ERYTHROCYTE SEDIMENTATION RATE

RAJESH MOHESS, CLT.AL.

ERYTHROCYTE SEDIMENTATION RATE (ESR)• The erythrocyte sedimentation rate (ESR) is a

nonspecific screening test nonspecific screening test indicative of inflammation

• There are two methods of determining ESR: Westergren and Wintrobe

• Studies have shown that the Wintrobe method was found to be misleading in some important cases

• As a result, the Westergren method is most widely used

ERYTHROCYTE SEDIMENTATION RATE (ESR)• Anticoagulated blood is drawn up into a tube of standardized

dimensions and left in a vertical position for exactly one hour.

• After that period the point at which the red cells have separated and settled from the plasma is recorded by reading from the scale on the side of the tube.

• This test measures the distance that RBCs will fall in a vertical tube over a given time period

• It is used as an initial screening tool and also as a follow-up test to monitor therapy and progression or remission of disease.

• The ESR is directly proportional to red cell mass

• The ESR is reported in millimeters

ERYTHROCYTE SEDIMENTATION RATE (ESR)• Although the test has been used since 1926 the phenomenon

of red cell sedimentation is still only partly understood.

• However three definite phases have been identified in the process.

• During the first, or Lag Phase, the red cells form a characteristic rouleaux pattern and sedimentation is generally slow.

• The rate accelerates in the second period, the Decantation Phase, and slows again in the final Packing Phase as red cell aggregates pile up at the base of the tube

ERYTHROCYTE SEDIMENTATION RATE (ESR)• The size of the rouleaux aggregates formed in the Lag Phase is the

critical factor affecting the final result of the ESR.

• The rouleaux itself appears to be influenced mainly by certain plasma proteins including fibrinogen, IgM and alpha2-macroglobulin.

• From the above it can be seen that the sedimentation 'rate' of the red cells is not linear.

• Further, the time taken for each of the three phases will differ between patients.

• Therefore no attempt should be made to 'estimate' the result at 1 hour by doubling the value at 30 minutes or multiplying by three after 20 minutes

ERYTHROCYTE SEDIMENTATION RATE (ESR)

• Any condition that will increase rouleaux formation will usually increase the settling of red cells.

• Specimens that are not properly anticoagulated will also affect red cell settling. EDTA is the recommended anticoagulant

ERYTHROCYTE SEDIMENTATION RATE (ESR)

EQUIPMENT

• Westergren ESR system

• Wintrobe system (tubes)

• Disposable pipette

PROCEDURE – WESTERGREN METHOD

PROCEDURE – WESTERGREN METHOD

• 1. Mix the EDTA tube on the rotator/mixer for a minimum of 5 minutes. If the sample has been refrigerated, allow 30 minutes for the sample to come to room temperature before proceeding.Hold the filling reservoir and shake downwards with a flick the wrist to force the saline to the bottomKeep upright and remove cap

PROCEDURE – WESTERGREN METHOD

• 2. Add 1ml well mixed EDTA whole blood to the filling line of the reservoir.

• 3. Replace Cap• 4. Gently mix by inversion (minimum of 8 inversions)• 5. Place on flat surface an make sure that all the blood return

back to the bottom of the reservoir

PROCEDURE – WESTERGREN METHOD• 6. Hold the reservoir firmly in one hand and the Dispette tube in the

other hand with the 180 mark towards the bottomPenetrate the cap membrane and stop

• 7. With gentle movements, continue to penetrate the reservoir towards the bottomMaking sure that the blood is rising to the top until it reaches the grommet at the zero markWhen the Dispette is fully inserted, any extra blood will be accommodated by the plugged overflow chamber

PROCEDURE – WESTERGREN METHOD

• 8. Place the fully assembled Dispette apparatus in a level stand at 90 degrees to the standRead and record the results in millimeters at exactly one hour after settling upright (distance which the cells have settled)

PROCEDURE – WINTROBE METHOD

• 1. Add well mixed EDTA blood to the zero mark of the Wintrobe tube, using a pipetteAvoid air bubbles

• 2. Place in vertical position in a rack and let sit for 60 minutes• 3. Read and record results in millimeter (distance which the cells

have settled)

ERYTHROCYTE SEDIMENTATION RATE

NORMAL RANGE

• Men 0 to 20 mm/hr

• Women 0 to 30 mm/hr

LIMITATIONS• 1. Tubes not filled properly will yield erroneous results.

• 2. Refrigerated specimens must come to room temperature for 30 minutes prior to testing.

• 3. The ESR rack must be on a level surface and free of vibration. Vibration can cause a falsely increased ESR.

• 4. Cold agglutinins can cause a falsely elevated ESR. An ESR can be performed at 37 degrees C (incubator) for 60 minutes with no ill effects.

• 5. Red cell shape and size: Specimens containing sickle cells, acanthocytes, or spherocytes will settle slowly and give a decreased ESR

• 6. Increased rouleaux formation, excessive globulin, or increased fibrinogen will increase the ESR.

LIMITATIONS• 7. Specimen must be free of clots and/or fibrin.

• 8. A tilted ESR tube gives erroneous results.

• 9. Hemolyzed samples are not acceptable.

• 10. Specimens older than 24 hours are not acceptable.

• 11. Do not pick up the stand to read results as this will affect other tests in progress. Bring the eye to the level of the top of the red cells to read accurately from the scale

• 12. Results must be read at exactly one hour, otherwise the cells with continue to sediment resulting in higher results

PATHOLOGICAL CONDITIONS ASSOCIATED WITH ESR

Increased ESR

• 1. Kidney diseaseKidney disease• 2. Pregnancy2. Pregnancy• 3. Rheumatic fever3. Rheumatic fever• 4. Rheumatoid arthritis4. Rheumatoid arthritis• 5. Anemia5. Anemia• 6. Syphilis6. Syphilis• 7. Systemic lupus erythematosus7. Systemic lupus erythematosus• 8. Thyroid disease8. Thyroid disease• 9. Elevated room temperature9. Elevated room temperature• 10. Ischemic stroke10. Ischemic stroke• 11. Temporal arteritis 11. Temporal arteritis

PATHOLOGICAL CONDITIONS ASSOCIATED WITH ESR

Decreased ESR

• 1. Congestive heart failure• 2. Hyperviscosity• 3. Decreased fibrinogen levels• 4. Polycythemia• 5. Sickle cell anemia

• < 0.5 mm/hr

ERYTHROCYTE SEDIMENTATION RATE

THE END