Transfusion Emergencies

TRANSFUSION REACTIONS IMMUNOLOGIC NON-IMMUNOLOGIC

IMMUNOLOGIC TRANSFUSION REACTIONS Hemolytic reactions due to RBC incompatibility Febrile & pulmonary rxs due to WBC or plt Ags Allergic & anaphylactic rxs due to Abs against soluble Ags, usually plasma proteins Graft-vs-host dz due to transfused lymphocytes Post-transfusion purpura

NON-IMMUNE TRANSFUSION REACTIONS Volume overload Metabolic - Hyperkalemia, Hypocalcemia Hypothermia, especially in elderly, neonates Coagulopathy due to dilutional effects Rx to contaminating infectious agents

HEMOLYTIC TRANSFUSION REACTIONS Immediate intravascular hemolytic Tx reactions Delayed hemolytic transfusion reactions

INTRAVASCULAR HEMOLYTIC TX RXS Usually due to ABO incompatibility IgM complement-binding antibodies Ab to Jka, K, Fya, Rh can cause IHTR Lysis of transfused RBCs is usual scenario Rarely, lysis of recipient RBCx due to Tx of plasma containing antibodies (anti-A1)

Signs & Symptoms of IHTR Abrupt onset Fever with or without chills Chest or back pain Anxiety and Dyspnea Tachycardia and hypotension shock Intravascular coagulation Hemoglobinuria & Acute Renal Failure

If you suspect IHTR : IMMEDIATELY stop the transfusion IHTR severity related to volume of RBCs given 30 ml of incompatible RBCs may be lethal Most severe IHTR caused by > 200 ml RBCs Mortality rate for severe IHTR is 40%

Management of IHTR Notify BB, send blood bag & pt blood samples Hydration- maintain BP, urine 100ml/hr Furosemide or mannitol to maintain urine flow Assess & treat for coagulopathy Monitor renal function

Delayed Hemolytic Transfusion Rx Usually milder than IHTR Predominantly extravascular hemolysis Occurs 2-10 days post-transfusion Major causes: Abs to Jka, Rh (E, c, D) Less commonly, Abs to K, Fya % pts have > allo-antibody

Management of Delayed HTR Notify BB, send requested blood samples Maintain hydration Once Ab is known, pt needs card identifying the presence of the specific allo-antibody

Signs & Symtoms of Delayed HTR Fever Abrupt drop in hemoglobin Jaundice Can have hemoglobinuria & hemoglobinemia

Febrile, non-hemolytic Tx Rxs More common in multiply transfused pts Occurs in 0.5% - 3% of transfusions Due to Alloimmunization to WBC & plt Ags Can be due to cytokines (usually develop in platelet concentrates, in-vitro) Can be due to Tx of bacteria, bacterial toxins

Signs & Symtoms - Febrile Tx Rxs Chill, followed by fever, during or soon after Tx Headache Malaise Sometimes, with urticaria Usually mild Resolve within a few hours

Management of Febrile Tx Rxs Stop the transfusion Notify BB & send requested samples Consider the possibility of a hemolytic tx rx Evaluate for sepsis Meperidine for rigors, acetaminophen & HC Antihistamines, if urticaria Prevention - leukopoor blood after 2 febrile tx rx

Transfusion-Related Acute Lung Injury Acute onset respiratory distress Due to Tx of plasma with Abs against recipient granulocyte-specific or HLA Ags Agglutination of granulocytes & complement activation in lung vasculature Capillary leak syndrome, resembles ARDS Occurs 1 in 5000 transfusions

Transfusion-Related Lung Injury Occurs within a few hours of transfusion Chills, fever, chest pain, sometimes hypotension CXR shows florid pulmonary edema Subsides in hours, with supportive care Respiratory support for hypoxia ( O2, ventilator) High doses of corticosteroids can be helpful Hemodynamic monitoring may be needed

Allergic Reactions to Plasma Occurs in 1-3% of transfusions Mild urticaria, other types of rash Can see bronchospasm, angioedema Anaphylaxis - very rare Related to dose of plasma infused anti-IgA in IgA-deficient pts (1/400-1/500 nl people are IgA def, 20-25% have a-IgA)

Post-Transfusion Purpura Severe thrombocytopenia 5-10 days post-Tx Alloantibodies against plt-specific antigens Usually anti-HPA-1a Occurs in pts sensitized by prior Tx, pregnancy Rx with IVIG, Plasma Exchange, Steroids