Question 1 - What are Westgard Rules, Explain individual Rules?
Answer - Westgard Rules are QC rules to help analyze whether or not an
analytical run is in-control or out-of-control. It uses a combination of decision
criteria, usually 5 different control rules to judge the acceptability of an
analytical run. Westgard Rules are generally used with 2 measurements per run,
which means they are appropriate when two different control materials are
measured, which is the case in many biochemistry parameters.
For hematology, coagulations, and immunoassays applications some alternate
control rules are more suitable when three control materials are analyzed.
Explanation of Individual Rules
12s
One control measurement exceeding 2 standard deviations of control limits
either above or below the mean.
This rule is used a warning rule to trigger careful inspection of the control data.
13s
This rule is commonly used with a Levey-Jennings chart when the control limits
are set as the mean +3 standard deviations of control limits. A run is rejected
when a single control measurement exceeds the mean +3 control limits.
22s
The control run is rejected with 2 consecutive control measurements 2
standard deviations of control limits on the same side of mean with this rule.
R4s
This rule rejects a run if two control measurements in a group exceed the
mean with a 4 standard deviation difference between the 2 controls
41s
This rule rejects a run with the 4th consecutive control measurement
exceeding 1 standard deviation on the same side of the mean.
10x
This rule rejects a control run when there are 10 consecutive controls on the
same side of the mean.
Question 2 - How to perform multirule QC?
Answer - To perform multirule QC collect your control measurements in the
same way as you would for a regular Levey-Jennings control chart; establish
means and standard deviations for the control materials; then create a Levey-
Jennings chart with the mean +3, +2, and +1 standard deviations. The only
difference is the interpretation of the data.
The 12s rule is used as a warning to trigger application of the other rules. Any
time a single measurement exceeds a 2 standard deviation control limit, you
respond by inspecting the control data using the other rules. This doesn’t mean
stop, it just means to look carefully at the data before proceeding.
By using the following diagram, one should be able to decide what if any action
is required.
Control Data
12s
In-control
Report Results
13s 22s R4s 41s 10x
Out-of-control, Reject analytical run
No
yes yes yes yes yes
Yes
no no no no
no
Question 3 – What is total quality management in the laboratory
practices? What are it’s benefits?
Answer –
TQM means that the organization culture supports the constant patient
satisfaction through an integrated system of tools, techniques and
training.
It involves the continuous improvement of organization processes,
resulting in high quality products and services. Hence, TQM is “a
continuous, customer centred, employee driven improvement.”
“Quality is never an accident; it is always the
result of high intention, sincere effort, intelligent activities through which
the need and expectations of the customers are satisfied in most efficient
and cost-effective manner by maximizing the potential of all employers in
a continuing drive for improvement.
TQM essentially generates reliability and efficiency, profits by increasing
revenues also increase profit by cutting costs. For successful
implementation of TQM organizing must concentrate on ethics, integrity,
trust, training, teamwork, leadership, recognition and communication.
TQM in pathological practices comprises quality laboratory process,
quality control, quality assessment, quality improvement, quality
planning and quality goals.
TQM benefits are as:
Ensure quality in overall process. Curtail costs. Encourages active
and effective leadership and involvement by top management. Involves
and empowers staff. Attempting to solve problems by band aid fixes for
individual mistakes as they occur drastically reduced. Reduces errors by
doing thing right and ensures consistency. Staff will have greater
confidence that that the system will catch mistakes before the patient
report. All operations are transparent to both staff and clients and staff
will clearly understand their responsibility Improves consistency within
and between laboratories.
Total Quality Management of the Clinical Laboratory –
The principles and concepts of TQM have been formalized into a quality
management process. The traditional framework for managing quality in
a healthcare laboratory has emphasized the establishment of quality
laboratory processes (QLPs), QC, and quality assessment (QA). A QLP
includes analytical processes and the general policies, practices, and
procedures that define how work is done. QC emphasizes statistical
control procedures but also includes nonstatistical check procedures,
such as linearity checks, reagent and standard checks, and temperature
monitors. QA, as currently applied, is primarily concerned with broader
measures and monitors of laboratory performance, such as (1)
turnaround time, (2) specimen identification, (3) patient identification,
and (4) test utility. Quality “assessment” is the proper name for these
activities rather than quality “assurance.” Measuring performance does
not by itself improve performance and often does not detect problems in
time to prevent negative outcomes. Quality assurance requires that
causes of problems be identified through QI and eliminated through
quality planning (QP), or that QC be able to detect problems early enough
to prevent their consequences.
Question 4 – What is EQAS? How to interpret SDI?
Answer - External quality control or external assessment scheme (EQAS) or
proficiency testing program refers to the process of controlling the accuracy of
an analytical method by interlaboratory comparisons.
Its basic idea can be synopsized in the following steps:
1. The EQAS coordinator prepares and sends to the participants of the scheme
one or two samples from the same pool.
2. The samples are assayed by the laboratories using the same equipment and
reagents as they do in routine for the patients’ determinations.
3. The EQAS coordinator gathers all the results and it groups them (peer groups)
according the laboratories analytical methods, analyzers or any other criteria.
4. The EQAS coordinator calculates the target value (consensus mean) and its
total variation (expressed as standard deviation) of the laboratories results.
5. If any of the laboratories has values outside of the control limits (target value
± allowable variation) then this laboratory is considered “out of control”.
6. The “out of control” laboratories have to correct their analytical procedures.
“Standard Deviation Index” (SDI). SDI shows the distance of the laboratory
results from the consensus mean. It quantifies the inaccuracy of the analytical
method. It is similar to Z-score and it is calculated by the formula:
SDI = Laboratory mean – Peer group mean / Peer group SD
Interpretation of SDI –
The Four rules are usually employed for SDI evaluation:
1. 2/51SDI. Two from five successive control limits exceed 1 SDI. It is a warning
rule.
2. X1.5 SDI . The mean value of five SDI values exceeds the limits ±1.5 SDI. It
reveals a
lasting systematic error.
3. 13SDI. One value exceeds the limits ±3 SDI.
4. R4SDI. The range (R) between the lower and higher SDI values is over ±4 SDI.
Question 5 – How to manage blood spill in the laboratory?
Answer - BLOOD SPILLS shall be managed by following steps.
1. General Information
a. Universal precautions must be observed all the time.
b. If an untrained person encounters a spill, he/she
should limit access to the area and immediately call the
person assigned to this duty.
c. Only disposable towels should be used to avoid the
difficulties involved in laundering.
d. If a spill involves broken glassware, the glass should
never be picked up directly with the hands. It must be
cleaned up using mechanical means, such as a brush and
dustpan, tongs, or forceps.
2. Personal Protective Equipment
a. Persons who clean blood spills should wear disposable
gloves of sufficient strength so they will not tear during
cleaning activities. If the gloves develop holes, tears, or
splits, remove them, wash hands immediately, and put on
fresh gloves. Remove gloves one at a time by grasping the
wrist opening and pulling toward the fingers so that the
gloves come off as inside out. Double-bag gloves with other
contaminated biomedical waste (such as towels).
b. If enough blood has been spilled to expect splashing
during cleaning, call HAZMAT TEAM. Additional protective
equipment may be required.
3. Disinfectant
All spills must be disinfected with 1% sodium
hypochlorite solution, allowing a contact period of at least
15-20 minutes.
4. Cleaning Blood Spills on Hard Surfaces
a. Isolate the area, if possible.
b. Wear gloves and other protective apparel as needed.
c. Put towels/ news paper/ cotton cloth over the spill to
absorb the liquid.
d. The area should then be decontaminated with 1%
sodium hypochlorite allowing a contact period of at least 15-
20 minutes
f. All contaminated cloth/ news paper and gloves should
be double-bagged for disposal and labeled with the
biohazard symbol.
MCQs –
Q. 1 - All are true about De Ritis ratio except:
A. Ratio > 5 Indicates extrahepatic causes
B. alcoholic liver disease, the AST:ALT ratio is >1
C. scores >2 more suggestive of NAFLD/NASH.
D. muscle inflammation due to dermatomyositis may cause AST>ALT
Q. 2 - Match the right LDH Isoenzyme and its origin:
1. LDH1 a. Liver
2. LDH2 b. RBC
3. LDH3 c. Brain
4. LDH4 d. Heart
5. LDH5 e. Kidney
A. 1.d 2.b 3.a 4.c 5.e
B. 1.a 2.d 3.b 4.c 5.e
C. 1.d 2.b 3.c 4.e 5.a
D. 1.a 2.b 3.c 4.e 5.d
Q. 3 - Glucose transporter present in liver
A. GLUT 2 : Insulin Dependant, High Km, Low Affinity
B. GLUT 2 : Insulin Inependant, High Km, Low Affinity
C. GLUT 5 : Insulin Inependant, High Km, Low Affinity
D. GLUT 4 : Insulin Dependant, Low Km, High Affinity
Q. 4 - All are true about delta bilirubin except :
A. Delta-bilirubin is a bilirubin covalently bound with albumin
B. nontoxic and excreted neither in urine nor in bile
C. Calculated direct bilirubin results include the delta bilirubin fraction
D. Half-life of Delta bilirubin is 12-24 hours
Q. 5 - Gilbert syndrome is caused due to genetic variant in gene:
A. UGT1A1
B. UGT5A2
C. UGT2A2
D. UGT1A5
Q.6 – ALT becomes very specific to liver pathology when level crosses –
A. >100
B. >200
C. > 400
D. > 500
Q.7 - Bright liver syndrome (bright liver on ultrasound suggestive of fatty liver)
with raised ALT is suggestive of –
A. Metabolic Syndrome
B. Viral Hepatitis
C. Liver cirrhosis
D. Cholestasis
Q. 8 – Ceruloplasmin is increased in all except –
A. Sepsis
B. Rheumatoid Arthritis
C. Pregnancy
D. Wilson Disease
Answer Key -
1. C
2. C
3. B
4. D
5. A
6. D
7. A
8. D