Hematology Agriculture Lecture 1 (PDF)

Medical analysis course Presented by Dr. kareman Elsaid Elabd Lecture 1: Introduction Laboratory errors The laboratory units Sampling CBC ESR Lab safety  The introduction of medical analysis The importance of medical analysis specialist ...

Medical analysis course Presented by Dr. kareman Elsaid Elabd Lecture 1: Introduction Laboratory errors The laboratory units Sampling CBC ESR Lab safety  The introduction of medical analysis The importance of medical analysis specialist  The laboratory errors The medical laboratory workflow (Vein to brain cycle ) The time when a physician orders a laboratory test And All steps between The results returned back to the physician  The laboratory workflow consists of three stages Pre-analytical phase Analytical phase Post-analytical phase  Pre-analytical phase This phase deals with the following: Test ordering (from physician or in the laboratory).  Recording patient data (complete name, age, sex, patient phone number, patient address, physician name)  Collection and transport of specimens  How improve the quality of pre-analytical stage? 1. Reading the request form carefully. 2. Do not deal with more than one patient at the same time. 3. Ask the patient for medications in: Diabetes, Coagulation, Endocrine disorders and pressure. 4. Speak slowly and clearly and give simple, accurate instructions. 5. It is preferred to be sure that the sample is correct before the patient leave the laboratory 6. Apply the precautions of sample collection  Analytical phase This phase deals with the following:  Specimen processing and storage.  Preparation of reagents and instruments  Perform the test and calculate the result How improve the quality of Analytical stage? 1. Good education and training is essential. 2. Each laboratory should have a standard operating manual. 3. Use only clean tools and high quality chemicals. 4. Use your eyes to estimate volumes and colors. 5. Specialist must finish his work completely before leaving the shift. 6. It is advisable to preserve all samples for 24 hours after analysis before get rid of it. 7. Quality control must be done routinely to ensure good results (internal and external).  The quality control  is a measure of precision. “ How well the measurement system reproduces the same result over time and under varying operating conditions”. Laboratory quality control material is used at:  the beginning of each shift,  after an instrument is serviced,  when reagent lots are changed,  after equipment calibration,  When patient results seem inappropriate. it is used to detect Errors in the analytical process prior to the release of Results.  What is the difference between internal quality control and external Quality control?  The internal control Internal Quality control monitors the daily precision and accuracy of methodologies, personnel, and instruments. The External control maintains long term accuracy.  post-analytical phase This phase deals with the following: Interpretation of results. Reporting the results (patient name, physician name, sex, test name, test results, measurement unit, reference range and comment if found). How improve the quality of post-analytical stage? 1) All results must be recorded in worksheets (also record special notes as dilutions). 2) Check all reports carefully after writing (before printing). 3) Check again after printing (revised the normal range and unit). 4) If the result dose not accord with that expected for the patient the test should be repeated. 5) If you suspect in samples validity do not hesitate to ask for another sample from the patient  The laboratory divisions The hematology The molecular The clinical biology and virology chemistry unit unit unit The microbiology The immunology unit The parasitology and hormones unit unit The histopathological unit Sampling  Blood Sampling Types of Sampling Urine Sampling Stool Sampling Sputum sampling Semen Swab Sampling (throat, nasal, eye & wound)  Biological fluids Histopathological samples CSF Sampling (cerebrospinal fluid ). Peritonial fluid Pleural fluid Synovial fluid  Blood Sampling How to Take??? I. Selecting the vein site The best choice is Median Cubital Vein Good blood flow Most superficial & femoral artery  II. Disinfection the area with 70% alcohol swab Circular motion and from the site to outward Antiseptic should be dry 15-20 sec to avoid hemolysis The area should not be touched III. Apply a tourniquet about 2-3 inches above the site  IV. Using a syringe and non- vacum vacuette Advantage:  Cheaper  Not extra accessory requiry Disadvantage  Improper volume  Haemolysis  Using a vacuum Vaccutiner Advantages:  Maintain proper volume of blood  Safe & Speedy  Reducing the risk of haemolysis Disadvantages:  not suited for small veins.  Using a Butterfly needle Disadvantages.  The risk of hemolysis  It is difficult to collect large quantity of blood as well as in multiple vacuette Advantages:  Useful in infants & children  Blood collection tubes: Serum separating tubes (SST) Plasma separating tubes (PST) Tubes may be empty, or contain gel or silicon at the bottom of tube Tubes may contain anti-coagulant as EDTA or sodium citrate or Sodium Heparin or Lithium Heparin or Sodium Fluoride or Potassium Oxalate The difference between plasma and serum Contain total protein (Albumin + Contain total protein Globulin)+ Fibrinogen (Albumin + Globulin) Plasma = Serum + Fibrinogen  Plasma Separating Tubes (PST) Top Color Additives Principle Uses Lavender or EDTA The strongest anti-coagulant Hematology (CBC+ pink Dose= 1to2g/l Ca+2 chelating agent ESR+ Hb A1c +NH3) of blood Blood bank (blood group+ cross matching) Light Blue Sodium Citrate The strong anti-coagulant - PT, APTT, INR,D- 2g/l Ca+2 chelating agent dimer (9:1 blood sodium citrate ratio (3.2% Black sodium citrate) tube 3.8% sodium citrate (4:1) - - ESR Sodium Heparin binds to Thrombin and Enzymes (LFTs, Green Heparin or inhibits the second step in the KFTs, lipid, Glucose, Lithium coagulation cascade ckmb, tropnin) Heparin (Prothrombin Thrombin) Hormones (T3,T4) Heparin Fibrinogen Fibrin ABG Top Color Additives Principle Uses Gray -Sodium Fluoride Fluoride inhibits Glucose tests (especially when 2g/l glycolysis, and testing will be delayed), blood -Potassium Oxalate oxalate prevents alcohol, lactic acid clotting by precipitating calcium. Top Tubes Serum Separating Additives Tubes (SST) Uses Principle Red ------ Enhancing the Serology Sometimes it has formation of -Antibodies gel or silicon at the blood clot. -Hormones(PTH ,T3,T4) bottom of tube to -Drugs reduce hemolysis Clot activator Virology(HIV,HCV,HBV Ab, promotes blood HBV Ag) clotting with glass Chemistry (CRP, or silica particles. Gold LFTs,KFTs,LP, Gel separates serum from cells FBS,RBS,PPBS,CKmb, troponin, Electrolytes, IL6, procacitonin) Electrolytes (Na+, K+, Mg+, Cl, Ca, P).  Order of Draw Blood culture tube Citrate tube Plain tube Heparin tube EDTA tube Fluoride tube Order of Draw Why Blood culture tube collected first? Avoid surface contamination by Hands and Vacuette Why plain tube is take after the citrate tube ??? Plain tube –Clot activated This contaminate citrate tube Low result of PT Why Heparin tube is take after the plain tube??? Heparin contain Sodium or Potassium or Lithium salt. So it contaminate plain tube with Sodium or Potassium or Lithium salt. So result of Sodium or Potassium or Lithium is high if heparin tube is collected before plain tube. Why is EDTA tube take after the Heparin tube??? EDTA chelate calcium In plain tube ca+ result is low So Heparin and Plain tube collected before EDTA. Why Fluoride tube is take after the EDTA tube ?? Fluoride can contaminate EDTA tube if collected before EDTA Fluoride can distorted Red Blood cell Morphology. So Peripheral smear can not be reliable. Preanalytic Interference In Sample Haemolysis Reddish discoloration of serum/plasma due to rupture of RBCs. Factor causing haemolysis Sampling  Inject forcefully in vacutte,  Drawing from small vein, or from rupture vein.  Storage (Freezing): Due to high or low temp.  Vigorously shaking of blood (trasnporatation). Icteric Yellowish discoloration of Serum due to high bilirubin. Lipemic Milky or Turbid appearance of Serum due to high Triglyceride  2 3 4 1  Function of blood Blood is considered a specialized form of connective tissue help in: 1- Replace of exchange of substance between interstitial fluid and external environment. 2- Transport 3- buffer function 4- keep body temperature relatively constant 5- hemostasis 6- Defense function Physical and chemical reactions Viscosity Viscosity of Plasma is 1.2-1.3 times that of water, Viscosity of whole blood is 2.4 times of plasma pH plasma pH 7.35- 7.45 Hematopoiesis (hemopoiesis) Blood cell formation Occur in red bone marrow of axial skeleton, girdles and proximal epiphyses of humers and femur Hemocytoblasts (hematopiotic stem cells) Give rise to all formed elements. Hormones and growth factors push the cell toward a specific pathway of blood cell development New blood cells enter blood sinusoids Stem cells Primitive; self-replicate and differentiate to become increasingly specialized progenitor cells which form mature cells  Process regulated by growth factors (interleukins, erythropoietin, thrombopoietin, G-CSF) Early lineage division between progenitors for lymphoid and myeloid cells Erythropoiesis Red blood cell production - A hemocytoblast is transformed into proerythroblast. - Proerythroblast develelp into early erythroblast. - - Phases in development - 1- Ribosome synthesis - 2- hemoglobin accumulation - 3- Ejection of Nucleus and formation of reticulocytes - (Reticulocytes then become mature erythrocytes) Regulation of Erythropoiesis  Too few RBCs leads to Tissue hypoxia.  Too many RBCs increases blood viscosity.  Balance between RBCs production and destruction depend on  Hormonal controls  Adequate supplies of iron, amino acids, and vitamins B. Hormonal control of Erythropoiesis Erythropoietein (EPO): -Direct stimulate for erythropoiesis. - Released by kidneys in response to hypoxia Causes of Hypoxia  Hemorrhage or increased RBCs destruction reduces RBCs numbers.  Insufficient hemoglobin (e.g., iron deficiency).  Reduced availability of O2 (e.g., high altitudes).  Smoking.  Blood composition Plasma WBCs Thrombocytes RBCs Blood volume: 70-80 ml/Kg Average of total volume is 5 liters  Components of plasma (55%) 90% water 8% solutes 2% others Organic Proteins nutrients Albumin (60%) Carbohydrate, Alpha and beta Amino acids, globulins fatty acids, Gamma globulins vitamins Fibrinogens Hormones Electrolytes; minerals ions Gases Metabolic waste: Co2, urea Serum is a liquid that remains after blood clots. Its plasma without clotting factors and fibrenogin. Erythrocytes =RBCs (4 to 6 million/micro liter) ( 5.5 millions/mm3 males) ( 4.5 millions/mm3 females) (Erythocyte 7.5µ m in diameter) Produced in the bone marrow and lose nuclei when reach blood stream ( without nuclei & mitochondia). Flatten Biconcave shape which makes them flexible. Contain hemoglobin which carries oxygen. Have circular outline with central pallor. Life span is 120 days before they are removed by spleen. Role of R.B.Cs and Hemoglobin Hemoglobin is the most important component of red blood cells. It is a red pigment composed of heme (blood), which binds (store) oxygen and Globin is a protein. In the lungs, oxygen is exchanged for carbon dioxide (Gas exchange process). NR M: 13.8 to 17.2 g/dL NR F: 12.1 to 15.1 g/dL Hemoglobin Biochemistry  Hemoglobin variants Hemoglobin A Hemoglobin A2 Hemoglobin F It has a normal The most usually less than range of 1.5- 3.5%. common 3% but varies hemoglobin from 3%–10% in type with a about 20% of normal infants. amount over After the age of 2 95% years, Hb F is Hemoglobin Bart normally less Abnormal than 2%, and Hemoglobin S Hemoglobin H only traces of Hb Characterized Sickle Abnormal F (