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Blood and Blood Component Therapy. Dr Andrea Yu Department of Anesthesia and Intensive Care. Basic Knowledge …. Components of blood Functions of blood and blood components Blood groups Screening of pathogens in blood. Topics to be covered …. Blood grouping and cross-matching
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Blood and Blood Component Therapy Dr Andrea Yu Department of Anesthesia and Intensive Care
Basic Knowledge … • Components of blood • Functions of blood and blood components • Blood groups • Screening of pathogens in blood
Topics to be covered … • Blood grouping and cross-matching • Blood component therapy • Complications of blood transfusion • Methods to reduce blood transfusion • Case Scenarios
Blood Group Systems • ABO system • Rhesus system • Other blood groups • MN • Lutheran • Kell • Duffy • Kidd
ABO Blood Groups • anti-A and anti-B are naturally occurring IgM
Rhesus system • Many types of Rhesus antigen identified • RhD Ag is the most antigenic • Rh positive • RBC having D antigen • Rh negative • RBC without D antigen • Anti RhD Ab are IgG
Compatibility testing • Major complications • incompatibility between donor’s red cells and antibodies in recipient’s plasma • Three procedures • Blood typing • Antibody screen • Cross-match
Blood grouping • RBC • Test with anti-A and anti-B Ab • Test with anti-D Ab • Serum • Test with A and B RBC
Antibody Screening • Recipient’s serum + commercially supplied RBCs • Indirect antiglobulin test
Cross-matching • Recipient’s serum + donor’s RBCs • At room temp • Incubate at 37C • Antiglobulin serum • Detect incomplete antibodies
ABO Rh typing ABO Rh typing + Ab screen Crossmatch Compatible transfusion 99.8% 99.94% 99.95% Is Crossmatch Really Necessary?
Blood Component Therapy Whole blood/packed red cells
Function of Blood • Intravascular volume • Oxygen carrying capacity • DO2= Cardiac Output (CO) x Oxygen Content (CaO2) • Oxygen Content (CaO2): - (Hgb x 1.39) x O2 saturation + PaO2(0.003)
Tolerance of blood loss • Maintenance of intravascular volume • Ability to increase cardiac output • Age, co-morbidities • Increase in oxygen delivery by 2,3-DPG • Acute/chronic, rate of loss of blood
Principle of fluid therapy • Replenish intravascular volume • Crystalloids : NS, LR (3:1 ratio) • Colloids: gelofusin, haemacel, hetastarch • Restore oxygen carrying capacity
Transfusion trigger • Hb level at which transfusion is necessary • ? 10g/dL • ? 8g/dL • ? 6g/dL • ? 4g/dL
Restrictive transfusion • Hb 7-9 g/dL • Liberal transfusion • Hb 10-12 g/dL • 30-day mortality • 18.7 % vs 23.3% (P= 0.11) • significant cardiac disease 20.5% vs 22.9% (P=0.69) NEJM 340(6):409-417
Hb >10g/dL • Generally not required transfusion • Hb 7-10g/dL • Consider acute/chronic blood loss, ongoing blood loss • Age, cardiorespiratory status, intravascular volume • Risks of transfusion • Hb < 7g/dL • Usually required transfusion • Hb < 5g/dL • Transfusion essential
How much to give? • Packed cells • 4-5ml/kg to raise Hb 1g/dL • Whole blood • 8-10ml/kg to raise Hb 1g/dL • Complete transfusion in 4 hours
Blood Component Therapy FFP, platelets, cryoprecipitate
FFP • Separated and frozen within 18hrs after collection of whole blood • Contains all coagulation factors • Including labile factors V & VIII • Volume: 200-250 ml • Shelf life: 12 months at -25°C • ABO compatibility essential
Indication for FFP transfusion • Urgent reversal of warfarin effect • DIC with bleeding • Microvascular bleeding in the presence of elevated (>1.5 times normal) PT or APTT • Coagulopathy after massive transfusion • Coagulation factor deficiency (when specific concentrates are unavailable)
Dose: 10-15ml/kg • Thawed before administration • Once thawed • Infuse immediately, or • Stored at 2-6°C for up to 24 hours • Complete infusion in 4 hours
Platelet Concentrates • Platelets separated from a single unit of whole blood • suspended in a small amount of the original plasma • Volume: 40-60ml • Shelf life: 5 days at 20-24°C • Agitated gently and continously on a platelet shaker during storage • ABO compatible platelets preferable
Indications for Platelet Tranfusion • actively bleeding • Platelet count <20,000/mm3 • Platelet count <50,000/mm3 in the setting of additional risk factors (sepsis, concurrent antibiotic use, uraemia)
absence of active bleeding: • Platelet count <5,000/mm3 • Platelet count <20,000/mm3 + a high risk of bleeding or in children undergoing a lumbar puncture • Platelet count <50,000/mm3 in a patient to undergo any invasive procedure • Platelet count <100,000/mm3 if procedure involves the CNS or eye
prophylactic platelet transfusion is ineffective and not indicated • ITP • TTP • Heparin-induced thrombocytopenia • Use only when these are assoicated with haemorrhage
1 unit of platelets increases platelet count 5000-10000 mm3 in 70kg adult • 1 unit / 10kg BW • Complete transfusion in 4 hours
Cryoprecipitate • Prepared by: • Thawing fresh frozen plasma between 1-6°C • Recovery the precipitate • The precipitate is then refrozen • Factor VIII, Factor XIII, vwF, fibrinogen and fibronectin • Volume: 10-40ml • Shelf life: 12 months at -25°C • ABO compatibility preferred
Indications for Cryoprecipitate Transfusion • Bleeding due to hypofibrinogenemia or dysfibrinogenemia • DIC with fibrinogen and FVIII depletion • Prophylaxis or treatment of significant FXIII deficiency • 1-1.5u / 10kg BW
Safe Administration of Blood • Correct patient identity • Blood taking • Blood processing • Before transfusion • Check the package • Correct method of storage
Administration of Blood Products • 170-260 m filter
0.9% NaCl can be infused with blood • Most other commonly used solutions are not compatible with blood • D5 • Haemolysis due to hypontonicity • Lactated ringers/Haemaccel • Calcium leads to clotting
Infections • Bacterial contamination • CMV, Hepatitis B, Hepatitis C, HIV, HTLV • Malaria • Syphilis • Human Parvovirus B19 • ? vCJD
Immune-mediated Complications • Acute hemolytic reaction • 1:12,000-77,000 • ABO incompatibility, mediated by IgM • Fever, chills, SOB, hemolysis, hemoglobinuria, MODS, DIC, death • Mx • Stop further transfusion • Send the remaining blood to blood bank • CBP, RFT, clotting, LDH, haptoglobin, urine Mb • Organ support – BP, renal blood flow, rx of DIC, coagulopathy
Delayed hemolytic reaction • 1:4,000-9,000 • Previously sensitized patients with low IgG titre • Rh and Kidd systems • Hemolysis a few days after blood transfusion • Mx: • Type and screen • Transfusion with compatible blood
Febrile non hemolytic transfusion reactions (FNHTR) • 1:100 • IgG against donor WCC and platelets • Fever, chills • Mx • Rule out Acute hemolytic reactions • Anti-pyretics • Use leukocyte-reduced blood products
Allergic reactions • Very common, 1-3% of plasma transfusion • Donor plasma proteins react with recipient’s mast cells • Urticaria, itching, laryngeal edema • Mx • Rule out anaphylaxis • Anti-histamine, +/- steroid • Saline–washed RBCs, slower infusion rate
Anaphylaxis • Congenital IgA deficiency, high titre of IgG to IgA • Urticaria, bronchospasm, hypotension • Mx: • ABC, organ support • Adrenaline, steroid, organ support
Transfusion-related acute lung injury • 1:5000 – 1:10000 plasma containing blood products • Donor anti-leucocyte Ab reacts with recipient WCC in pulmonary vasculature • Acute respiratory distress < 6 hours after transfusion • Hypoxemia, bilateral lung infiltrates, hypotension, fever • 80% improve rapidly within 48h, 5-10% mortality • Mx • Organ support
TAGvHD • transfused immunocompetent lymphocytes directed against an immunocompromised host • Mx • Irradiated RBC and platelets • Immunomodulatory effect • Increase risk of recurrence of cancers • Increase risk of post-operative infection
Alloimmunisation • Blood products exposes patient to: • Red cells • White cells • Platelet antigens • Plasma proteins • Patients may develop antibodies in response to foreign antigen exposure
Metabolic Complications • Fluid overload • Citrate toxicity • Metabolic acidosis • Hyperkalemia, hypocalcemia • Hypothermia • Impaired O2 delivery • Dilutional coagulopathy, thromocytopenia