When the anticoagulant-containing blood is placed vertically at room temperature, the red blood cells are deposited and the ESR is actually the height of the plasma column in millimeters after an hour. In the 30-channel sediment machine, the sediment continues at a higher and constant rate, and in the third stage, the sedimentation rate slows down again. In the 30-channel sodium analyzer devices, there is an elevator that contains infrared eyes, a tube full of blood is placed between these eyes, and the elevator is constantly moving up and down, and the eyes do not see each other in the red part of the tube, but in the deposited part (yellow), they see each other and measure the distance, and thus within 30 minutes ( or 60 minutes) calculates the erythrocyte sedimentation diagram and predicts the amount of sodium in the first hour (or second hour) according to mathematical equations.
Sedimentation velocity is directly related to erythrocyte mass and inversely related to erythrocyte levels. For example, the Rolex has a high mass and a low surface area, thus increasing the rate of sedimentation. One of the most important factors in the creation of Rolex is the increase in fibrinogen, beta-globins and pathological immunoglobulins in plasma cell disorders and chronic inflammatory diseases. Positively charged proteins reduce the zeta potential and Rolex formation by neutralizing the electrostatic force of repulsion, as well as the deposition rate has an inverse ratio to the viscosity of the plasma.
Acute phase proteins and immunoglobulins modulate the Rolex by neutralizing the electrostatic force of red blood cell repulsion, meaning that the red blood cells are stacked on top of each other like a column of coins.
The everyday method of measuring sedimentation velocity is the Westergren method. The advantage of this method is the length of the pipe, which allows the maximum sediment to form. This method is commissioned by ICSH (International Committee for Standardization of Hematology).
The blood volume sodium is mixed with a volume of 3.8% sodium citrate. If the blood is taken in EDTA, 4 volumes of it are mixed with 1 volume of sodium citrate 3.8% or physiological serum. (e.g. 2 cc of blood with 0.5 cc of diluent solution)
Pipe with black cap for sampling sedimentation velocity test
Important note:
The ICSH committee introduces the deposition rate by Westerin with undiluted blood as the standard method, if the hematocrit is above 35%, the repeatability of ESR test in narrow tubes is reduced, and therefore the blood is mixed with sodium citrate, and finally the ESR value of undiluted blood can be calculated using the following formula.
-12 (undiluted blood sedimentation velocity × 0.86) = deposition velocity of diluted blood
-12 (undiluted blood sedimentation velocity × 0.86) = deposition velocity of diluted blood
In the Westergren method, blood is poured into a 200 mm column with an opening diameter of 2.55 mm, which is graded from zero to 200 mm, and after one hour, the distance traveled by red blood cells is reported in millimeters per hour (mm/h).
Sources of error
Note: In some automated systems such as Vesmatic systems, the sample is taken in special tubes such as Ves-Tec or Vacu-Tec that contains sodium citrate and is placed at an angle of 18 degrees relative to the vertical position, and the sedimentation rate is estimated in 20 minutes, which is equivalent to one hour in the Westergren method. In these systems, the basis of the reading is based on optoelectronic sensors.
Deposition velocity at an angle of 18°
Sedimentation velocity by Micro-ESR method is more widely used in children. In this method, 0.2 cc of blood is needed to fill a 230 mm plastic tube with a diameter of 1 mm.
Sedimentation velocity testing in ESR STAT plus systems is based on sample centrifugation.
| Invoices | Increased ESR | Reduced ESR |
| Protein and Fat | Increased Cholesterol, Increased Fibrinogen, Increased Gamma-Globin, Decreased Albumin | Increased albumin, increased phospholipids, increased bile salts |
| Erythrocytes | Anemia, macrocytosis | Acantocytes, Anisocytes, Spherocytes, Polycythemia, Sickle, Thalassemia, Microcytosis |
| White Blood Cells | Leukemia | Leukocytosis |
| Medications | Dextran, Heparin, Vitamin A, Procainamide, Phenylenamine, Theophylline | Salicylate, Quinidine |
| Various clinical conditions | Poisoning, infection, autoimmune disease, diabetes, kidney failure, malignancy, multiple myeloma, pregnancy, rheumatic fever | |
| Sample Requirements | A sample that has been stored in the refrigerator and has not reached room temperature | Presence of clot in the sample, delay in recording results |
| Conditions for the test | Room temperature rise, pipe tilt, vibration | Air bubble in the tube, low temperature, reducing the diameter of the tube |
Tips
| Man | Women | |
| Before the age of 50 | mm/h 15 | mm/h20 |
| Over 50 years old | mm/h20 | mm/h30 |
| Over 80 years of age | mm/h30 | mm/h24 |
The sedimentation velocity test is used to follow up the treatment of inflammatory and infectious diseases or to confirm the presence of inflammatory diseases. This test is sometimes helpful in differentiating diseases with the same picture. For example, the rate of sedimentation in osteoarthritis is normal, but in arthritis caused by rheumatic diseases and rheumatic fever, it is high. The rate of sedimentation increases in early pelvic inflammatory disease and ectopic pregnancy rupture, while appendicitis is normal in the first 24 hours.
Recently, it has been shown that sedimentation rate in sickle cell anemia is clinically important, meaning that a decrease in sedimentation rate has been observed in the absence of obstructive crises, while it increases moderately from one week to painful crises.
Sedimentation velocity testing is also used in follow-up treatment of osteomyelitis.
In stroke a value greater than 28 mm/h has a bad prognosis. In prostate cancer, a value greater than 37 mm/h is associated with disease progression and a bad prognosis. In coronary artery disease, a value greater than 22 millimeters per hour in white men is known as a risk factor. The sedimentation rate in pregnancy increases from 10 to 12 weeks and returns to normal one month after delivery.
In patients with known cancer, a value greater than 100 is usually an indicator of metastasis.
Sedimentation velocity is a useful test in the diagnosis and follow-up of polymyalgia rheumatica, or muscle aches caused by vascular inflammation, and temporal arteritis (inflammation of the temporal vascular region), in which cases the value exceeds 90 mm/h.
The emergency use of ESR can be mentioned for the evaluation of temporal arteritis, infectious arthritis, pelvic inflammation and appendicitis. Rapid measurement of ESR in Giant cell arteritis (an inflammatory vascular disease involving large to medium veins in the head area) is clinically important because a delay of a few hours in starting steroid therapy may be associated with irreversible visual impairment.
In Hodgkin’s lymphoma ESR has prognostic value and is usually less than 10 in the absence of symptoms (fever, weight loss, night sweats).
About 70% of patients with kidney cancer have an increase in ESR.
Dr. Habib A…
Golafshan is a faculty member of Shiraz University of Medical Sciences
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