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How to Buy
ESR Analyzers
st
EDITION
Your guide to gold standard Westergren
erythrocyte sedimentation rate analysis
2020
Cell Counting
How
to Buy ESR
Technology
Analyzers
An introduction to erythrocyte
sedimentation rate and its uses
The erythrocyte sedimentation rate (ESR) is
a simple and inexpensive clinical laboratory
test that detects increases in protein in the
blood and is used as a non-specific marker
of inflammation and infection.
Despite the introduction of alternative
methods for rapidly determining ESR,
the traditional Westergren method is still
considered the gold standard for testing. Both
the International Council for Standardization
in Haematology (ICSH) and the Clinical
& Laboratory Standards Institute (CLSI)
recommend this as the method of choice
and use it as the standard for comparison for
emerging techniques.
In this eBook, we will provide a
comprehensive overview of ESR analysis,
including why ESR remains a valuable clinical
tool, best practices for determining ESR
Contents
1. Why use ESR?
2. How to determine ESR
3. Key considerations
4. Meet the ESR experts
5. ESR and COVID-19 management
6. Summary & acknowledgments
7. Editor’s picks
using the Westergren method, and important
considerations for choosing your ESR analyzer.
Plus, hear from ESR experts and find out
how this tool is aiding the management of
COVID-19 in hospitals.
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How
to Buy ESR
Technology
Analyzers
1. Why use ESR?
ESR testing works by measuring the rate at
which red blood cells (RBCs or erythrocytes)
gradually aggregate and settle as a sediment
at the bottom of a vertical sample tube,
separating from the clear liquid plasma above.
The separation of RBCs and blood plasma is
influenced by the number of proteins that are
bound to the RBCs. In inflammation, proteins
such as acute reactive proteins bind to the
surfaces of RBCs, changing
their morphology and causing
them to aggregate and form
what is known as a rouleaux.
This rouleaux sinks much more
rapidly than RBCs in a normal
blood sample.
An ESR measurement is
expressed as millimeters
per hour (mm/hr), where the
amount of clear plasma at the
top of the sample tube
(in mm) is measured after a set
amount of time (traditionally
one hour). The higher the ESR value, the more
inflammation that is present in the body.
ESR varies by individual and can fluctuate
depending on normal considerations,
such as:
“
•D
rug use (oral contraceptives and
antibiotics can increase ESR; aspirin
and steroids can decrease ESR)
However, a very high ESR is associated
with infection and can also be elevated in
many inflammatory conditions, including
anemia, autoimmune diseases, muscular
and connective tissue disorders, some
cancers and tumors, renal
failure, and organ transplant
rejection. Some conditions
also lower the ESR, such as
heart failure and some liver
and kidney diseases.
The test is used to indirectly
detect both acute and chronic
inflammation, whether to
initiate a diagnosis, monitor
disease activity or discern
the response to treatments.
However, whilst ESR detects
inflammation, this test alone
does not provide information on where the
inflammation is in the body, nor what is
causing it. As a result, ESR is often the first
point of call for determining whether there
is a problem and is used in conjunction with
other tests. These could include cultures to
investigate bacterial infection; antinuclear
antibody (ANA) and rheumatoid factor (RF)
tests for suspected autoimmune diseases
such as rheumatoid arthritis; or serum
electrophoresis to investigate cancers such as
multiple myeloma and lymphoma.
The higher
the ESR value,
the more
inflammation
that is present
• Weight (elevated in obesity)
•G
ender (elevated for females, also during
pregnancy and menstruation)
“
• Age (moderately elevated in old age)
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How to Buy ESR Analyzers
2. How to determine ESR
The gold standard technique for ESR
determination is the Westergren
method. Despite the introduction of
new alternative techniques that promise
faster and more economical results,
systems based on Westergren remain the
method of choice among clinicians around
the world.
In a typical ESR workflow for manual systems:
•A
2ml whole blood sample is collected
from a patient
•T
his is transferred into a standardized
Westergren tube with a 200mm
calibrated scale
•T
he sample is accessioned, and the tube
barcode is scanned
•T
he sample is thoroughly mixed with
anticoagulant and diluted to 4:1
• The tube is placed in a vertical rack
•A
fter one hour, the distance between
the surface of the clear plasma and the
top of the RBC sediment is measured
in millimeters
a. Whole blood sample
b. Normal ESR after 60 minutes
c. Example of an elevated ESR after
60 minutes
There are several factors that must be
considered that could otherwise impact
the quality of results and potentially lead
to false reporting. For optimal performance,
a number of factors should be taken
into consideration when performing ESR
measurements and choosing the right ESR
analyzer for your lab.
Normal ESR values
•0
-22 mm/hr for men
•0
-29 mm/hr for women
•C
RP < 3 mg/L
•P
V 1.50-1.72 mPA
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3. Key considerations
“
value that can be measured is much lower.
The material and composition of the tubes
must also be considered. Plastic tubes
improve safety in the lab by promising no
exposure to glass sharps and potential
pathogens in case of breakage. However,
there is the additional consideration of
the plastics’ adhesive
properties and contained
plasticizers, which risk
affecting the sample.
Glass tubes address the
risk of contamination and
provide the additional
benefit of reusability,
promoting more
sustainable practices.
“
Sample quality
Quality control is an essential consideration
for any hematological test to ensure
confidence in the accuracy and precision of
results. To retain quality in blood samples,
ESR tests should be performed within four
hours of sample collection. This reduces
the risk of associated
crenation and sphering of
stagnated RBCs,
which would otherwise
interfere with normal
sedimentation rates.
The use of vacuum
tubes allows for
closed-tube testing
Tube type
Uniformity of tubes is
essential in ensuring
reliability in results. Tube length and diameter
must be kept constant throughout the lab.
It is recommended that tubes are at least
200mm and 2.55mm in diameter for manual
testing, but many automated analyzers use
tubes that are 8x120mm. Shorter tubes will
decrease the ESR as the maximum abnormal
Orientation
The orientation of the ESR tube can also
influence ESR, as tilting the tube causes
RBCs to aggregate along the lower side while
plasma rises along the upper side, causing the
appearance of a falsely raised or reduced ESR.
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How to Buy ESR Analyzers
Safety
Collecting hematological samples from
patients incurs the risk of exposure to
bloodborne pathogens. However, the use of
vacuum tubes allows for closed-tube testing.
This provides direct sample collection and
eliminates the need for sample transfer,
saving time and reducing the risk of exposure
to patient blood samples. The use of vacuum
tubes also requires less blood to be drawn
(1ml) and reduces the risk of air bubbles
in the sample, which can lead to a falsely
increased ESR.
Vacuum ESR tubes, such as those from ELITechGroup, allow for
closed-tube testing and can come prefilled with sodium citrate for
automatic sample dilution.
Anticoagulant and dilution
Anticoagulants, such as sodium citrate or
ethylenediaminetetraacetic acid (EDTA),
are added to blood samples prior to ESR
measurement to prevent coagulation and
preserve normal RBC morphology.
The Westergren method requires a 4:1
ratio of blood to anticoagulant. An excess of
anticoagulant will decrease the natural ESR,
and too little anticoagulant will cause your
blood sample to clot and increase the ESR.
Vacuum ESR tubes can come prefilled with an
anticoagulant, which allows for automatic and
controlled dilution of samples.
Liquid-based anticoagulants, such as
sodium citrate, can cause errors in dilution of
the blood sample if measured inaccurately,
consequently affecting the ESR rate. This has
led many clinicians to modify the Westergren
method and use solid-based EDTA instead.
Temperature
If uncontrolled, temperature will impact the
ESR. Increases in the temperature of the
sample will cause an increase in the ESR. As
a result, testing temperatures should be kept
constant, between 18°C and 25°C, and any
refrigerated samples should not be tested
until they have reached a standardized room
temperature once again.
Run time
By default, ESR testing by the Westergren
method takes 60 minutes. However, with the
introduction of automated instrumentation,
some analyzers allow for the extrapolation of
data from a 30-minute or even 15-minute test.
This allows for more rapid testing, along with
the assurance of accuracy and reliability.
Analyzer capacity
When choosing an ESR analyzer, an important
consideration is the expected frequency of
ESR testing and throughput required. This
will determine the number of tube positions
required in your analyzer.
Automation
Many of the above considerations can be
accounted for using automation. Many
automated ESR analyzers incorporate the
traditional gold standard Westergren method,
whilst making analysis safer and more
accurate than manual methods.
Automation can be used to control for
variables, such as temperature and tube
tilting, that may otherwise influence the
results from manual analysis. Automation
also allows for the integration of features
that help streamline a clinical laboratory
and optimize its workflows, including:
arcode scanning allows clinicians to keep
B
track of blood samples and patient results
more easily.
Integrated quality control capabilities
ensure accuracy and reliability in results,
whilst reducing analyzer downtime.
On-board mixers ensure samples are
well mixed, providing standardization
not easily achieved through manual
methods, as well as removing the
need for additional mixing equipment.
Alternative methods
The Wintrobe method is very similar to the
Westergren method, but the tubes used are
much shorter (100mm) and thinner. As a
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How to Buy ESR Analyzers
result, this method is less sensitive and is now
often used for demonstration purposes only.
Newer methods of analysis, such as
Test-1 and iSED analyzers, promise faster
results (20-second readouts) from much
lower volumes of blood. However, it takes
approximately ten minutes for RBCs to fall at
a steady rate, therefore tests that claim to
provide results before this physical process
is complete could lead to false negatives and
increase the risk of missed diagnosis.
There are also other tests that are used
as an initial indication of inflammation, such
as C-reactive protein (acute phase protein
or CRP) and plasma viscosity (PV). Of these
tests, CRP changes most rapidly in response
to inflammation and PV can be more sensitive
and specific for certain disorders such as
rheumatoid arthritis.
However, the attraction of ESR for busy
clinical environments such as hospitals is the
ease of use and lack of complex laboratory
equipment required. ESR also takes many
different proteins into account, making it
the method of choice for doctors wanting an
initial, broad test for inflammation.
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How to Buy ESR Analyzers
4. Meet the ESR experts
Kathy Kalinowski founded
ProSource Lab Consulting, LLC
in 2014 and has since been
providing a variety of consulting
services to a diverse mix of physician
practices for their in-office laboratories.
What are the common challenges or pitfalls of
ESR analysis?
The ESR test is a good example of how rapidly
new test methods have been introduced to
achieve safer and more efficient testing and
it deserves a good quality review. Many of
the challenges with ESR analysis are method
dependent and have been resolved with many
modified Westergren methods. Since there
are many new technologies and instruments
that are addressing the concerns of ESR
testing, it is vitally important to address the
harmonization of ESR testing.
re-analytic testing phase: Proper specimen
P
collection and mixing is required to prevent
hemolysis and to avoid coagulation. Specific
package insert guidelines should be
reviewed and followed for proper collection
and storage. Generally, ESR testing should
be performed within four hours if left at
room temperature, but specimens may be
refrigerated for up to 12 hours if brought to
room temperature and mixed well prior to
testing. Due to this short stability window,
referred specimens often have a high
sample rejection rate.
Analytic testing phase:
•Q
uality control must be performed
following the package insert guidelines
and in accordance with state and federal
regulatory agencies. Proper mixing of the
tube is essential, and the tube or vial
will have a minimum fill line to ensure
an accurate read. Manual methods also
require the ESR rack to be placed on a
level surface, free from vibration.
•O
ne very serious consideration when
selecting methods is the exposure risk
to the testing personnel. Manually filling
tubes with whole blood (and manipulation
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of pipettes with manual methods)
requires personal protective equipment
(PPE) and adequate barriers. Positive
sample identification can also be
particularly challenging with manual
analysis as the pipette needs to be free
of labels for a proper read.
•T
he timing of manual tests needs to
be exact; if this read is missed, a new
test needs to be set up, thereby
increasing the turnaround time and
risking the possibility of insufficient
whole blood for repeat testing. This
one-hour method places practical
limitations on laboratory workflow.
ost-analytic testing phase: Alternate
P
methods, such as erythrocyte aggregation,
and Westergren methods are not
interchangeable and the chosen method
should be identified on the patient report.
“It is vitally important to
address the harmonization
of ESR testing”
What should one look for in an ESR analyzer?
Most important are features that provide
maximum employee and patient safety,
and accurate and reliable testing, such
as closed-tube systems, positive sample
identification, onboard mixing, random access
testing, interface capability, and adequate
throughput to meet the lab needs.
I would recommend the Excyte automated
ESR analyzer as this line contains scalable
products with many of the key features
mentioned above. Most importantly,
the Excyte can be operated using the
closed-tube system with random access
capabilities. Other features such as
interfacing, barcode scanning, results
printing, and a 30-minute read time
ensure positive patient identification and
efficient operations.
Todd Proud is a medical
technologist with American Society
for Clinical Pathology (ASCP)
certification and is currently the
technical support manager at ELITechGroup.
What are the common challenges or pitfalls of
ESR analysis?
It is my opinion that all methods should be
compared to the gold standard Westergren
method. Over time, ESR analysis has drifted
away from this method and it has caused a
lot of confusion concerning accurate testing.
Therefore, providing education, of all the
different methods of ESR analysis, is of great
importance.
The collection and timely delivery of the
sample can also sometimes be challenging
and the preparation of the sample for testing
can be more difficult with some methods and
create biohazard challenges.
“Providing education is of
great importance”
What are the benefits of a tried and
tested method?
The Westergren method was developed in
1921 and is still considered the gold standard
for ESR testing. This is because it has
provided a consistent method that has been
used for almost 100 years and still gives the
most accurate and consistent results.
What should one look for in an analyzer?
The first thing you should be looking for
is how the analyzer compares in terms of
methodology and result correlation to the
gold standard Westergren method. You
also need to look at ease of sample
collection, ease of sample analysis, and
the dependability and technical support,
which is essential to ensure your analyzer
is always operational. Finally, the reputation
of the system you are purchasing is important
and the Excyte range is designed to surpass
every one of the above points.
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How to Buy ESR Analyzers
What ESR solutions does ELITechGroup offer?
The Excyte portfolio offers all you need to
ensure quality in your ESR analysis, including
a wide range of analyzers to meet the needs
of any sized lab, such as the Excyte Mini,
Excyte 20, and Excyte 40. There is also an
Excyte line of direct-draw blood collection
tubes, available in glass or unbreakable
plastic, or you can use tubes that you pour
the appropriate blood into before analysis.
ELITechGroup also has the ACCU-SED quality
control material and a peer group quality
assurance program called VQC to help assure
the most accurate results.
Top tips from the experts:
• Choose a method that closely follows and correlates to the Westergren
ESR method
• Automate to improve safety and efficiency in sample collection,
preparation, and analysis
• Use a closed-tube system to minimize exposure and eliminate a possible
sharps incident
• Train your testing personnel thoroughly and perform competency
assessment as required
• Utilize a proven quality control and quality assurance program
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How to Buy ESR Analyzers
5. ESR and COVID-19 management
Though ESR lacks diagnostic specificity, this
measurement could be a particularly valuable
tool for the management of patients affected
by COVID-19.
Measured ESRs increase with the severity
of inflammation present in the body and
recent studies have also shown that more
severe COVID-19 cases show more prominent
“Common laboratory findings among
hospitalized patients with COVID-19 include
elevated inflammatory markers such as
Ferritin, CRP, and ESR. Many studies focus on
the relevance of CRP levels in these patients,
but there have been some cases of significant
ESR findings that make this a relevant test in
the management of COVID-19 cases.”
Kathy Kalinowski,
ProSource Lab Consulting
elevations in ESR. This reflects the
heightened inflammatory response and
subsequent expression of acute-phase
proteins. Therefore, ESR could help clinics
rapidly distinguish between severe and
non-severe COVID-19 cases, ensuring early
diagnosis, effective screening, and improved
prioritization of care.
“This is still a new and uncharted subject.
We are just finding out that monitoring
inflammation in Covid-19 patients can be
helpful in determining a patient’s progress or
lack of progress. ESR is the most widely used
method for monitoring inflammation so it is
logical that it may be a useful method
to assist physicians with the treatment
of these patients.”
Todd Proud,
ELITechGroup
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How to Buy ESR Analyzers
6. Summary & acknowledgments
We hope that this eBook has provided
you with some key considerations when
choosing an ESR analyzer and complementary
technology. Many different types of ESR
instrumentation and analysis methodologies
exist in the market and selecting the right
equipment for your lab’s needs may seem like
an overwhelming task.
However, SelectScience has a
comprehensive range of resources, videos,
and exclusive interviews that capture
expert opinions and showcase the latest
developments in technologies like this to
help simplify your choice. Plus, you can read
reviews written by fellow scientists and
healthcare professionals, adding a valuable
dimension to your purchasing decision. We’d
love to hear from you, so please feel free
to share your experience and successes by
leaving a 2-minute review.
Acknowledgements
This eBook was produced with help and
guidance from the following individuals:
•D
ianna Poissant, Senior Director of Global
Sales and Business Development, ESR,
ELITechGroup
•K
athy Kalinowski, Founder and President,
ProSource Lab Consulting, LLC
• Todd Proud, Director, Technical Support,
ELITechGroup
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How to Buy ESR Analyzers
7. Editor’s Picks
Excyte® 20 Automated ESR Analyzer
by ELITechGroup
Excyte® Mini Automated ESR Analyzer
by ELITechGroup
“This is a great sedimentation rate analyzer and
is very reliable and accurate. This analyzer is very
easy to use: it positively identifies each specimen,
mixes it and sends results across to our LIS,
all with minimal user effort.”
Spencer Waitman,
Medical Park Family Care Inc
“Best decision ever! This is a great product! We
were using the Westergren method and making
the switch to this automated method was
probably the best thing our lab did. This
instrument is user friendly, quick, easy, and
reliable. Highly recommend this product.”
Michael Iodice,
Beth Israel Deaconess Hospital-Milton
ESR-Chex Plus
by Streck Inc.
EZ-Rate™ ESR Pipette
by Globe Scientific Inc.
“Definitely would recommend this product.
It is a great product for the clinical laboratory.”
Terri Tucker,
Frances Mahon Deaconess Hospital
“The EZ-Rate allows an easy procedure for
the ESR. It is a good selection for ESR manual
method. Globe Scientific is a good company
for laboratory consumables.”
Carlos Alfredo Torres,
Labcare de Colombia ltda
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