Indications and complications of blood transfusion
INDICATIONS AND COMPLICATIONS OFBLOOD TRANSFUSION Presenter : Abhimanyu Ganguly Resource Faculty : Dr Krishna Pokhrel
What is the need for blood transfusion?Blood transfusions are given to:• increase oxygen-carrying capacity• increase intravascular volume.(role of fluids?)
Transfusion Triggers-Used for the different factors that are to beconsidered as important markers indicating the needfor blood transfusion-Chiefly Hb% and Hct. are used but even thesecannot be taken as absolute.
American Society of Anesthesiologists Practice Guidelines• 1. Transfusion is rarely indicated when the hemoglobin concentration is greater than 10 g/dL and is almost always indicated when it is less than 6 g/dL, especially when the anemia is acute.• 2. The determination of whether intermediate hemoglobin concentrations (6 to 10 g/dL) justify or require RBC transfusion should be based on the patients risk for complications of inadequate oxygenation and the evaluation of the attending doctor.
• 3. The use of a single hemoglobin "trigger" for all patients and other approaches that fail to consider all important physiologic and surgical factors affecting oxygenation is not recommended.• 4. When appropriate, preoperative autologous blood donation, intraoperative and postoperative blood recovery, acute normovolemic hemodilution, and measures to decrease blood loss (i.e., deliberate hypotension and pharmacologic agents) may be beneficial.• 5. The indications for transfusion of autologous RBCs may be more liberal than those for allogeneic RBCs because of less frequent (but still significant) risks associated with the former.
Indications1. Blood loss greater than 20% of blood volume when more than 100 mL1. Hemoglobin level less than 8 g/dL1. Hemoglobin level less than 10 g/dL with major disease (e.g., emphysema, ischemic heart disease)1. Hemoglobin level of less than 10 g/dL with autologous blood1. Hemoglobin level less than 12 g/dL and ventilator dependent
BLOOD PRODUCTS Red Blood Cells: RBC’s (U = Unit)❏ 1 U PRBCs = +/– 300 mL1 U PRBCs increases hemoglobin (Hb) by approx 10 g/L in a 70 kg patient❏ PRBCs may be diluted with colloid/crystalloid todecrease viscosity❏ decision to transfuse is based on initial bloodvolume, premorbid Hb level , present volume status,expected further blood loss, patient health status❏ MASSIVE transfusion > 1 x blood volume/24 hours
Autologous RBCs❏ replacement of blood volume with ones ownRBCs❏ marked decrease in complications (infectious,febrile, etc.)❏ alternative to homologous transfusion in electiveprocedures, but only if adequate Hb, and noinfection❏ pre-op phlebotomy with hemodilution prior toelective surgery (up to 4 U collected > 2 days beforesurgery)❏ intraoperative salvage and filtration (cell saver)
Complications associated with autologousblood transfusions1. Anemia2. preoperative myocardial ischemia from anemia3. administration of wrong unit(1:100000)4. need for more frequent transfusions5. febrile and allergic reactions
COMPLICATIONS•Changes in Oxygen Transport•Coagulation•Dilutional Thrombocytopenia• Low Levels of Factors V and VIII•Disseminated Intravascular Coagulation-like Syndrome•Hemolytic Transfusion Reaction•Citrate Intoxication and Hyperkalemia•Temperature•Acid-Base Abnormalities
Non-RBC Products❏ FFP (fresh frozen plasma)•10-15 mL/kg•to prevent/treat bleeding due to coagulation factordepletion•for liver failure, factor deficiencies, massive transfusions•contains all plasma clotting factors and fibrinogen close tonormal plasma levels❏ factors•cryoprecipitate (1 U/7-10 kg) or preps (von WillebrandFactor (VWF), factor VIII, etc.)
❏ platelets•1 concentrate/10 kg•thrombocytopenia, massive transfusions, impaired plateletfunction❏ albumin•selective intravascular volume expander❏ erythropoietin•can be used preoperatively to stimulate erythropoiesis❏ pentaspan•colloid, don’t give > 2 L/70 kg/24 hours
Massive blood transfusion• Defn :• Transfusion of blood more than patient’s blood volume (5 ltrs.) in less than24 hrs.• OR• Transfusion of more than 10% f patients blood volume in less than 10 minutes.
Complications• Hyperkalemia• Hypocalcemia• Hyperammonemia• Hypothermia• Metabolic alkalosis(1citrate=3bicarbonate)• Dilutional coagulopathies and DIC(most worrisome and most common cause of death)• ARDS
TRANSFUSION REACTIONSImmune - Nonhemolytic 4.FEBRILE•most common mild reaction, 0.5%-4% of transfusions•due to alloantibodies to WBC, platelet, or other donorplasma antigens•fever likely caused by pyrogens liberated from lysed cells•more common if previous transfusion•mild fever < 38º with or without rigors, fever may be > 38ºwith restlessness and shivering•nausea, facial flushing, headache, myalgias; hypotension,chest and back pain (less common)
•near completion of transfusion or within 2 hours•up to 40% with mild reactions will not experience anotherreaction with future transfusions•with severe/recurrent reactions, future transfusions maycause leukocyte depletion ❏ management•rule out fever due to hemolytic reaction or bacterialcontamination.•mild < 38º - decrease infusion rate and antipyretics•severe - stop transfusion, antipyretics, antihistamines,symptomatic treatment
2. ALLERGIC• mild allergic reaction occurs in about 3% of transfusionsdue to IgE alloantibodies vs. substances in donor plasma•mast cells activated with histamine release•usually occurs in pre-exposed e.g. multiple transfusions,multiparous•often have history of similar reactions•abrupt onset pruritic erythema / urticaria on arms andtrunk, occasionally with fever•less common - involvement of face, larynx, and bronchioles
❏ management•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 RBC
3. ANAPHYLACTIC•rare, potentially lethal•in IgA deficient patients with anti-IgA antibodies•immune complexes activate mast cells, basophils,eosinophils, and complement system= severe symptoms after transfusion of RBC, plasma,platelets, or other components with IgA•apprehension, urticarial eruptions, dyspnea,hypotension, laryngeal and airway edema,wheezing, chest pain, shock, sudden death
❏ management•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
4. TRANSFUSION - RELATED ACUTE LUNG INJURY(TRALI)•form of non-cardiogenic pulmonary edema•occurs 2-4 hours post transfusion•immunologic cause; not due to fluid overload or cardiacfailure - is a reaction to transfusion•respiratory distress - mild dyspnoea to severe hypoxia•chest x-ray - consistent with acute pulmonary edema, butpulmonary artery and wedge pressures are not elevated ❏ management•usually resolves within 48 hours with O2, mechanicalventilation, supportive treatment
5. IMMUNOSUPPRESSION•some studies show associations betweenperioperative transfusion and postoperativeinfection , earlier cancer recurrence, and pooreroutcome
Immune – Hemolytic❏ most serious and life threatening transfusion reaction❏ caused by donor incompatibility with recipients’ bloodCan be caused by as low as 10 ml of blood 1.ACUTE- Intravascular hemolysis • most severe • often due to clerical error • antibody coated RBC is destroyed by activation of complement system
• ABO incompatibility common cause, other RBC Ag- Ab systems can be involved• fever, chills, chest or back pain, hypotension, tachycardia, nausea, flushing, dyspnoea , haemoglobinuria , diffuse bleeding due to disseminated intravascular coagulation (DIC), acute renal failure (ARF)• in anesthetized patients, signs include hypotension, tachycardia, wheezing, hypoxemia and hemoglobinuria
2. DELAYED –Extravascular hemolysis•anemia, mild jaundice, fever 1-21 days posttransfusion•incompatibility of antigen and antibody that do notbind complement•Ab coated RBC destroyed by macrophagicphagocytosis by in reticuloendothelial system (RES)•failure to recognize these antibodies at crossmatchoften involved
•low titre antibodies may be undetectable, butamnestic response in recipient = buildup ofantibodiesto incompatible RBC several days post transfusion❏ predisposing factors to hemolytic transfusionreactions•F to M = 3:1•increasing age•blood products administered on emergent basis
KEY POINTS1. The three most common causes of transfusion-induceddeath are bacterial contamination, transfusion-relatedacute lung injury, and mistransfusion (i.e., ABO mismatch).2. Although the overall condition of the patient is ofprime importance, a transfusion trigger of a hemoglobinlevel of 8 g/dL or less can be tolerated by patients who arenot critically ill or do not have severe cardiorespiratorydisease.
3. Because of storage at room temperature, platelets arethe blood component most frequently contaminated withbacteria4. Human and bovine modified hemoglobin products areundergoing clinical trials as synthetic blood or oxygencarriers, similar to allogeneic blood.
REFERENCES•Miller’s Anesthesia (6th edition)•Perioperative Transfusion Medicine (2nd edition)