Principles of Blood Banking Flashcards
blood components
*whole blood
*red blood cells
*plasma (fresh frozen & 24 hr)
*platelets (single donor & whole blood derived)
*cryoprecipitate
*granulocytes
collection strategy - apheresis
*same as phlebotomy (except we can collect more)
*single donor-RBCs, platelets, plasma
*white blood cells (granulocytes, monocytes, T cells, stem cells)
*basically, separates out a single component and re-infuses the other components that we are not specifically wanting
*usually takes about 90 min
donation of 1 unit of whole blood yields:
*1 unit of packed red blood cells (PRBC)
*1 unit of random donor platelets
*1 unit of plasma (FFP or 24 hr)
*1 unit of cryoprecipitate
pre-transfusion testing of donor blood
*ABO & Rh and antibody screen
*RPR (looks for syphillis)
*HBsAg
*HBcAb
*HBV nucleic acid test
*HCV
*HIV 1 & 2
*HTLV-I/II
*west nile virus
*bacterial culture (platelets)
*chagas disease
*babesia
indication for whole blood transfusion
*transfuse (1-4 units) to treat massive hemorrhage [provides all blood components]
*massive transfusion protocol (1:1:1)
*stored in the refrigerator at 1-6 deg C
indication for packed RBC transfusion
*transfuse (1-2 units) to treat anemia
*hemoglobin usually < 7
*stored in the refrigerator at 1-6 deg C
*1 unit will increase the Hb by 1 g/dL in adults and increase Hct by 3% (pediatric: Hb increase by 2-3)
massive transfusion of PRBCs
*defined as replacement of 1 total blood volume (usually 10 units of PRBC) in less than 24 hours
*may be complicated by dilutional coagulopathy, hypocalcemia, hyperkalemia, arrhythmia
*7-10 units of plasma (1:1)
indication for platelet transfusion
*transfuse 1 unit for thrombocytopenia
*platelet count usually < 10k
*stored at room temperature (note - risk of bacterial contamination)
indication for plasma transfusion
*note - plasma contains everything in normal human plasma (all clotting factors, and ADAMTS13)
*plasma transfusions are typically used to replace multiple clotting factors at the same time:
-disseminated intravascular coagulopathy (DIC)
-to reverse warfarin
*transfuse (2 units) to treat clotting factor deficiencies
cryoprecipitate - overview
*cryo is made from FFP (fresh frozen plasma) but only provides more concentrated form of:
1. FIBRINOGEN (think of this as a fibrinogen transfusion)
2. factor VIII
3. von Willebrand factor
4. factor XIII
5. fibronectin
what are blood groups
*red blood cells express antigens on their cell surface
*some of these antigens are very relevant to patient safety when transfused:
-ABO
-Rh
-Kell, Duffy, Kidd, Ss, etc
-36 blood group systems (>300 separate RBC antigens)
RBCs - group O / “H” antigen
*H antigen is present on all human RBCs
*think of H as the “O” antigen
*H is the precursor of the A & B antigens
key point with the ABO system and antigens/antibodies
*you will NATURALLY have the ANTIBODY that is NOT your blood group:
-group A person: anti-B antibodies
-group B person: anti-A antibodies
-group AB person: NO ABO antibodies
-group O person: both anti-A & anti-B antibodies
Rh blood group - overview
*the D antigen (+ indicates that someone HAS the D antigen; - indicates that they do not have the D antigen)
*antibodies to D antigen are NOT “naturally” occurring - [ie. a D- person needs an EXPOSURE to foreign, non-self RBCs to have an antibody response (pregnancy, blood transfusion, bone marrow transplant, organ transplant)]
“type” in testing for blood transfusions
*check a patient’s (the recipient’s) ABO and Rh type
*forward type: test the PATIENT’S red cells for A or B antigen
*Rh type: test the red cells for the D antigen
*reverse type: test the PATIENT’S serum/plasma for the expected antibody (ex. if you know the pt is type A, you are checking for anti-B antibodies in the serum)
“screen” in testing for blood transfusions
*check the PATIENT’S (the recipient’s) serum/plasma for other antibodies against red cell antigens (other than ABO, such as Kell, Duffy, Kidd…)
*more relevant after a patient has already had a blood transfusion before
“cross” in testing for blood transfusions
*cross = crossmatch:
-mix the PATIENT’S serum/plasma with a sample of the DONOR red cells from the exact unit that we wish to transfuse
-if the red cells and serum mixture clumps, then the unit is INCOMPATIBLE
*endpoint of most blood bank tests is AGGLUTINATION (clumping) which indicates hemolysis
indirect antiglobulin test (antibody screen)
*detects clinically significant RBC antibodies
*screening the patient’s serum for reaction against red cells
summary - more of a pre-transfusion test; patient’s serum with donor RBCs
direct antiglobulin test/DAT (Coombs test)
*demonstrates in-vivo coating of RBCs with antibody or complement-hemolysis
*looking for auto-antibodies to their OWN RED CELLS
summary - PATIENT RED CELLS AND PATIENT ANTIBODIES; looking for antibodies against patient’s own red cells
hemolytic disease of the fetus and newborn (HDFN) - how does it happen
*mother = Rh NEG
- fetus = Rh pos
- fetal red cells enter maternal circulation
- mother synthesizes anti-D antibodies
- anti-D crosses placenta and hemolyzes fetal red cells
problematic with the SECOND pregnancy (antibodies formed in first pregnancy)
hemolytic disease of the fetus and newborn (HDFN) - erythroblastosis fetalis
*anemia with possible organ failure, edema (hydrops), jaundice, cardiac failure, liver failure
* + DAT in the fetus
*mothers with high titer of anti-D at most risk (other antibodies to red cells can cause hemolytic disease of the newborn)
*increased bilirubin & bile pigments in the amniotic fluid
*peripheral blood smear of baby
-spherocytes
-nucleated red cells
hemolytic disease of the fetus and newborn (HDFN) - how do we solve it
*Rhogam (infuse it in mothers who are Rh- at the time of delivery)
-prevents mother from making the anti-D antibodies
universal donors / recipients of RBCs vs plasma
*O blood group is universal donor of RBCS (but the universal RECIPIENT OF PLASMA)
*AB blood group is universal recipient of RBCs (but the universal DONOR OF PLASMA)
infectious ADEs of blood transfusion
*low risk of transfusion-related infections (HBV, HCV, HIV, bacteria esp in platelet transfusion, etc)
transfusion reactions
*any adverse reactions occurring at time of or after transfusion (up to 6 hours after)
*s/s:
-fever
-chills with or w/o rigors
-pain at infusion site or in the chest, abdomen, or flanks
-blood pressure changes
-respiratory distress (SOB)
-skin changes (urticaria, itching, flushing, localized edema)
-N/V
-darkened urine or jaundice
-bleeding or manifestations of consumptive coagulopathy
what to do if you suspect a transfusion reaction
*immediately discontinue the transfusion
*maintain IV access at all times, but do not infuse any additional blood products
*all tubing containing blood should be removed and replaced
*notify blood bank and transfusion medicine physician
*send transfusion reaction work-up
acute hemolytic transfusion reaction - etiology
*transfusion of ABO incompatible blood (e.g. giving A blood to an O patient with preformed anti-A)
*alloantibodies (Kell, Kidd) in recipient plasma react with corresponding antigen on donor red cells
acute hemolytic transfusion reaction - s/s
*fever, chills, back pain, and dyspnea most common
*chest pain, hypotension/shock, hemoglobinuria, cardiac arrest
*intravascular hemolysis
acute hemolytic transfusion reaction - management
*STOP TRANSFUSION! - replace tubing, maintain IV access, notify primary physician/blood bank
*supportive therapy to maintain:
-BP: IV fluids, meds to maintain BP
febrile non-hemolytic transfusion reaction - etiology
*white cell antibodies in the patient react with transfused white cells or platelets present in donor blood
*cytokine accumulation in blood product, especially platelet transfusion (TNF-alpha, IL-1, IL-6, IL-8)
febrile non-hemolytic transfusion reaction - s/s
*fever, > 1 deg C increase during or within 2 hours of completing transfusion
*chills, rigors, headache, tachycardia, myalgias
*usually no hypertension
febrile non-hemolytic transfusion reaction - prevention
*use pre-storage leukocyte reduced products (no WBC fragments)
*pre-medication with acetaminophen
urticarial (mild allergic) transfusion reaction - etiology
*recipient is sensitized to foreign donor plasma proteins
urticarial (mild allergic) transfusion reaction - s/s
urticaria (rash), flushing, itching, erythema
urticarial (mild allergic) transfusion reaction - management
if symptoms are mild, stop or slow transfusion, administer antihistamine, and then you can probably restart the transfusion
anaphylactic transfusion reaction - etiology
*IgA deficient patient:
-preformed IgG anti-IgA antibodies react with donor IgA present in the product
anaphylactic transfusion reaction - s/s
*anaphylactic shocks after a few mLs
*hypotension, flushing, rash, chills, coughing, respiratory distress, abdominal cramping, vomiting, diarrhea, loss of consciousness
anaphylactic transfusion reaction - prevention
*autologous transfusions
*IgA deficient blood products (PRBCs, platelets, plasma)
*washed RBCs and platelets
*plasma products only from IgA deficient donors
*need a transfusion medicine consult
transfusion related acute lung injury (TRALI) - etiology
*uncertain but donor related:
-HLA antibodies class I & II and neutrophil specific antibodies
-bioactive lipids accumulate in stored blood activate neutrophils
*NOT due to fluid/volume overload
note - most common cause of transfusion related fatality
transfusion related acute lung injury (TRALI) - s/s
*acute respiratory insufficiency W/O heart failure
*dyspnea, tachycardia, characteristic chest x-ray
transfusion related acute lung injury (TRALI) - prevention
*male only plasma donors
*donor screening for anti-HLA/granulocyte antibodies (female donors wiht h/o pregnancy are at risk of having these antibodies)
transfusion associated graft vs host disease (tGVHD) - etiology
*engraftment of donor lymphocytes in the bone marrow of immunosuppressed patients, setting up an immune response where the donor cells recognize the host as foreign, causing an immune “rejection” response
note - extremely rare
transfusion associated graft vs host disease (tGVHD) - s/s
*rash, diarrhea, hepatosplenomegaly
*pancytopenia
transfusion associated graft vs host disease (tGVHD) - management
*high dose steroids
transfusion associated graft vs host disease (tGVHD) - diagnosis
*skin biopsy
*test for donor T cells in recipient circulation
transfusion associated graft vs host disease (tGVHD) - prevention
*for immunosuppressed patients, IRRADIATE all blood products containing lymphocytes (esp meds that result in significant myelosuppression)
*irradiate all blood products from relatives
septic transfusion reaction - etiology
*infusion of bacterial contaminated blood products
*most common in platelets b/c stored at room temp
septic transfusion reaction - s/s
“warm shock” (fever and hypotension)
transfusion associated circulatory overload (TACO) - etiology
*administering fluid faster than the circulatory system can handle, often in setting of CHF
*especially relevant in peds, elderly, and renal failure
transfusion associated circulatory overload (TACO) - s/s
*acute transfusion reaction
*cough, dyspnea, tachycardia, rales, distended neck veins, HTN, headache
transfusion associated circulatory overload (TACO) - prevention
*request blood to be divided into smaller aliquots
*transfuse as a slower rate
*1 unit of PRBCs 3-4 hours