BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1️⃣
Reference: Ch. 1 — Quality Assessment — Quality indicators
and control materials
Stem: A urinalysis lab runs daily positive and negative controls
for dipstick chemistry on a new lot of reagent strips. The
positive control reads within target but the negative control
shows a faint trace of protein when previous lots were
consistently negative. The technologist must decide the next
step. Which action is most appropriate?
,A. Release patient results; a faint trace in negative control is
clinically insignificant.
B. Quarantine the current lot and repeat both controls in
duplicate; investigate pre-analytical contamination.
C. Adjust the negative-control target range upward to include
the faint trace and document the change.
D. Discard the control material and order a new control bottle
without further investigation.
Correct answer: B
Rationale — Correct (B): Repeat controls in duplicate and
quarantine the lot to determine whether the shift is
reproducible or due to contamination. This evaluates control
performance, distinguishes random contamination from lot-
related shift, and initiates appropriate QA actions.
Rationale — Incorrect:
A: Releases patient results despite control shift — violates QA.
C: Changing target range without investigation masks a
potential analytical problem.
D: Discarding control without repeating/assessing wastes
resources and misses root cause.
Teaching point: Reproduce control discrepancies and
quarantine suspect reagent lots before releasing patient results.
Citation: Brunzel, N. A. (2023). Fundamentals of Urine and Body
Fluid Analysis (5th ed.). Ch. 1.
,2️⃣
Reference: Ch. 1 — Quality Assessment — Levey-Jennings and
trend detection
Stem: A Levey-Jennings chart for urine specific gravity control
shows five consecutive points that are progressively higher but
still within ±2 SD. What is the best laboratory response?
A. Consider the run acceptable; all points are within ±2 SD.
B. Investigate for systematic error (calibration drift or
instrument bias) and perform corrective maintenance.
C. Lower the control mean to bring recent points within range.
D. Replace control material and ignore the trend if new controls
read within range.
Correct answer: B
Rationale — Correct (B): A consistent upward trend, even
within ±2 SD, indicates systematic error (drift) and requires
investigation (calibration check, instrument maintenance,
reagent stability). This addresses analytical bias before patient
impact.
Rationale — Incorrect:
A: Ignores trend detection rules; trends can precede out-of-
control events.
C: Arbitrary changing of mean masks problems and breaches
QA.
D: Replacing controls without root-cause analysis risks repeating
the error.
, Teaching point: Trends within control limits can signal
systematic error and require investigation.
Citation: Brunzel, N. A. (2023). Fundamentals of Urine and Body
Fluid Analysis (5th ed.). Ch. 1.
3️⃣
Reference: Ch. 1 — Quality Assessment — Westgard rules
application
Stem: In a microscopy QC program, a platelet count equivalent
control triggers a 1_3s Westgard violation on a chemistry
analyzer used adjunctly for creatinine on urine. The lab runs a
second control that is within range. Which interpretation/action
is best?
A. Treat the initial 1_3s as a random error; accept patient
results because the repeat control passed.
B. Lock the analyzer and remove it from service because any
1_3s violation requires instrument retirement.
C. Perform instrument troubleshooting, review recent
maintenance and reagent lots, then run patient testing only
after controls are consistently acceptable.
D. Ignore since microscopy QC is separate from chemistry
controls.
Correct answer: C
Rationale — Correct (C): A single 1_3s may be a random error,
but best practice is to troubleshoot, review recent changes, and