Erythrocyte sedimentation rate (ESR)

Erythrocyte sedimentation rate (ESR) is the rate at which the erythrocytes settle down. Normally, the red blood cells (RBCs) remain suspended uniformly in circulation. This is called suspension stability of RBCs. If blood is mixed with an anticoagulant and allowed to stand on a vertical tube, the red cells settle down due to gravity with a supernatant layer of clear plasma. ESR is also called sedimentation rate, sed rate or
Biernacki reaction. It was first demonstrated by Edmund Biernacki in 1897.
„ DETERMINATION OF ESR
There are two methods to determine ESR.
1. Westergren method
2. Wintrobe method
„ WESTERGREN METHOD
In this method, Westergren tube is used to determine ESR.
Westergren Tube
The tube is 300 mm long and opened on both ends . It is marked 0 to 200 mm from above downwards.
Westergren tube is used only for determining ESR. 1.6 mL of blood is mixed with 0.4 mL of 3.8% sodium
citrate (anticoagulant) and loaded in the Westergren tube. The ratio of blood and anticoagulant is 4:1. The
tube is fitted to the stand vertically and left undisturbed. The reading is taken at the end of 1 hour.
„ WINTROBE METHOD
In this method, Wintrobe tube is used to determine ESR.
Wintrobe Tube
Wintrobe tube is a short tube opened on only one end. It is 110 mm long with 3 mm bore. Wintrobe
tube is used for determining ESR and PCV. It is marked on both sides. On one side the marking is from 0 to 100 (for ESR) and on other side from 100 to 0 (for PCV). About 1 mL of blood is mixed with anticoagulant, ethylenediaminetetraacetic acid (EDTA). The blood is loaded in the tube up to ‘0’ mark and the tube is placed on the Wintrobe stand. And, the reading is taken after 1 hour.
„ NORMAL VALUES OF ESR
By Westergren Method
In males : 3 to 7 mm in 1 hour
In females : 5 to 9 mm in 1 hour
Infants : 0 to 2 mm in 1 hour
By Wintrobe Method
In males : 0 to 9 mm in 1 hour
In females : 0 to 15 mm in 1 hour
Infants : 0 to 5 mm in 1 hour
„ SIGNIFICANCE OF DETERMINING ESR
Erythrocyte sedimentation rate (ESR) is an easy, inexpensive and non-specific test, which helps in diagnosis
as well as prognosis. It is non-specific because it cannot indicate the exact location or cause of disease.
But, it helps to confirm the diagnosis. Prognosis means monitoring the course of disease and response of the
patient to therapy. Determination of ESR is especially helpful in assessing the progress of patients treated for
certain chronic inflammatory disorders such as:
1. Pulmonary tuberculosis
2. Rheumatoid arthritis 3. Polymyalgia rheumatica (inflammatory disease characterized by pain in shoulder and hip)
4. Temporal arteritis (inflammation of arteries of head).
„ VARIATIONS OF ESR
1. Age: ESR is less in children and infants because of more number of RBCs.
2. Sex: It is more in females than in males because of less number of RBCs.
3. Menstruation: The ESR increases during menstruation because of loss of blood and RBCs
4. Pregnancy: From 3rd month to parturition, ESR increases up to 35 mm in 1 hour because of
hemodilution.
ESR increases in diseases such as the following conditions:
1. Tuberculosis
2. All types of anemia except sickle cell anemia
3. Malignant tumors
4. Rheumatoid arthritis
5. Rheumatic fever
6. Liver diseases.
ESR decreases in the following conditions:
1. Allergic conditions
2. Sickle cell anemia
3. Peptone shock
4. Polycythemia
5. Severe leukocytosis