1. Performing a Erythrocyte Sedimentation Rate

2. Erythrocyte Sedimentation Rate • The erythrocyte sedimentation rate (ESR or sed rate) is a test measuring the rate at which erythrocytes (RBCs) settle. • This test is used to diagnose inflammation and inflammatory disorders. • The test is also used to monitor the treatment of an inflammatory disorder. • A sample of anticoagulated blood, commonly EDTA, is placed into a tube and the blood is allowed to settle. • After a specific amount of time, per the procedure used, the amount of RBC settling is measured.

3. Erythrocyte Sedimentation Rate • Performing an ESR • To perform a manual ESR test you need a calibrated tube filled with anticoagulated blood. • The RBCs will settle toward the bottom leaving plasma at the top area. • The sample is left for a specified amount of time. • At the end of the time period, you measure the distance from where the sample started to the settled RBCs. • Most healthy people have slow ESR rates. • In patients with specific inflammatory disorders, the rate of sedimentation is faster. • Sometimes the faster the settling the worse the severity of the disease.

4. Erythrocyte Sedimentation Rate • Factors effecting an ESR include….. • The plasma’s properties  if rouleaux is present • Rouleaux is when the RBCs form stacks • Rouleaux increases the mass of the RBCs and increases the rate of sedimentation. • The RBC’s properties • Large RBCs (macrocytes) settle faster than small cells (microcytes). • Irregular shaped cells cannot settle as fast and result in a slower rate of settling. • Spherocytes (small compact cells) fall at a slower rate. • The rate of settling is also affected by the number of RBCs present

5. Erythrocyte Sedimentation Rate • Factors effecting an ESR include….. • Way the procedure is carried out • The settling tube must be kept upright, straight, and standardized • Counter should be level • Temperature should be kept constant • Blood sample should be used within 2 hours of collection and well mixed • Test must be timed correctly • There are several methods used for performing an ESR. • Manual methods • Automated methods

6. Reference Ranges • Each method has its own reference values. • Reference values differ slightly depending on gender and age. • Most range from 0-20 mm/hr