LAB 6 ESR PDF

physiology Lab. 6 Erythrocyte Sedimentation Rate By Assistant lecturer Noor ali salman ١  Definition Esr is a blood test that that can show if you have inflammation in your body, Inflammation in your immune system's, r...

physiology Lab. 6 Erythrocyte Sedimentation Rate By Assistant lecturer Noor ali salman ١  Definition Esr is a blood test that that can show if you have inflammation in your body, Inflammation in your immune system's, response to injury, infection, and many types of conditions, including immune system disorders, certain cancers, and blood disorders. Distance sediment in a vertical column of blood after 1 hour. detects nonspecific inflammation in your body What is the principle of ESR When anticoagulated blood is allowed to stand vertically. RBC’s settle towards the bottom of the tube under the influence of gravity resulting in packed column in a given interval of time leaving the clear plasma above. The process of sedimentation is called ESR. Why do cells settle 1. Density of RBC’s is greater than that of plasma 2. RBC’s tend to aggregate to form rouleaux. 3. Rouleaux are piled up RBC’s that become heavier & sediment faster. Mechanism of ESR 1. Normal RBC’s settle slowly as they do not form rouleaux due to the negative charge on their surface which causes them to repel each other 2. Plasma proteins especially fibrinogen & globulin adhere to the red cells membranes & neutralize the surface negative charges promoting cell adherence & rouleaux formation 3. ESR is directly proportional to the weight of the cell aggregate and inversely proportional to the surface area. What is Zeta potential is defined as the degree of negative charge on the surface of a red blood cell; it is the potential difference between the negative charges on the red blood cells (RBCs) and the cations in the fluid portion of the blood More simply, imagine RBCs as cars on a highway. 1. ↓cars (anemia)→traffic will move faster (↑ESR). 2. Cars in organized lanes (rouleaux formation)→traffic will move faster (↑ESR). 3. Plasma viscosity is the smoothness of the road. Graded pavement (↑viscosity) → ↓ESR  Procedure (Westergreen method) Sample : 3.8% tri-sodium citrated anticoagulant blood. 1.6ml of blood is mixed in 0.4ml of Tri-sodium citrate (ratio of blood to sodium citrate 4:1) Westergren tube : Length -30cm with Internal bore diameter -2.5mm Calibrated from top to bottom -0-200 Procedure: Mix the blood thoroughly and Draw blood into the tube up to mark ‘0’ with the help of rubber bulb. Transfer the tube to westergren stand & stand it vertically. Height of clear plasma on the top of the tube is measured after 1 or 2 hrs How does sodium citrate acts to prevent blood clotting? Normal values  Male – 0-5 mm in 1st hr; 6-10 mm in 2nd hr  Female -8-10 mm in 1st hr; 16-20 mm in 2nd hr Factors affecting ESR 1. Sunlight – Direct sunlight on tube increases ESR 2. Vibration – Reduces ESR 3. Hemolysis or clotted sample – ESR is less as clot traps fibrinogen and hence there is no rouleaux formation 4. Time – ESR should be estimated with in two hours of sample collection. If there is delay then the sample should be stored at4oC and test should be performed with in 6 hours. 5. Drugs – 1. Drugs like Vit A increases ESR 2. Aspirin, Cortisone and Quinine decreases ESR Clinical significance of ESR ESR is non specific hematological test for inflammation caused by infections, malignant conditions, degenerative and autoimmune diseases. ESR is raised in these conditions which is associated with increase in plasma proteins particularly fibrinogen, immunoglobulins and C-reactive protein It is a prognostic test 1. It detects the presence and severity of disease 2. It gives an idea about the activity of disease 3. Repeated ESR estimation helps in prognosis & follow up of disease Conditions with increased ESR Pregnancy Anemia and Macr-ocytosis Inflammatory disease Acute & chronic infection Tuberculosis Autoimmune diseases Conditions with decreased ESR Hyper viscosity Decreased fibrinogen levels Polycythemia Sickle cell anemia Spherocytosis Microcytosis