Erythrocyte Sedimentation Rate (ESR) Solution and Procedure
Erythrocyte Sedimentation Rate (ESR) Solution
Sample for ESR
- Blood in EDTA or oxalate can be used.
Principle of ESR
- ESR test is based on the principle of sedimentation.
- When the blood in an anticoagulant is left, undisturbed RBCs will settle down in the container, or the Wintrobe tube marked 0 to 100 mm.
Definition of ESR
- This is the speed of sedimentation of red blood cells in plasma for one hour.
- Erythrocytes sedimentation rate (ESR), also known as sed rate, is a nonspecific test.
- ESR indicates acute and chronic inflammatory processes.
Indications for ESR
- This is a nonspecific test but, when raised, has great significance.
- The best test to diagnose occult disease.
- Diagnose and monitor temporal arteritis.
- Diagnose and monitor the Polymyalgia rheumatica.
- Monitoring Hodgkin’s disease.
- Advanced Malignancies.
- ESR is raised in myocardial infarction, while it is normal in angina.
Factors influencing ESR
- Plasma protein:
- RBCs suspended in the plasma form few aggregates of RBCs in normal blood. So the rate of sedimentation is slow.
- In the case of proteins or globulins, a rouleaux formation will give a false value. So acute phase protein affects the ESR.
- Number of RBCs:
- ESR depends upon the number of RBCs; decreases in anemia, the number of RBCs settles down rapidly.
- In the case of polycythemia, RBCs settle slowly, and ESR is low.
- The shape of RBCs:
- Changes in the shape of RBCs affect the ESR like in Sickle cell anemia; ESR may be low or zero.
- Size of the RBCs:
- Macrocytes cells settle more rapidly than microcytes because of their large size.
Technical factors affecting ESR, giving false increased value:
- False increased ESR sees in:
- Test when reading after one hour. or before one hour.
- When there is improper dilution with the anticoagulant.
- When the tube is not vertical and is tilted to one side. Even a 3 ° angle can increase the ESR by 30%.
- If there is a vibration of the tube during the test.
- If blood is not mixed properly or there are micro-clots.
- The test is done at room temperature >25 °C. Keep the temperature constant between 20 °C to 25 °C.
- Don’t operate the centrifuge machine on the same table.
- Don’t move the ESR rack during the process.
- Use the fresh blood with EDTA-anticoagulant whole blood.
- Fill the ESR tube to the top and avoid any bubbles in it.
Technical factors affecting ESR and giving false lower values:
- When the test is read for less or more than one hour.
- Improper mixing of the blood.
- Improper dilution of the blood.
- If the blood temperature is low.
- If there are air bubbles in the tube.
- If the room temperature is <20 °C.
Procedure for ESR
- Analytical balance.
- Trisodium citrate (analytical grade).
- Distal water.
Method to prepare ESR solution:
- Weigh 3.8-grams Trisodium citrate/100 mL of water.
- Suppose you are preparing 500 mL of ESR solution.
- Take 19 grams of Trisodium citrate.
- Dissolve in 500 mL of distal water.
- Mix thoroughly.
Procedure How to do ESR by Wintrobe method:
- ESR should be done within 2 hours of the collection of the blood.
- Blood can be kept at 4 °C for 6 hours. Now bring the blood to room temperature.
- Take 0.2 mL of ESR solution + 1.8 mL of oxalate blood or blood in EDTA.
- Fill the Wintrobe ESR tube. (mix the blood thoroughly before filling the tube).
- Mount in the ESR stand.
- Start the clock for one hour.
- Record the result after one hour.
- That is the ratio of settled cells and above clear plasma.
- The temperature should be kept between 20 to 25 °C.
Procedure for ESR by Westergren method:
- The pipette is graduated from 0 to 200 mm, and the holding rack is used.
- This method is more sensitive than the Wintrobe method.
- In this case, blood is diluted with 3.8% sodium citrate.
Zeta sedimentation rate (ZSR)
- It is not affected by anemia or globulin proteins.
- The normal range is the same for males and females. It uses a small amount of blood.
- This is good for children because of the small blood volume.
- It is calculated from the hematocrit and zitacrit and reported as a percentage.
- Procedure for Zitacrit:
- A small-bore capillary tube is filled with blood from the finger prick.
- This capillary is spun in the special centrifuge called the Zetafuge (Coulter diagnostic).
- This tube is read on the special reader to get the value called zitacrit.
- Calculation as %: Zitacrit (% of sedimented RBCs)/hematocrit = Result expressed as % (percentage).
- Reference values of ZSR for all ages:
Reference range % value Normal 40 to 51% Borderline 51 to 54% Raised level ≥55%
Automated Mini-Ves ESR:
- Automatic Mini-Ves ESR measures in 20 minutes instead of one hour.
- This 20 minute ESR reading correlates to the 1-hour Westergren method.
- 1mL of sample is drawn up into a 0.109 mol/L sodium citrate solution.
- It is placed in the Mini-VES machine.
- This instrument record the reading via its optical assembly.
- The second reading is recorded after 20 minutes to give the ESR value.
|Child||0 to 10|
|<50 years||0 to 15||0 to 20|
|>50 years||0 to 20||0 to 30|
|Gender||Wintrobe mm/Hour||Westergren mm/hour|
Increased ESR Value:
- Severe Anemia.
- Increased plasma globulins.
- Increased plasma fibrinogen.
- Multiple myelomas.
- Acute and chronic inflammatory conditions.
- Autoimmune inflammatory diseases.
- Chronic renal failure.
- Cancers (malignant tumors).
- Acute myocardial infarction.
Decreased ESR value:
- In the case of Sickle cell anemia.
- Increased plasma viscosity.
|Clinical diseases||ESR is raised||ESR not raised|
|Other miscellaneous diseases||
Summary of the erythrocyte sedimentation rate (ESR):
- This is a simple and nonspecific test to find the presence of the inflammatory process.
- It helps monitor conditions like anemia, renal diseases, acute myocardial infarction, and collagen diseases.
- It does not help to diagnose the disease. The normal ESR does not rule out malignancy and other serious diseases.
- It only helps to see the progress of the disease.
- ESR is a good indicator of hidden diseases like tuberculosis, SLE, and subacute bacterial endocarditis.
- ESR will differentiate between:
- AMI vs angina pectoris.
- Acute appendicitis vs ruptured ectopic pregnancy.
- Rheumatoid arthritis vs osteoarthritis.
- Acute vs silent gout.
- Iron deficiency anemia vs anemia of acute or chronic diseases.
- NOTE: Please see more details on ESR in CBC.
Question 1: What is the value of ESR in myocardial diseases
In acute myocardial infarction is raised while it is normal in angina pectoris.
Question 2: What is the value of ESR in RA and osteoarthritis?
ESR is raised in RA and is normal in osteoarthritis.