The ESR

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The ESR
A test which is often sneered at Why ?
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The ESR
OK, first of all, what is the ESR ?
ESR is an acronym E Erythrocyte Red cells S
Sedimentation settling R Rate amount in a
given time
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The ESR
OK, first of all, what is the ESR ?
how much the red cells settle in a given
time. Measured in mm/hr. Why is the hr bit
important ?
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The ESR
Next how is the test performed?
Take a tube
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The ESR
Next how is the test performed?
Take a tube Fill with blood
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The ESR
Next how is the test performed?
Take a tube Fill with blood
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The ESR
Next how is the test performed?
Take a tube Fill with blood Leave it for an hour
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The ESR
Next how is the test performed?
Take a tube Fill with blood Sedimentation occurs
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The ESR
What is it actually measuring ?
Sedimentation of red cells in a given time
Zeta potential
Which is dependent on
Red cells carry a net negative charge Which
causes them to repel each other
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The ESR
What is it actually measuring ?
Sedimentation of red cells in a given time
Something often overlooked. ESRs are Normal -
less than 10 (ish) or High - more than 10 (ish)
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The ESR
The science behind the test
An ESR is either normal or raised. If raised,
its because the cells sediment faster because
they stick together (rouleaux). More sticking
together implies less electrostatic repulsion So
the disease process is affecting the zeta
potential
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The ESR
The science behind the test
A look at acute phase reactions. Albumin
Counteracts rouleax formation Decreased in
acute phase reactions So .? raised ESR
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The ESR
The science behind the test
A look at acute phase reactions. Fibrinogen
Increased in acute phase reactions So as
its raised, albumin levels are relatively
lowered So? raised ESR
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The ESR
The science behind the test
A look at polycythaemic conditions The more
cells, the more space they need to
settle Therefore a low result
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The ESR
Next how can YOU influence the result?
There are a whole range of things that YOU can do
to change the result obtained from an ESR
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The ESR
Next how can YOU influence the result?
Time of sedimentation. The longer it is left,
the more sedimentation occurs up to a point what
point is that ?
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The ESR
Next how can YOU influence the result?
Mixing of the sample If not thoroughly
mixed, then its already partially sedimented.
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The ESR
Next how can YOU influence the result?
Temperature. Ever had a thick milk shake ? Why
can you drink one quickly in August and why does
it takes half an hour at Xmas?
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The ESR
Next how can YOU influence the result?
Vibrations. Put some marbles on the bench Drop
something heavy. What happens?
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The ESR
Next how can YOU influence the result?
Angle.
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The ESR
Next how can YOU influence the result?
Angle. In this tube the cells drop down
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The ESR
Next how can YOU influence the result?
Angle. In this tube the cells drop down
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The ESR
Next how can YOU influence the result?
Angle. In this tube the cells drop
down Gravity
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The ESR
Next how can YOU influence the result?
Angle. Wot about this tube ?
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The ESR
Next how can YOU influence the result?
Angle. Wot about this tube ?
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The ESR
Next how can YOU influence the result?
Angle. Wot about this tube ? Gravity is still
the same
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The ESR
Next how can YOU influence the result?
Angle. Wot about this tube ? Gravity is still
the same
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The ESR
Next how can YOU influence the result?
Angle. Wot about this tube ? Gravity is still
the same but the cells reach the side of the
tube and then roll down
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The ESR
Next - how can YOU cock it up ?
Angle. Wot about this tube ? Gravity is still
the same but the cells reach the side of the
tube and then roll down
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The ESR
Next how can YOU influence the result?
Clots. Why should a lump of clot in the tube
affect sedimentation ?
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The ESR
Next how can YOU influence the result?
Sufficiency.
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The ESR
Next how can YOU influence the result?
Sufficiency.
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ?
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV ie the ratio of this
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV ie the ratio of this
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV ie the ratio of this to
this
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV ie the ratio of this to
this
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV Packed cell volume is a
ratio
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV Packed cell volume is a
ratio An ESR (at one hour) is a measurement.
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The ESR
Next how can YOU influence the result?
Sufficiency. Whats the highest reading that an
ESR can be ? The PCV which is reached much
quicker with a small sample
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Earlier I said A test which is often sneered at
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The ESR is
Not specific Affected by a range of
conditions Varies with the menstrual cycle Not
diagnostic
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Why do an ESR?

• Two clinical reasons
• Monitoring of rheumatoid arthritis
• Diagnosis of temporal arteritis

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Why do an ESR?
Its a marvellous test. BECAUSE its so
non-specific a one-stop or - screen.
If someone turns up at the G.P., and claims to be
unwell, but the G.P. is unconvinced, she will ask
for an ESR.