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Introduction ⬇

Sedimentation occurs when the erythrocytes clump or aggregate together in a columnlike manner (rouleaux formation). These changes are related to alterations in the plasma proteins. Normally, erythrocytes settle slowly because normal RBCs do not form rouleaux.

The erythrocyte sedimentation rate (ESR) is the rate at which erythrocytes settle out of anticoagulated blood in 1 hour. This test is based on the fact that inflammatory and necrotic processes cause an alteration in blood proteins, resulting in aggregation of RBCs, which makes them heavier and more likely to fall rapidly when placed in a special vertical test tube—the faster the settling of cells, the higher the ESR.

The ESR should not be used to screen patients with no symptoms for disease. It is most useful for diagnosis of temporal arteritis, RA, and polymyalgia rheumatica. The sedimentation rate is not diagnostic of any particular disease but rather is an indication that a disease process is ongoing and must be investigated. It is also useful in monitoring the progression of inflammatory diseases; if the patient is being treated with steroids, the ESR will decrease with clinical improvement.

Men: 0–15 mm/hr (older than 50 years: 0–20 mm/hr)

Women: 0–20 mm/hr (older than 50 years: 0–30 mm/hr)

Newborn: 0–2 mm/hr

Children: 0–10 mm/hr.

Procedure ⬆ ⬇

  1. Obtain 5 mL of whole blood in a lavender-topped tube (with EDTA) or 3.8% sodium citrate. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered. Place the specimen in a biohazard bag.

  2. Suction the specimen into a graduated sedimentation tube and allow to settle for exactly 1 hour. The amount of settling is the patient’s ESR.

Clinical Implications ⬆ ⬇

  1. Increased ESR is found in:

    1. All collagen diseases, SLE

    2. Infections, pneumonia, syphilis, tuberculosis

    3. Inflammatory diseases (e.g., acute pelvic inflammatory disease)

    4. Carcinoma, lymphoma, neoplasms

    5. Acute heavy metal poisoning

    6. Cell or tissue destruction, MI

    7. Toxemia, pregnancy (third month to 3 weeks postpartum)

    8. Waldenström macroglobulinemia, increased serum globulins

    9. Nephritis, nephrosis

    10. Subacute bacterial endocarditis

    11. Anemia—acute or chronic disease

    12. RA, gout, arthritis, polymyalgia rheumatica

    13. Hypothyroidism and hyperthyroidism

  2. Normal ESR (no increase) is found in:

    1. Polycythemia vera, erythrocytosis

    2. Sickle cell anemia, Hb C disease

    3. Congestive heart failure

    4. Hypofibrinogenemia (from any cause)

    5. Pyruvate kinase (PK) deficiency

    6. Hereditary spherocytosis

    7. Anemia:

      1. ESR is normal in iron-deficiency anemia.

      2. ESR is abnormal in anemia of chronic disease alone or in combination with iron-deficiency anemia and can be used to differentiate these.

    8. Uncomplicated viral disease and infectious mononucleosis—normal

    9. Kidney disease with heart failure—normal

    10. Acute allergy—normal

    11. Peptic ulcer—normal

Clinical Alert

Extreme elevation of the ESR is found with malignant lymphocarcinoma of colon or breast, myeloma, and RA

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain test purpose and procedure. Assess for signs/symptoms of fever, chills, and acute infection. Obtain appropriate medication history. Fasting is not necessary, but a fatty meal can cause plasma alterations.

  2. Possible treatments include preventing cross infection and decreasing activity levels.

  3. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Have the patient resume normal activities and diet.

  2. Review test results; report and record findings. Modify the nursing care plan as needed. Counsel the patient regarding abnormal findings; explain the need for possible follow-up testing and treatment. Monitor for rheumatic disorders and inflammatory conditions.

  3. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆

  1. Allowing the blood sample to stand longer than 24 hours before the test is started causes the ESR to decrease.

  2. In refrigerated blood, the ESR is increased. Refrigerated blood should be allowed to return to room temperature before the test is performed.

  3. Factors leading to an increased ESR include:

    1. The presence of fibrinogen, globulins, C-reactive protein, high cholesterol

    2. Pregnancy after 12 weeks until about the fourth postpartum week

    3. Young children

    4. Menstruation

    5. Certain drugs (e.g., heparin, oral contraceptives; see Appendix E)

    6. Anemia (low Hct)

    7. Macrocytosis

  4. The ESR may be very high (up to 60 mm/hr) in apparently healthy women aged 70–89 years.

  5. Factors leading to reduced ESR include:

    1. High blood sugar, high albumin level, high phospholipids

    2. Decreased fibrinogen level in the blood in newborns, hypofibrinogenemia

    3. Certain drugs (e.g., steroids, high-dose aspirin; see Appendix E)

    4. High Hb and RBC count—polycythemia

    5. High WBC count

    6. Abnormal RBCs (e.g., sickle cells, spherocytes, microcytosis)