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99 Cards in this Set
- Front
- Back
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What is the rate of bacterial sepsis or endotoxin reaction following transfusion of RBCs?
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1 in 30,000 donor exposures
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What is the rate of bacterial sepsis or endotoxin reaction following transfusion of Platelets?
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1 in 2,000 donor exposures
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What is the rate of HBV infection per donor exposure following transfusion of blood products?
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1 in 350,000
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What is the rate of HCV infection per donor exposure following transfusion of blood products?
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1 in 2 million
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What is the rate of HIV infection per donor exposure following transfusion of blood products?
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1 in 2 million
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What is the rate of HTLV infection per donor exposure following transfusion of blood products?
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1 in 2.9 million
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What is the "window period" between infection and detectability by the available assays for HIV?
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Using nucleic acid testing, 13 days
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What is the "window period" between infection and detectability by the available assays for HCV?
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Using nucleic acid testing, 12 days
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What is the "window period" between infection and detectability by the available assays for HIV?
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Using HbsAg testing, 59 days, although there may be a nucleic acid test by 2008.
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What percent of HBV-exposed patients will develop acute disease?
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35%
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What percent of HBV-exposed patients will develop fulminant acute hepatitis?
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1%
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In what percentage of patients does HBV resolve spontaneously?
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85%
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In what percentage of patients does HBV progress to chronic persistent hepatitis?
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9%
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What is the screen for HAV and why?
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The screen is by history only because there is no carrier state for HAV and the infectious period is only 1 - 2 weeks long.
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What was the risk of HIV infection per transfusion donor exposure in the 1980s?
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1 in 100
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What was the risk of HIV infection per transfusion donor exposure in the 1997?
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1 in 400,000
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What possible transfusion infection, usually benign and self-limited in the immuno-competent, can be serious and fatal in the immunocompromised?
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CMV
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What blood product carries the most risk of malaria infection and why?
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RBCs, because that's where the parasite resides.
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What is the rate of fatality per transfused unit due to bacterial contamination?
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1 in 1 to 6 million
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Which blood product is associated with a greater risk of fatal bacterial infection and why?
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Platelets because they are stored at room temperature and involve pools of 6 to 10 units.
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What are the four most common organisms associated with platelet transfusion-related bacterial infection in order of frequency?
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1) Staph aureus [n] 2) Kleb pneumo [n] 3) Serratia marcescens [n] 4) Staph epidermidis
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What are three types of bacteria that can grow at RBC storage temperatures?
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1) Yersinia enterocolitica [n] 2) Serratia spp. [n] 3) Pseudomonas spp.
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What will a patient who receives bacteria-contaminated blood products experience?
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Rapid onset of:[n]
- Fever [n] - Chills [n] - Tachycardia [n] - Emesis [n] - Shock [n] [n] May also develop: - DIC [n] - ARF |
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Is West Nile Virus transmissible via blood transfusion?
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Yes.
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Name 5 antibodies that fix complement and produce immediate intravascular hemolysis.
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1) anti-A [n]
2) anti-B [n] 3) anti-Kell [n] 4) anti-Lewis [n] 5) anti-Duffy [n] |
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What is the incidence of acute hemolytic transfusion reactions?
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1 per 12,000 transfused units
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What percentage of patients with an acute hemolytic reaction after transfusion develop DIC?
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30 - 50%
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List four causes of renal damage in an a transfusion-related acute hemolytic reaction.
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1) reduced renal blood flow due to systemic hypotension and renal vasoconstriction [n]
2) mechanical obstruction of the renal tubules due to free hemoglobin [n] 3)deposited Ag-Ab complexes in the glomeruli [n] 4) If DIC present, fibrin thrombi will further occlude renal vasculature |
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What activates Factor XII in an acute transfusion hemolytic reaction?
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The antigen-antibody complexes
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What are the effects of bradykinin in an acute hemolytic transfusion reaction?
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Bradykinin:[n]
1) increases capillary permeability [n] 2) dilates arterioles |
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What does the activation of complement in an acute transfusion-related hemolytic reaction cause?
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Bronchospasm because complement causes mast cells to release: [n]
1) histamine [n] 2) serotonin |
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What are the first three signs of an acute hemolytic reaction if the patient is awake?
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1) sense of impending doom [n]
2) restlessness [n] 3) headache |
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During general surgery what are the three reliable clues for a hemolytic reaction?
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1) hypotension [n]
2) hemoglobinuria [n] 3) diffuse bleeding in DIC |
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What are the three main objectives of management of an acute transfusion-related hemolytic reaction?
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1) maintain blood pressure [n]
2) preserve renal function [n] 3) prevent DIC |
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What labs should be ordered if a patient has an acute transfusion-related hemolytic reaction?
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To test for immune reaction: [n]
- repeat cross-match [n] - direct antiglobulin (Coombs) test[n][n] TO ESTABLISH BASELINE COAGS:[n] - Platelet count[n] - PT/aPTT/TT/Fibrinogen level/D-dimers[n][n] TO CONFIRM HEMOLYSIS:[n] - serum haptoglobin - plasma and urine Hgb - plasma and urine bili |
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What is a simple, rapid screening test when a hemolytic transfusion reaction is suspected?
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Brief centrifugation of patient's blood to see if there is pink discoloration of plasma due to free hemoglobin.
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What are the signs and symptoms of a hemolytic transfusion reaction?
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Impending sense of doom [n]
Headache [n] Restlessness [n] Fever [n] Chills [n] Nausea [n] Vomiting [n] Diarrhea [n] Rigors [n] Chest and Back pain[n] Hypotension and Tachycardia (bradykinin release) [n] Flushed and Dyspneic (histamine release) [n] Excessive bleeding [n] |
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What actions should be taken to promote urine output in an acute hemolytic reaction?
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- administration of fluids [n]
- mannitol and/or furosemide [n] - sodium bicarb to alkalinize urine |
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What are other (more benign) causes of hemolysis that should be considered in the setting of an acute transfusion-related hemolytic reaction?
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- overheating the transfusion [n]
- use of hypotonic solution as diluent |
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What is the frequency of delayed hemolytic reactions?
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1 in 800 to 2500 transfusions
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What antibodies are often involved in a delayed hemolytic reaction?
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- Rhesus [n]
- Kell [n] - Duffy [n] - Kidd |
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Where does red cell destruction occur in a delayed hemolytic transfusion reaction?
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Extravascularly because the antibody-coated RBC has been sequestered. So it would occur in the spleen or reticuloendothelial system.
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When and how might evidence of a delayed hemolytic transfusion reaction appear?
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- days to two weeks after transfusion [n]
- often undetected [n] BUT MAY HAVE:[n] - low-grade fever [n] - increased bili w/wo jaundice [n] - unexplained reduction in Hgb concentration |
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How would you confirm and treat a suspected delayed transfusion-related hemolytic reaction?
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- Coombs test (direct antiglobulin test) will be positive [n]
- Haptoglobin should be decreased [n] - treatment not usually necessary as reaction is self-limiting and signs and symptoms resolve with removal of transfused cells |
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What percentage of transfusions result in urticarial reactions?
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0.5%, almost always associated with FFP
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If a patient has a history of severe urticarial reaction with transfusions, how might this be avoided in future transfusions?
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Use saline washed cells
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What patient-population is at risk for anaphylaxis after transfusion?
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Patients with hereditary IgA deficiency sensitized against "foreign" IgA by previous transfusion or pregnancy.
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If a patient is known to have hereditary IgA deficiency and needs transfusion, what precautions might you take and why?
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This patient is at risk for an anaphylactic reaction if sensitized against foreign IgA. [n]
Use:[n] - washed red cells [n] - frozen deglycerolized red cells [n] - or red-cells from IgA-deficient donors |
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What are the symptoms of an anaphylactic reaction?
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- dyspnea [n]
- bronchospasm [n] - hypotension [n] - laryngeal edema [n] - chest pain [n] - shock |
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What is the treatment of a transfusion-related anaphylactic reaction?
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- d/c transfusion [n]
- epinephrine [n] - methylprednisolone |
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What are the White Cell-Related Transfusion Reactions?
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- Febrile reactions [n]
- TRALI [n] - GVHD [n] - Immunomodulation [n] |
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What are the Transfusion-related reactions to RBC antigens?
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- Acute Hemolytic Transfusion Reaction [n]
- Delayed Hemolytic Transfusion Reaction |
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Describe the natural history of a simple febrile reaction to transfusion.
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-increase of more than 1 degree centigrade within 4 hours of a blood transfusion [n]
-defervesces within 48 hours |
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Describe the signs and symptoms of a simple febrile reaction to transfusion.
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-increase of more than 1 degree C w/in four hrs of transfusion [n]
-sometimes only fever but may also include: [n] -chills [n] -respiratory distress [n] -anxiety [n] -headache [n] -myalgias [n] -nausea [n] -non-productive cough |
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How does one treat a simple febrile reaction to transfusion?
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-Acetaminophen [n] (be sure to have ruled out a hemolytic reaction using the Coombs test)
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What percentage of RBC transfusions cause a febrile reaction?
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1%
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What can reduce the incidence of post-transfusion febrile reactions?
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Leukoreduction
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What is TRALI?
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Transfusion-Related Acute Lung Injury is a noncardiogenic form of pulmonary edema associated with blood product administration.
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What blood components is TRALI associated with?
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All blood components, but most fequently RBCs, FFP, and platelets.
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What is the incidence of TRALI?
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1 per 5,000 transfused units although it is thought that this is a gross underestimation due to failure of recognition and reporting of incidences.
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What is the mortality of TRALI (percentage of people with TRALI who die)?
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5% to 8%
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Describe the natural history of TRALI.
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Within 6 hours of transfusion and often more rapidly patient develops: [n]
- dyspnea [n] - noncardiogenic pulm edema [n] - chills [n] - fever [n] - may develop severe pulmonary insufficiency |
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What is thought to be the cause of the pulmonary insult in TRALI?
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It is thought that TRALI is most often caused by anti-leukocyte Ab from a DONOR sensitized by pregnancy or previous transfusion. [n] [n]
The converse is also possible if the RECIPIENT has been alloimmunized against WBC antigens. [n] [n] Finally, TRALI does not always have antigranulocytic antibodies present and so it is thought that BIOLOGICALLY ACTIVE LIPIDS from the transfusion can initiate TRALI. |
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What would a chest x-ray show in TRALI?
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bilateral infiltrates
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What is the treatment of TRALI?
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largely supportive [n]
- d/c transfusion [n] - supplemental O2 [n] - ventilatory support if needed using same low tidal volume strategies as ARDS[n] - in the future use washed PRBCs |
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What group of transfusion DONORs have been identified as frequent sources of antileukocyte antibodies?
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Multiparous females
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What patients are at risk for GVHD after transfusion?
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1) organ transplant recipients [n]
2) neonates s/p blood-exchange transfusion [n] 3) any immunocompromised patient [n] 4) immunoCOMPETENT patients with a genetic relationship to the donor |
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Why might an immunocompetent patient develop GVHD after receiving a transfusion from a relative?
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If a recipient shares HLA antigen haplotypes, the recipient may fail to reject the donor lymphocytes, (i.e. not recognize them as foreign). The foreign lymphocytes on the other hand, may engraft and recognize the recipient as foreign. As a result, donations from first-degree relatives should be irradiated to inactivate donor lymphocytes.
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What is the only effective means for preventing transfusion-related GVHD?
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irradiation of the blood products
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What are the confirmed benefits of leukoreduction of blood products?
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1) Decreased alloimmunization and platelet refractoriness in multiply-transfused leukemics [n]
2) prevention of febrile reactions to RBC transfusions [n] 3) Reduction of CMV transmission |
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What are the reported but unconfirmed benefits of leukoreduction?
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1) decreased postop infections [n]
2) decreased postop mortality [n] 3) shortened hospitalization [n] 4) Prevention of transfusion-related HIV acceleration [n] 5) prevention of transfusion-related increase in tumor recurrence [n] 6) reduced incidence severity of GVHD |
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What effect does transfusion of non-leukoreduced blood products have on the immune system?
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It is thought to weaken the immune system
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What is a possible effect on blood pressure in patients receiving bedside filtered blood?
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hypotension caused by bradykinin. ACEi may increase the risk since they reduce the breakdown of bradykinin.
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By how much will the administration of one unit PRBCs at 4 degress centigrade reduce the core temperature of a 70-kg man?
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0.25 degrees Celsius
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What effect does hypothermia have on coagulation? platelets?
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Hypothermia slows coagulation and sequesters platelets.
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At what hypothermic temperature is the risk of cardiac dysrhythmia critical?
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29 degrees Celsius
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There is a temperature at which the risk of cardiac dysrhythmia becomes critical. What are the PT, aPTT, and platelet values at this temperature?
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At 29 degrees Celsius, PT & aPTT will increase approximately 50% over normothermic patients. [n] Platelets will decrease by about 40%.
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What are the common clinical concomitants of hypothermia?
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- shock [n]
- acidosis [n] - massive transfusion [n] - massive tissue injury [n] |
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What are the non-infectious risks associated with massive transfusion?
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- hypothermia [n]
- volume overload [n] - dilutional coagulopathy [n] - decreased 2,3-Diphosphoglycerate [n] - Acid-Base changes [n] - Hyperkalemia [n] - Citrate Intoxication [n] - Microaggregate Delivery [n] |
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Shivering on emergence of anesthesia can increase oxygen consumption by what percentage?
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400%
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In a patient receiving a large-volume isovolemic transfusion, at what percent of volume exchange would you expect a clinically significant dilution of fibrinogen?
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140%
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In a patient receiving a large-volume isovolemic transfusion, at what percent of volume exchange would you expect a clinically significant dilution of factors II, V, and VIII?
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200% - 230%
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In a patient receiving a large-volume isovolemic transfusion, at what percent of volume exchange would you expect a clinically significant dilution of platelets?
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230%
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Why might transfuion result in less efficient oxygen delivery than would occur with native hemoglobin at the same hematocrit?
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Because storage of RBCs results in decrease of ATP and 2,3-DPG with a resultant let shift of the O2-Hgb dissociation curve.
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How long does it it take 2,3-DPG levels to return to normal after transfusion?
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12 - 24 hours
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After 21 days of storage, what might the pH of a unit of pRBCs be?
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6.9
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When CPD solution is added to freshly drawn blood, how does it affect the pH?
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It decreases to 7.0 - 7.1
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What transfusion rates have been associated with hyperkalemia?
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Rates in excess of 90 - 120 mL/min
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How many mL of plasma are in a unit of packed RBCs?
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20 - 60mL
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Most of the citrate administered during massive transfusion comes from what blood product?
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FFPs, not pRBCs
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Citrate intoxication causes which first: cardiac complications or coagulation problems?
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cardiac complications due to the hypocalcemia
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Decreased ionized calcium levels will be caused when the rate of transfusion exceeds ______.
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1mL/kg/min or about 1 unit of blood per 5 minutes.
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Citrate addition to blood products anticoagulates by what mechanism?
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Chelating ionized calcium
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What type of aggregates form in stored blood after 2 to 5 days?
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Platelet aggregates.
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What type of aggregates form in stored blood after 10 days?
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Platelet aggregates will have already formed. At day 10 larger ones composed of fibrin, degenerated white cells and platelets appear. As well as macroaggregates of RBCs.
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Large volume transfusions are defined as what?
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More than 10 - 12 units in 24 hours.
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Microaggregates in transfusions have been implicated in the pathogenesis of what?
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pulmonary insufficiency and ARDS which often follows large volume transfusions, although studies have not teased out the independent contribution.
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Why is NS recommended over LR for dilution of RBCs during transfusion?
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Because the citrate present in stored blood is more than sufficient to bind the calcium in the 100 - 300cc of LR used for dilution.
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Is there any evidence that use of LR as an RBC diluent has resulted in clinically significant sequelae?
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No.
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