromises the lab’s PT performance record and
fails to follow PT provider/CLIA requirements.
Incorrect (C): Heat treatment cannot reliably reverse all
temperature-induced analyte changes and would falsify