erythrocyte sedimentation rate
erythrocyte sedimentation rate (ESR) is a nonspecific screening test indicative of inflammation. It is used as an initial screening tool and also as a follow-up test to monitor therapy and progression or remission of disease.
**This test measures the distance that RBCs will fall
in a vertical tube over a given time period.
**The ESR is directly proportional to red cell mass and inversely proportional to its surface area.
in a vertical tube over a given time period.
**The ESR is directly proportional to red cell mass and inversely proportional to its surface area.
**The ESR is reported in millimeters.
**Any condition that will increase rouleaux formation will usually increase the settling of red cells.
Factors affecting the ESR are as follows:-
**Red cell shape and size:-
Factors affecting the ESR are as follows:-
**Red cell shape and size:-
Specimens containing sickle cells, acanthocytes, or spherocytes will settle slowly and give a decreased ESR
** Plasma fibrinogen and globulin levels:-
Increased fibrinogen or globulin levels will cause increased settling and give an increased ESR
** Mechanical and technical conditions:-
** Plasma fibrinogen and globulin levels:-
Increased fibrinogen or globulin levels will cause increased settling and give an increased ESR
** Mechanical and technical conditions:-
Surfaces that are not level will influence red cell settling. Specimens that are not properly anticoagulated will also affect red cell settling. EDTA is the recommended anticoagulant.
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Reagents and Equipment
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1- Sediplast Autozero Westergren ESR system
a-Fixed bore pipettes
b-Sedivials filled with 0.2 mL of 3.8% sodium citrate
c-Vial holder (rack)
2- Disposable plastic pipettes
3- Rotator/mixer
4- Timer
b-Sedivials filled with 0.2 mL of 3.8% sodium citrate
c-Vial holder (rack)
2- Disposable plastic pipettes
3- Rotator/mixer
4- Timer
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Limitations
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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 C (incubator) for 60 minutes with no ill effects.
5- Cell size and shape affect ESR, usually resulting in a decreased ESR result.
6- Increased rouleaux formation, excessive
globulin, or increased fibrinogen will increase the ESR.
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.
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 C (incubator) for 60 minutes with no ill effects.
5- Cell size and shape affect ESR, usually resulting in a decreased ESR result.
6- Increased rouleaux formation, excessive
globulin, or increased fibrinogen will increase the ESR.
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.
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Procedure
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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.
2- Remove the top of the Sediplast vial, which contains 3.8% sodium citrate. Using a disposable pipette, add blood to the indicated line, return the top, and mix thoroughly.
3- Insert Westergren tube into Sediplast vial with a slight twist, allowing the blood to rise to the zero mark.
4- Place the vial in the rack on a level surface.
5- Set a timer for one hour and read at the end of the hour.
6- Record the ESR in millimeters per hour.
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.
2- Remove the top of the Sediplast vial, which contains 3.8% sodium citrate. Using a disposable pipette, add blood to the indicated line, return the top, and mix thoroughly.
3- Insert Westergren tube into Sediplast vial with a slight twist, allowing the blood to rise to the zero mark.
4- Place the vial in the rack on a level surface.
5- Set a timer for one hour and read at the end of the hour.
6- Record the ESR in millimeters per hour.
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Conditions Associated With Increase and Decrease ESR
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Increased ESR
1- Kidney disease
2- Pregnancy
3- Rheumatic fever
4- Rheumatoid arthritis
5- Anemia
6- Syphilis
7- Systemic lupus erythematosus
8- Thyroid disease
9- Elevated room temperature
Decreased ESR
1- Congestive heart failure
2- Hyperviscosity
3- Decreased fibrinogen levels
4- Polycythemia
5- Sickle cell anemia
1- Kidney disease
2- Pregnancy
3- Rheumatic fever
4- Rheumatoid arthritis
5- Anemia
6- Syphilis
7- Systemic lupus erythematosus
8- Thyroid disease
9- Elevated room temperature
Decreased ESR
1- Congestive heart failure
2- Hyperviscosity
3- Decreased fibrinogen levels
4- Polycythemia
5- Sickle cell anemia
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Normal Ranges
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Men 0 to 15 mm/hr
Women 0 to 20 mm/hr
Men 0 to 15 mm/hr
Women 0 to 20 mm/hr
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