BLOOD TRANSFUSIONINDICATION1. Blood loss greater than 20% of blood volume when more than 100 mL2. Hemoglobin level less than 8 g/dL3. Hemoglobin level less than 10 g/dL with major disease (e.g., emphysema, ischemic heart disease)4. Hemoglobin level of less than 10 g/dL with autologous blood5. Hemoglobin level less than 12 g/dL and ventilator dependentCOMPLICATIONFEBRILE1. most common mild reaction, 0.5%-4% of transfusions2. due to alloantibodies to WBC, platelet, or other donorplasma antigens3. fever likely caused by pyrogens liberated from lysed cells4. more common if previous transfusion5. mild fever < 38 with or without rigors, fever may be > 38with restlessness and shivering6. nausea, facial flushing, headache, myalgias; hypotension,chest and back pain (less common) 7. near completion of transfusion or within 2 hours8. up to 40% with mild reactions will not experience anotherreaction with future transfusions9. with severe/recurrent reactions, future transfusions maycause leukocyte depletion Management rule out fever due to hemolytic reaction or bacterial contamination. mild < 38 - decrease infusion rate and antipyretics severe - stop transfusion, antipyretics, antihistamines,symptomatic treatmentALLERGIC1. mild allergic reaction occurs in about 3% of transfusionsdue to IgE alloantibodies vs. substances in donor plasma2. mast cells activated with histamine release3. usually occurs in pre-exposed e.g. multiple transfusions,multiparous4. often have history of similar reactions5. abrupt onset pruritic erythema / urticaria on arms andtrunk, occasionally with fever6. less common - involvement of face, larynx, and bronchiolesManagement mild - slow transfusion rate, IV antihistamines moderate to severe - stop transfusion, IVantihistamines, subcutaneous epinephrine,hydrocortisone, IV fluids, bronchodilators prophylactic - antihistamines 15-60 minutes priorto transfusion, washed or deglycerolized frozen RBCANAPHYLACTIC1. rare, potentially lethal2. in IgA deficient patients with anti-IgA antibodies3. immune complexes activate mast cells, basophils,eosinophils, and complement system= severe symptoms after transfusion of RBC, plasma,platelets, or other components with IgA4. apprehension, urticarial eruptions, dyspnea,hypotension, laryngeal and airway edema,wheezing, chest pain, shock, sudden deathmanagement circulatory support with fluids,catecholamines, bronchodilators, respiratoryassistance as indicated evaluate for IgA deficiency and anti-IgAantibodies future transfusions must be free of IgA:washed/deglycerolized RBCs free of IgA,blood from IgA deficient donor

TRANSFUSION - RELATED ACUTE LUNG INJURY(TRALI)1. form of non-cardiogenic pulmonary edema2. occurs 2-4 hours post transfusion3. immunologic cause; not due to fluid overload or cardiacfailure - is a reaction to transfusion4. respiratory distress - mild dyspnoea to severe hypoxia5. chest x-ray - consistent with acute pulmonary edema, but pulmonary artery and wedge pressures are not elevatedmanagement usually resolves within 48 hours with O2, mechanicalventilation, supportive treatmentIMMUNOSUPPRESSIONsome studies show associations between perioperative transfusion and post operative infection , earlier cancer recurrence, and pooreroutcomeImmune Hemolytic1. most serious and life threatening transfusion reaction2. caused by donor incompatibility with recipients blood3. Can be caused by as low as 10 ml of blood ACUTE- Intravascular hemolysis most severe often due to clerical error antibody coated RBC is destroyed by activation of complement systemI. ABO incompatibility common cause, other RBC Ag- Ab systems can be involvedII. fever, chills, chest or back pain, hypotension, tachycardia, nausea, flushing, dyspnoea , haemoglobinuria , diffuse bleeding due to disseminated intravascular coagulation (DIC), acute renal failure (ARF)III. in anesthetized patients, signs include hypotension, tachycardia, wheezing, hypoxemia and hemoglobinuriaManagement stop transfusion notify blood bank, confirm or rule out diagnosis-clerical check, direct Coombs test, repeat grouping, Rg screen and crossmatch , serum haptoglobin manage hypotension with fluids, inotropes, other blood product maintain urine output with crystalloids,furosemide, dopamine, alkalinize urine component treatment if DICDELAYED I. Extravascular hemolysisII. anemia, mild jaundice, fever 1-21 days posttransfusionIII. incompatibility of antigen and antibody that do notbind complementIV. Ab coated RBC destroyed by macrophagicphagocytosis by in reticuloendothelial system (RES)V. failure to recognize these antibodies at crossmatchoften involvedVI. low titre antibodies may be undetectable, butamnestic response in recipient = buildup ofantibodiesto incompatible RBC several days post transfusionVII. predisposing factors to hemolytic transfusionreactionsa. F to M = 3:1b. increasing agec. blood products administered on emergent basis

Nonimmune infectious risks HIV, hepatitis, Epstein-Barr virus(EBV), cytomegalovirus (CMV), brucellosis, malaria,salmonellosis, measles, syphilis hypervolemia electrolyte changes increased K+ in stored blood coagulopathy hypothermia citrate toxicity hypocalcemia