ESR, Blood Grouping & Hemostasis Lecture Notes PDF

Dr. Maryam Mosad Elmasry Lecturer of physiology 1  Chapter BLOOD PHYSIOLOGY Erythrocyte Sedimentation Rate (ESR)  Erythrocyte Sedimentation Rate (ESR) Definition: It is the rate of sedimentation of RBCs in...

Dr. Maryam Mosad Elmasry Lecturer of physiology 1  Chapter BLOOD PHYSIOLOGY Erythrocyte Sedimentation Rate (ESR)  Erythrocyte Sedimentation Rate (ESR) Definition: It is the rate of sedimentation of RBCs in anticoagulated blood kept in a vertical narrow tube. RBCs sedimented to the bottom of the tube, leaving a layer of clear plasma above it. (The RBCs sediment because their density is greater than that of plasma)  Erythrocyte Sedimentation Rate (ESR) Determinants of ESR: 1) Plasma proteins: 2) RBCs count: globulins or fibrinogen…helps rouleaux Anemia ………..fast sedimentation… formation.. increase ESR increase ESR albumin….. helps rouleaux formation… increase ESR Polycythemia.....slow sedimentation… decrease ESR  Erythrocyte Sedimentation Rate (ESR) Westergren’s method Requirements: 1. Westergren’s tube: Graduated 0-200 mm from above downwards. 2. Stand for westergren’s tube. 3. Timer or watch.  Erythrocyte Sedimentation Rate (ESR) Procedure: 1. Mix 2 ml of venous blood to 0.5 ml of sodium citrate solution. This will give a blood : citrate ratio of 4 : 1 2. Fill the Westergren’s pipette with blood to exact zero mark. 3. Transfer it to the Westergren’s stand and confirm that there’s no leakage of blood. 4. Leave the pipette for one hour & then calculate the ESR by measuring the distance between the top of the plasma and the top of the sedimented red blood cells. Express your results as: ……….. mm/h. Erythrocyte Sedimentation Rate (ESR) 1 hour Normal values ✓ Males: 4-6 mm/h ✓ Female : 8-10 mm/h.  Erythrocyte Sedimentation Rate (ESR) Increase ESR Decrease ESR Physiological Pathological Low protein: fibrinogen or gamma-globulins Infection, Inflammation, Female during Malignancy, Fractures …. Pregnancy , Menstruation & (elevated gamma-globulins or Lactation Polycythemia fibrinogen) Spherocytosis, Sickle cell After exercise Anemia (inhibit rouleaux formation)  Erythrocyte Sedimentation Rate (ESR) Clinical significance of ESR: Many factors affect the ESR making it extremely non-specific. So, ESR is not Diagnostic but it is Prognostic That helps in monitoring disease activity or response to therapy Blood Grouping  Blood Grouping using Slide Method Indications of blood grouping: 1. Blood transfusion. 2. Medicolegal (good –ve &bad +ve). 3. Pregnant ladies (erythroblastosis fetalis).  Blood Grouping using Slide Method Procedure: Place one drop of anti-A, anti-B and anti-D sera on a clean slide. Puncture your thumb with a sterile lancet and allow one drop of blood to contact each of the three anti-sera. Mix the blood with anti-sera using different small wooden sticks and tilt the slides Observe the results within 2-3 minutes  Blood Grouping using Slide Method Observation: Agglutination of the RBCs is indicated by Granular appearance of the blood sample Blood Grouping using Slide Method Blood Grouping using Slide Method Anti A Anti B Anti D  Assessment of Hemostatic Function  Hemostasis Spontaneous Stoppage of bleeding from an injured blood vessel without hemostasis minor injury will be life threatening  Stages of Hemostasis Local Vasoconstriction Platelet Plug formation Fibrin clot formation Vascular repair 1- Local Vasoconstriction: Mechanical ( Local myogenic) Chemical ( TXA2, Serotonin) Nervous (neurogenic reflex) 2- Platelet plug formation (Temporary plug): Loose Adhesion (VWF) Activation Secretion (ADP,TXA2 ,PF3) Aggregation(ADP) Why is the platelet plug limited to the site of injury? 3- Fibrin clot formation (Definitive plug): Firm Intrinsic Extrinsic pathway pathway Common pathway  Assessment of hemostatic function Bleeding time Coagulation tests Prothrombin time (PT) Activated partial thromboplastin time (aPTT)  Bleeding Time It is the time required to stop bleeding from injured blood vessel by platelet plug formation. Injury VC Platelet plug formation. So, it assess both vascular wall integrity, and platelets ( number and function). Done by Filter paper test. Normal Range: 2-5 min Procedure: 1- Sterile the little finger ( the best site is the lobule of ear) with alcohol. 2- Remove the blood drops every 15 sec by touching the puncture site with filter paper, without pressing or squeezing, repeat till bleeding stop. 3- Count the number of blood spots on filter paper, calculate the time in min. Bleeding time = number of blood drops / 4 Causes of Prolonged bleeding time: 1- Vessel wall defect e.g. Scurvy. 2- Platelet defect: Quantitative defect (Thrombocytopenia) Qualitative defect (Thrombocytopathia).  Prothrombin time (PT) Test the integrity of Extrinsic clotting pathway Normal Range: 10-12 seconds Causes of prolonged PT test: ❑Vitamin K deficiency ❑ Liver disease as in Obstructive Jaundice ❑ Oral anticoagulant such as warfarin  Activated Partial Thromboplastin Time (aPTT) Test the integrity of Intrinsic clotting pathway. Normal Range: 25-40 seconds Causes of prolonged aPTT test: ❑Hemophilia ❑ Liver disease ❑ Heparin therapy