LESSON 5: HEMATOLOGY

• Heme 


  blood
• logos

  study
• primarily deals with the cellular elements of the peripheral blood and bone marrow.
• includes morphologic appearance, function, and disease of blood
• the body’s main fluid for transporting nutrients, waste products, gases, and hormones through the circulatory system
• These cells, which are formed in the bone marrow, are released into the bloodstream as needed to carry oxygen, provide immunity against infection, and aid in blood clotting.
• Total blood volume in an adult is 5 to 6 liters or 7 to 8% of the total body weight.
• Blood is analyzed in the form of whole blood, plasma, or serum
• Plasma - liquid portion of anticoagulated blood
• Serum- liquid portion of clotted blood
• Whole blood includes erythrocytes, leukocytes, platelets, and plasma.
• When a specimen is centrifuged, leukocytes and platelets make up the buffy coat (small white layer of cells lying between the packed red blood cells and the plasma)
• Plasma is the liquid portion of unclotted blood.
• Serum is the fluid that remains after coagulation has occurred and a clot has formed.
• Plasma is composed of 90% water and contains proteins, enzymes, hormones, lipids, and salts
• Plasma normally appears hazy and pale yellow (contains all coagulation proteins), and serum normally appears clear and straw colored (lacks fibrinogen group coagulation proteins)
• 45% of blood composed of formed elements: RBC, WBC, Platelets
• Remaining 55% is fluid composed of 90% water and 10% proteins, CHO, vitamins, hormones, enzymes, lipids and salts
• COLOR – arterial blood: bright scarlet red, venous blood: dark red
• VISCOSITY (resistance to flow) – thick and sticky fluid that normally flows with difficulty
• SPECIFIC GRAVITY – 1.055 to 1.065
• pH – 7.35 to 7.45
• Immediate inversion of this tube eight times is critical to prevent clotting and ensure accurate blood counts
• If the sample is allowed to clot, the liquid portion is called serum
• The major difference between plasma and serum is that plasma contains the protein fibrinogen and serum does not.
• COAGULATION SECTION

  Specimen: Plasma from light blue stopper tubes (sodium citrate)
• COMPLETE BLOOD COUNT (CBC)

  Most frequent Blood tests
• COMPLTE BLOOD COUNT (CBC)

  Provides a detailed information about the cells in the blood
• COMPLTE BLOOD COUNT (CBC)

  Screening test for most diseases
• COMPLTE BLOOD COUNT (CBC)

  Also called as: ✓ Full Blood Count ✓ Full Blood Exam
• COMPLTE BLOOD COUNT (CBC)

  Sample: EDTA Blood
• HEMATOCRIT DETERMINATAION

  Volume of packed red cells (VPRC)
• MICROHEMATOCRIT METHOD

  heparinized capillary tubecapillary attraction ( 75 mm /7.5cm X 1.0 or 1.2 mm)
• MICROHEMATOCRIT METHOD

  sealed with a clay (Seal ease; critoseal; critocaps, plasticine)
• MICROHEMATOCRIT METHOD

  direct reading device or with caliper
• SOURCE OF ERROR IN HEMATOCRIT COUNTS

  Excess of Anticoagulant

  • Centrifugation

  ✓ Undercentrifugation ✓ Overcentrifugation

  • Improper use of reader

  • Wash out blood

  • Bubbles/spaces in the tube
• HEMATOCRIT

  Volume of packed RBCs that occupies a given volume of whole blood
• HEMATOCRIT

  Reported: percentage(%) or L/L
• MICROHEMATOCRIT PROCEDURE:

  Fill capillary tube approximately three – quarters full with anticoagulated blood
• MICROHEMATOCRIT PROCEDURE

  Seal the end of the tube with the colored ring with clay and wax •