SM_256b: Blood Transfusions - Compatibility / Complications Flashcards
Blood group is ____
Blood group is genetically defined blood cell surface proteins or carbohydrates to which people make antibodies
- Each blood group has its own gene or set of related genes
- 30 RBC blood groups are defined
- Carbohydrate blood groups: genes make the transferase enzymes which connect sugars together
- Protein blood groups: genes make the proteins
Describe RBC compatibility testing
RBC compatibility testing
- ABO compatability: patient and donor ABO typings
- Rh D compatability: patient and donor D typings
- Screen antibodies to non-ABO blood group antigens: to see if patient alloimmunized to RBC antigens from prior transfusion or pregnancy
- Crossmatch: crossmatch with selected RBC donor unit, determine if the RBC unit is compatible with patient
Describe manual ABO typing
Manual ABO typing
- Anti-A and anti-B
- AB: both antisera agglutinate
- O: neither aggultinate
Describe ABO blood types and antigens
ABO blood types and antigens
- O: no A or B
- A: trisaccharide
- B: trisaccharide
- AB: both A and B trisaccharides
Antibodies: IgM and IgG anti-A and anti-B, A or B antigens not present on self, naturally occurring beginning in infancy
Describe Rh D
Rh D
- D- people develop anti-D when exposed to D+ RBCs: most D- pople have no Rh D protein
- Pregnancy: D+ fetal RBCs into D- mother -> maternal anti-D can cause severe hemolysis
- Rh Ig (passive anti-D) prevents immune anti-D after small amounts of D+ RBCs
In a transfusion, give ___ RBCs to D- patients
In a transfusion, give D- RBCs to D- patients
Patients can develop ____ after RBC exposure
Patients can develop hemolytic RBC alloantibodies after RBC exposure
- Pregnancy or transfusion
Describe RBC antibody screening
RBC antibody screening
- Antibody detects non-ABO RBC antibodies
- If screen is reactive, more reagent RBCs are used to identify antibodies
- Hemolytic (usually IgG) antibodies in 1-2% of patients
Describe RBC crossmatching to verify compatability of selected unit
RBC crossmatching to verify compatability of selected unit
- Serological: patient has past or current hemolytic RBC antibodies, select units negative for target antigen and test patient plasma vs donor RBCs
- Electronic: if patient does not have past or current hemolytic antibodies, type patient twice to verify and computer verification of ABO/Rh compatability
Direct antibody test tests RBCs directly for ____ or ____
Direct antibody test tests RBCs directly for IgG or C3
On direct antiglobulin test, IgG presence appears as ___
On direct antiglobulin test, IgG presence appears as warm autoantibody or transfusion reaction to transfused RBCs
On direct antiglobulin test, C3 presence appears as ___
On direct antiglobulin test, C3 presence appears as cold agglutinin and some warm autoantibodies
Describe RBC compatability testing terms
RBC compatability testing terms
- Type and screen: patient ABO/Rh and antibody screen
- Negative antibody screen: emergency RBCs safe
- Positive antibody screen: identify antibody
- Type and cross: patient ABO/Rh and antibody screen, crossmatch desired number of RBCs
If RBCs are medically necessary before compatability testing is done, use ___
If RBCs are medically necessary before compatability testing is done, use Group O RBCs
- Rh- if girl or woman of childbearing age
- Risk: non-ABO alloantibodies
Describe what to do when you get a lab specimen and when delivering blood
Lab specimen and when delivering blood
- Avoid blood or labeling mixups
- Check patient identity using wristband in hospital
- Label all specimens immediately after collection before leaving the patient: have pre-printed labels ready but not on tubes yet
- Blood transfusion is a time-out procedure: check correct patient and unit, two people check patient and unit at bedside, electronic bedside verification
Describe symptoms of a transfusion reaction
Transfusion reaction symptoms
- Fever, chills, rigors
- Hypotension, hypertension
- Rash, itching
- Respiratory: dyspnea, wheezing, throat swelling
Stop transfusion, maintain IV line, notify blood bank, send lab testing
If dermal allergic reaction (rash, hives, itching) notify blood bank, give anti-histamines, and restart unit carefully
Common transfusion reactions are ____, ____, and ____
Common transfusion reactions are allergic, febrile, and transfusion-associated circulatory overload
Describe presentation of allergic transfusion reactions
Allergic transfusion reactions
- Dermal: itching, hives, rash, facial swelling
- Airway: wheezing dyspnea
Allergic transfusion reactions result from ___
Allergic transfusion reactions result from IgE antibodies to allergens in plasma
- Especially plasma-rich components such as plasma and platelets
Allergic transfusion reactions are treated with ___
Allergic transfusion reactions are treated with antihistamines (also prophylactic pre-transfusion)
- Severe: epi, corticosteroids
- Usually donor-specific, not recurrent
- If recurrent or severe: washed RBCs or plasma-reduced platelets
Febrile non-hemolytic transfusion reactions present with ____, ____, or ____
Febrile non-hemolytic transfusion reactions present with fevers, chills, or rigors
- Usually donor-specific, not recurrent
- If recurrent: leukoreduced RBCs and platelets
Febrile non-hemolytic transfusion reactions result from ____
Febrile non-hemolytic transfusion reactions result from patient antibodies to donor WBCs in blood bag
- Cytokines from donor WBCs generated during storage
- Treat: antipyretics (acetaminophen)
Transfusion-associated circulatory overload presents with ___, ___, ___, and ___
Transfusion-associated circulatory overload presents with dyspnea, hypoxia, pulmonary edema, and cardiac injury
Transfusion-associated circulatory overload results from ___
Transfusion-associated circulatory overload results from RBC / plasma in tranfusion expanding the intravascular volume
- Treat with diuresis
- Prevent by assessing volume status pre-transfusion
Describe serious transfusion reactions
Serious transfusion reactions
- Transfusion-associated circulatory overload
- Acute hemolytic
- Transfusion-related acute lung injury
- Septic
- Anaphylactic
- Transfusion-associated graft-vs-host disease
Extravascular hemolysis is ____ and involves ____ and then ____
Extravascular hemolysis varies in speed and involves IgG antibody binding to RBC and then phagocytosis of RBC
- IgG binds to Fc receptors on phagocytes (especially in spleen)
- Antibody activates complement
Intravascular hemolysis is ___ and involves ___ and then ___
Intravascular hemolysis is rapid and involves IgM or IgG antibody binding to RBC and then complement activation (MAC complex included)
- MAC forms a pore
Describe presentation of acute hemolytic reactions
Acute hemolytic reactions
- Fevers / chills
- Hypotension / shock
- Dark urine / renal insufficiency
- Bleeding and prolonged PT / PTT
Acute hemolytic reaction pathogenesis involves ____
Acute hemolytic reaction pathogenesis involves intravascular RBC lysis
- Free RBC membranes with antibody activate inflammation
- Damage renal tubules -> acute tubular necrosis
- Activate clotting cascade -> DIC
Acute hemolytic reaction results from ____
Acute hemolytic reaction results from incorrect blood specimen (wrong patient / blood type)
- Mistransfusion to wrong patient
- Antibody to RBC unit undetected in screen / crossmatch
Acute hemolytic reaction tests involve ____, ____, and ____
Acute hemolytic reaction tests involve direct antiglobulin test, repeat compatability testing, and urinalysis for hemoglobinuria
Acute hemolytic reaction treatment involves ____
Acute hemolytic reaction treatment involves diuresis to protect vs acute tubular necrosis
- Plasma / platelets if needed for bleeding / coagulopathy
- Blood pressure support is needed
Transfusion-related acute lung injury presents with ___, ___, ___, and ___
Transfusion-related acute lung injury presents with dyspnea, hypoxia, often fever, and diffuse pulmonary edema ≤ 6 hours after transfusion
Transfusion-related acute lung injury results from ____
Transfusion-related acute lung injury results from donor plasma antibodies to patient WBCs
- Activated WBCs damage pulmonary capillaries
- Donors often multiparous women, pregnancy-induced antibodies
Describe treatment, testing, and preveention for transfusion-related acute lung injury
Treatment, testing, and preveention for transfusion-related acute lung injury
- Treat: respiratory support
- Test: involved donors tested for anti-HLA and anti-neutrophil antibodies
- Prevent: make plasma from male donors, test parous women platelet donors for HLA antibodies, and defer transfusion-related acute lung injury donors
Septic reaction to transfusion presents with ____, ____, ____, ____, and ____
Septic reaction to transfusion presents with fevers, chills, rigor, hypotension, and shock
Septic reaction to transfusion presents results from ___
Septic reaction to transfusion presents results from bacteria in blood bag (especially platelets)
Describe testing, treatment, and prevention of septic reactions to transfusion
Septic reactions to transfusion
- Test: Gram stain and culture residual blood bag contents
- Treat: broad-spectrum antibiotics guided by testing
- Prevent: donor health screening (antiseptic blood collection, bacterial testing / culture of all platelets)
Anaphylactic reaction to transfusion presents with ____, ____, ____, and ____
Anaphylactic reaction to transfusion presents with hypotension, shock, airway edema, and obstruction
Anaphylactic reaction to transfusion results from ____
Anaphylactic reaction to transfusion results from recipient IgE antibodies to plasma allergens
- IgA deficient patient can present with anti-IgA antibodies
Describe testing, treatment, and prevention of anaphylactic reactions to transfusion
Anaphylactic reactions to transfusion
- Test: IgA level, anti-IgA antibodies
- Treat: antihistamines, epinephrine, corticosteroids
- Prevent: wash RBCs and platelets for IgA deficient patients
Transfusion associated graft vs host disease presents with ____, ____, ____, ____, and ____
Transfusion associated graft vs host disease presents with rash, fever, diarrhea, hepatitis, and pancytopenia 3-30 days post-transfusion
- Cellular immune reaction, donor lymphocytes vs organs
Transfusion associated graft vs host disease results from ___
Transfusion associated graft vs host disease results from lack of normal rejection of transfused RBCs
- Severe immunosuppression
- Closely HLA-matched donor such as blood relative
Describe testing, treatment, and prevention of transfusion associated graft vs host disease
Transfusion associated graft vs host disease
- Test: chimerism studies of blood or tissues
- Treat: immunosuppression of graft vs host disease reaction
- Prevent: gamma irradiation to RBCs / platelets for susceptible patients
Transfusion associated graft vs host disease resuls because ___
Transfusion associated graft vs host disease resuls because donor WBCs see recipients’ other antigens as foreign
Describe RBC alloimmunization
RBC alloimmunization
- Transfusion or pregnancy exposure
- Delayed hemolytic transfusion reaction
- Destruction of transfused RBCs days after transfusion
- Restimulation of RBC antibodies after prior immunization
- RBC antibodies can disappear over time then are not detected in compatability testing
- Kidd (Jk) blood group antibodies are the most common causes
Describe HLA alloimmunization
HLA alloimmunization
- Anti-HLA antibodies, transfusion, pregnancy
- Febrile transfusion reactions
- Platelet refractoriness: HLA antigens on transfused platelets
- Organ or stem cell transplant graft rejection
- Give leukoreduced RBCs/platelets if recurrent febrile reactions, need for recurring platelet transfusions, or organ / stem cell transplant patients / candidates
Describe donor screening
Donor screening
Describe current risk infection estimates from transfusion
Current risk infection estimates from transfusion
- HIV: 1 in 1.5 million units
- Hepatitis C: 1 in 1.1 million units
- Hepatitis B virus: 1 in 1.0 million
HBV is most common but all are rare
____, ____, ____, and ____ can also be transmitted during transfusion
Zika virus, cytomegalovirus, babesios, and Creutzfeldt-Jakob disease can also be transmitted during transfusion
- Cytomegalovirus: mainly in WBCs
- Babesiosis: RBC parasite
Describe pathogen reduction technologies for transfusions
Pathogen reduction technologies for transfusions
- Solvent-detergent (pooled plasma): disrupts RBCs
- Psoralen-UV light (plasma and platelet units): UV does not penetrate RBC units
- Riboflavin-UV light (plasma and platelet units): nucleic acid damage
- Methylene blue-visible light (plasma units): nucleic acid damage
Solvent-detergent ___ disrupt non-enveloped viruses such as Hepatitis A and parvovirus
Solvent-detergent does NOT disrupt non-enveloped viruses such as Hepatitis A and parvovirus
Psoralen binds to ___, while UV light induces ___, leading to inactivation of microbes
Psoralen binds to nucleic acid, while UV light induces crosslinking, leading to inactivation of microbes
- Also prevents graft vs host disease by inactivating donor WBCs
