Sed Rate By Modified Westergren: A Comprehensive Guide

The erythrocyte sedimentation rate (ESR) is a widely used laboratory test that measures the rate at which red blood cells settle in a test tube containing a blood sample. It is a non-specific marker of inflammation and can be used to monitor various conditions, including infections, autoimmune disorders, and cancers. One of the most common methods used to measure ESR is the modified Westergren method. In this article, we will delve into the details of the sed rate by modified Westergren, its principles, procedure, reference ranges, and clinical applications.

What is the Modified Westergren Method?

The modified Westergren method is a standardized technique used to measure the ESR. It was developed by Alf Vilhelm Albertsson Westergren, a Swedish physician, in the early 20th century. The method involves filling a test tube with a blood sample and allowing it to stand upright for a specified period. The rate at which the red blood cells settle to the bottom of the tube is measured and expressed in millimeters per hour (mm/h).

Principle of the Modified Westergren Method

The principle of the modified Westergren method is based on the fact that red blood cells tend to aggregate and settle more quickly in the presence of inflammation. When a blood sample is placed in a test tube, the red blood cells initially remain suspended in the plasma. However, as the cells begin to aggregate, they become heavier and start to settle to the bottom of the tube. The rate at which this settling occurs is directly proportional to the degree of inflammation present in the body.

Factors Affecting ESR

Several factors can affect the ESR, including:

• Age: ESR tends to increase with age.
• Sex: Women tend to have higher ESRs than men.
• Pregnancy: ESR can increase during pregnancy.
• Medications: Certain medications, such as corticosteroids, can affect ESR.
• Anemia: ESR can be affected by the presence of anemia.

Procedure for Measuring ESR by Modified Westergren

The procedure for measuring ESR by modified Westergren involves the following steps:

1. Collection of blood sample: A blood sample is collected from the patient using a sterile needle and syringe.
2. Preparation of test tube: A test tube is filled with a blood sample, leaving a small amount of space at the top.
3. Addition of anticoagulant: An anticoagulant, such as EDTA, is added to the blood sample to prevent clotting.
4. Incubation: The test tube is placed in a vertical position and allowed to stand for 1 hour.
5. Measurement: The distance between the top of the blood column and the top of the sediment is measured in millimeters.

Reference Ranges for ESR by Modified Westergren

The reference ranges for ESR by modified Westergren vary depending on the age and sex of the patient. The following are the typical reference ranges:

• Men: 0-15 mm/h
• Women: 0-20 mm/h
• Children: 0-10 mm/h

Clinical Applications of ESR by Modified Westergren

ESR by modified Westergren has several clinical applications, including:

• Monitoring inflammation: ESR can be used to monitor the level of inflammation in patients with conditions such as rheumatoid arthritis, lupus, and vasculitis.
• Diagnosing infections: ESR can be used to diagnose infections such as tuberculosis and pneumonia.
• Monitoring cancer: ESR can be used to monitor the progression of cancer and the response to treatment.

Limitations of ESR by Modified Westergren

While ESR by modified Westergren is a useful test, it has several limitations, including:

• Non-specificity: ESR is a non-specific marker of inflammation and can be affected by various factors.
• Lack of sensitivity: ESR may not be sensitive enough to detect mild inflammation.
• Variability: ESR can vary depending on the technique used and the operator.

Conclusion

In conclusion, the sed rate by modified Westergren is a widely used laboratory test that measures the rate at which red blood cells settle in a test tube containing a blood sample. It is a non-specific marker of inflammation and can be used to monitor various conditions, including infections, autoimmune disorders, and cancers. While it has several limitations, ESR by modified Westergren remains a valuable tool in the diagnosis and management of various diseases.

What is the normal range for ESR by modified Westergren?

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The normal range for ESR by modified Westergren varies depending on the age and sex of the patient. The typical reference ranges are 0-15 mm/h for men, 0-20 mm/h for women, and 0-10 mm/h for children.

What are the clinical applications of ESR by modified Westergren?

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ESR by modified Westergren has several clinical applications, including monitoring inflammation, diagnosing infections, and monitoring cancer.

What are the limitations of ESR by modified Westergren?

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ESR by modified Westergren has several limitations, including non-specificity, lack of sensitivity, and variability.