Blood Bank Exam 4 Flashcards
1
Q
What blood types can an A- person receive?
A
A neg and O neg
2
Q
What blood types can an A+ person receive?
A
A pos, A neg, O pos, O neg
3
Q
What are the 6 steps to ensure patient safety for pre-transfusions?
A
- Positive patient identification
- Review of blood bank history
- ABO, Rh, Antibody screen must agree with history
- Selection of ABORh compatible donor red cells
- Perform crossmatch
- Compatible units must be labeled properly
4
Q
Every blood bank sample is good for ____ hours.
A
72 (3 days)
5
Q
What is a crossmatch?
A
Patient plasma mixed with donor red cells to detect ABO incompatibilities
6
Q
What is an immediate spin crossmatch vs extended spin crossmatch?
A
Immediate spin will detect ABO incompatibilities while extended spins will detect antibody incompatibilities.
7
Q
When can you perform an electronic cross match?
A
When a patient has no current/history of clinically significant antibodies and they have 2 ABO/Rh tests on file.
8
Q
What must be included on a properly labeled compatible unit?
A
Name, MRN, Unit number, Unit ABORh, Patient ABORh, Expiration date, Product type, and Compatibility status
9
Q
What are 2 things a compatible crossmatch will NOT guarentee?
A
- Normal survival of transfused cells
- Will not prevent immunization of recipient
10
Q
What are 4 causes for an incompatible crossmatch?
A
- Incorrect ABO of donor or patient
- Allo-antibody in the patient that reacts against an antigen on the donor cells
- Auto anitbody that reacts against antigen donor cells
- Positive DAT in donor
11
Q
During an emergency release, what blood types will you give?
A
Group specific if available, if not give group O.
12
Q
During emergency release of blood product, what would you give to young women and children?
A
O-
13
Q
During emergency release of blood product, what would you give to males and females over childbearing ages?
A
O+
14
Q
T/F: Blood is crossmatched before an emergency release.
A
FALSE; blood is crossmatched after blood has already been given.
15
Q
Emergency release blood is at the discretion of the blood banker (T/F).
A
False; it is at the discretion of the physician and you need written consent.
16
Q
Why should you always retain a segment of blood from issued donor unit during an emergency release?
A
There is a retrospective T/S + crossmatch performed after the blood has already been issued. If incompatibility is found, notify doctor and BB physician.
17
Q
What is an MTP?
A
Massive Transfusion Protocol: a total volume exchange of blood within a 24 hour period.
18
Q
Average male has ___-___ units of blood in circulation.
A
10-12
19
Q
How long must you maintain recipient specimen and donor samples for post MTP?
A
7 days
20
Q
What do you give during a massive transfusion protocol?
A
pRBCs, FFP, Cryo, and platelets
21
Q
What is an autologous unit?
A
Patients donate their own RBC for a procedure and it is transfused back into that patient when required.
22
Q
T/F: Autologous units can be used for patients other than the one who donated them.
A
FALSE; if the blood is not used for the patient who donated them, they must be discarded.
23
Q
Why do you only do forward typing on neonatal transfusions <4 months of age?
A
they are unable to produce their own antibodies. Look at maternal reverse type for antibodies.
24
Q
During transfusion of neonates, if the maternal antibody screen is negative, what do you give them?
A
ABO/Rh compatible syringes from initial unit with no repeat screens on current admission
25
During transfusion of neonates, if the maternal antibody screen is positive, what do you give them?
Antigen negative units and ABO/Rh compatible
26
Neonatal RBC transfusions are given in a _________.
Syringe (aliquot from mother/main unit)
27
What are the special standards for neonatal transfusion?
- Forward typing only
- Must be less than 7 days old
- O neg blood or compatible with mother and infant
- CMV-negative and leukocyte-reduced/irradiated
- Hemoglobin S negative for hypoxic newborns
28
What is the dose for the transfusion of a neonate?
10 mL/kg over 2 to 3 hours
29
What are the requirements for the reissue of blood back to the blood bank?
Must be within 10 degrees C and within 30 minutes of issue; must have at least one segment of the donor tubing attached to the container; container closure has not been disturbed
30
What is MSBOS?
Maximum Surgical Blood Order Schedule; establishes realistic blood ordering levels for certain procedures based off OR needs
31
When is MSBOS problematic?
When inventory is low with active traumas that also need blood
32
If a sample is received at 8/22/22 at 6:09 pm, when does the sample expire?
8/25/22 at 11:59 pm.
33
What is the expiration date of a normal T/S specimen in the blood bank?
3 days
34
Someone with blood type B neg needs a transfusion. List the order of blood in preference of issue.
B neg, O neg
35
Someone with A+ blood needs a transfusion. List the order of blood in preference of issue.
A+, A neg, O pos, O neg
36
Someone with AB+ blood needs a transfusion. List the order of blood in preference of issue.
AB+, AB neg, A pos, A neg, B pos, B neg, O pos, O neg
37
What are unexpected antibodies?
Antibodies other than those that naturally occur or that are expected to detect (like anti B for an A blood type)
38
What are autoantibodies?
Antibodies that react with antigens present on the antibody producer's red cells - violates Landsteiner's rule
39
Cold auto-antibodies
React at or below RT (IgM)
40
Warm auto-antibodies
React best at 37C (IgG)
41
What is the DAT/AC results expected to be if a person has an autoantibody?
Positive
42
What is the purpose of an antibody screen?
To detect (yes or no) if antibodies are present.
43
When would you perform an antibody screen and what tube type would they come in?
EDTA lavender top or SST red top; perform prior to transfusion
44
What are the reagent cells in antibody screns?
Group O cells
45
Is an antibody screen an IAT or DAT?
IAT
46
What is an antibody screen?
Patient plasma/serum mixed with reagent RBCs using in-vitro sensitization to look for the presence of antibodies
47
What are the 3 phases of testing for an antibody screen?
Immediate spin/room temp --> IgM
37 C --> IgG
AHG and CC (If AHG reaction is negative)
48
What are enhancement medias LISS and PEG used for?
During 37C and AHG testing for antibodies to increase antibody binding
49
What to do next after positive antibody screen?
Antibody panel --> Antigen typing --> Crossmatching
50
T/F: Positive antibody screen is a critical result.
TRUE: nurse/doctor should be notified of a delay if blood products are needed
51
What is an ABID and what does it tell us?
An antibody identification panel that uses 10-20 type O panel cells telling us which antibody is present
52
What is an autocontrol?
Patient cells mixed with patient serum to determine auto-antibodies (AC = positive if autoantibodies present)
53
What are the 4 different enzymes available to treat cells?
Ficin, Papain, Trypsin, Bromelin
54
What enzymes will denature Kell?
DTT to make ZZAP
55
What antibodies are enhanced by enzymes?
Rh, Kidd, Lewis, I, P
56
What antibodies are destroyed by enzymes?
M, N, S, Duffy
57
What antibodies are unaffected by Ficin, Bromelin, Trypsin, and Papain?
Kell
58
LISS vs PEG
LISS increases rate of antibody uptake
PEG concentrates the antibody in the test environment in LISS
59
What are adsorptions for?
Remove unwanted antibody from serum or plasma like cold or warm autoantibody
60
Alloadsorption
Tested with cells of known phenotype, other than the patients cells
61
Auto-adsorptions
Tests with the patients cells, Ab/Ag complexes removed and repeat
62
Adsorptions can be combined with ________ for increased antibody recovery and testing.
Elution studies
63
What do elutions do?
Remove antibodies bound to RBCs for ID and testing and can be removed by acid or freezing
64
When are elutions used?
On Positive DAT or AC with recent transfusion history
65
What serves as the QC during elutions?
Buffer washes are used to prepare the RBCs and the last buffer wash must be saved for QC. Last wash must be negative for eluate to be valid.
66
Elutions are helpful for suspected _____ and _______.
HDFN and AIHA
67
Adsorptions vs elutions
Adsorptions remove antibody from serum/plasma.
Elutions remove antibody from RBCs.
68
Acid elution
Uses digitonin, RBCs are destroyed, IgG can be collected from supernatant
69
Lui-Freeze elution
Freeze cells to hemolyze them; RBCs lyse during freeze thaw (not as common, not as good)
70
How to perform a rule out:
Only perform rule outs on negative reactions and then perform homozygous antigen rule outs.
71
Exceptions to Kell antigen during rule outs
Finding a homozygous K is difficult, so must have 2-3 heterozygous negatives to rule out K
72
T/F: In ABID rule outs, if more than one phase of reactivity was performed like in tube, then all phases must be evaluated if there is any differences in reactivity between the 3 phases
True
73
What is the rule of 3?
Used after you have determined the antibody's specificity; must have 3 negative and 3 positive reactions for the antibody you think is causing the reactivity.
74
Having to use another panel to find another cell to satisfy the rule of three are known as _______
select cells
75
When would you use select cells?
When you need more donor cells to identify the antibody or more cells are needed to satisfy the rule of three
76
What do you do next if the antibody ID is known or partially known?
Use a new panel and use donor cells that are negative for the antibody's reactivity but are also homozygous positive for the antigens you want to rule out OR
use select cells that are positive or negative for the antibodies' specificity to complete the rule of 3
77
What do you do next if the antibody ID unknown after the first panel?
Run a new panel of cells for additional rule outs
78
Positive AC vs Negative AC
Positive AC = autoantibody
Negative AC = alloantibody
79
If the AC is positive, what is ordered? What if that is also positive?
DAT is ordered after positive AC. If DAT is positive and the patient was recently transfused, elution may be indicated.
80
DAT: in vivo or In vitro?
AC: in vivo or in vitro?
DAT in vivo
AC in vitro
81
After confirming the antibody from an ABID, what do you do next?
Perform antigen typing if the patient has not been transfused within the past 3 months
82
What is the formula to determine # of antigen units to type?
units = the number of request units/the negative antigen frequency per antibody
83
The most feared hazard of blood transfusions is ________.
hemolysis
84
Intravascular hemolysis
Antibody initiates attachment of complement to the cell membrane and cells lyse in the blood stream (bad hemolysis)
85
Which antibodies are great complement activators?
IgM
86
____ antibodies are capable of intravascular hemolysis.
ABO
87
Extravascular hemolysis
Antibody remains attached as immunoglobulins on the surface of circulating cells; Complement sequence goes no further than the attachment of C3b (better controlled hemolysis)
88
List the acute transfusion reactions
Acute hemolytic transfusion reaction
Febrile, non-hemolytic reaction
Allergic reaction
Bacterial contamination
Anaphylactic reaction
Transfusion associated circulatory overload
Transfusion related acute lung injury
89
Acute hemolytic transfusion reaction
Intravascular hemolysis due to activation of Complement; usually due to ABO incompatibility through negligence or clerical error
90
DAT results in acute hemolytic transfusion reaction
Positive DAT
91
Diagnosis of acute hemolytic transfusion reaction
Positive DAT, decreased Hgb, Increased bilirubin, decreased haptoglobin
92
What is the most common type of transfusion reaction?
Febrile, non-hemolytic reactions
93
What is febrile, non-hemolytic reaction?
Acute reaction caused by HLA antibodies present in recipient's plasma against antigens on transfused WBCs and/or platelets
94
T/F: Febrile, non-hemolytic reactions are more common in men.
False- more common in women because of exposure to more antigens during pregnancy
95
DAT in febrile, non-hemolytic reactions
DAT negative
96
How to prevent and treat febrile, non-hemolytic reactions?
Leukoreduced blood products to prevent; antipyretics to treat
97
Allergic reaction transfusion reaction
Acute; due to allergen present in donor plasma that elicits an immune response
98
DAT/hemolysis in allergic reaction transfusion reaction?
Negative DAT; no hemolysis
99
Symptoms of allergic reaction transfusion RXN?
erythema and pruritus
100
Bacterial contamination or Transfusion Associated Sepsis (3 infection routes)
1. during donor phlebotomy
2. during component preparation
3. pre-existing infection in the donor
101
When is bacterial contamination in transfusions more common?
Room temperature products (aka platelets)
102
What bacteria can survive blood products and can be associated with bacterial contamination during a transfusion?
Yersinia, Pseudomonas, Serratia
103
Diagnosis of bacterial contamination during transfusion
Negative DAT, gram stain blood bag, culture blood bag, culture patient
104
How to prevent bacterial contamination in transfusions?
Inspect blood before you use it, if there are clots, it is cloudy, or it is purple in color it is bad.
105
Anaphylactic transfusion reactions
Acute; seen in IgA deficient patients who develop anti-IgA through pregnancy or transfusion - requires units to be washed
106
Diagnosis of anaphylactic reactions
Negative DAT, IgA deficiency workup
107
Transfusion Associated Circulatory Overload (TACO)
Hypervolemia (fluid overload in lungs) due to excessive volume or speed or infusion
108
What population does TACO mostly occur?
Elderly or compromised cardiac/pulmonary function
109
Symptoms of TACO
Severe hypoxemia, increased BP, jugular vein distension,
110
Diagnosis of TACO
Chest X-ray will show pulmonary edema, cardiomegaly and distended pulmonary artery, atrial hypertension
111
Transfusion Related Acute Lung Injury (TRALI)
Immune-based damage to lungs due to HLA specific donor antibodies directs against the patient's granulocytes - activates complement
112
Symptoms of TRALI
Fever, hypoxemia, chills/cough, low BP, cyanosis, pulmonary edema
113
Diagnosis of TRALI
Chest x ray will show bilateral lung infiltrates
Donor test for HLA antibodies
Recipient tested for HLA antigens
114
Delayed vs Acute transfusion rxns
Acute is during or right after a transfusion
Delayed is weeks or months after transfusion
115
Is delayed or acute hemolytic transfusion reaction more common?
Delayed
116
Delayed hemolytic transfusion reaction
Seen about 5-7 days post transfusion; antibody is produced against an antigen on the transfused cells
117
Delayed hemolytic transfusion reaction DAT
Positive
118
Transfusion transmitted diseases
Delayed reactions caused by diseases such as hepatitis, CMV, malaria, syphilis, HIV etc
119
Why are transfusion transmitted diseases delayed and not acute like bacterial contamination?
Have to replicate in host genome which takes time
120
What can prevent transmission of CMV in transfusions?
Leukoreduced or IRR blood products
121
All blood products in US and Europe are ___.
LR
122
What causes Syphilis?
Treponema pallidum
123
Why can you not donate blood for a year if you have had a recent tattoo or piercing?
HIV window period is critical and can take time to develop antibodies so can be a false negative via testing for blood donor centers
124
What is the cause of GVHD?
donor lymphocytes engraft or react against recipient foreign tissues (in normal situation, people can reject lymphocytes. in immunosuppressed, cannot reject lymphs and they proliferate and grow in recipients body)
125
What community is the biggest problem with GVHD?
immunosuppressed patients, BM transplants, chemo patients, infants and fetuses
126
Diagnosis of GVHD
Pancytopenia, identify donor engraftment
127
Prevention of GVHD
Gamma irradiation of cellular blood components as necessary
128
Post Transfusion Purpura
Caused by anti-HPA-1a antigen - destroys all PLTs
129
What population of people are most commonly associated with post transfusion purpura?
Women with multiple pregnancies because they have been antigenated so many times
130
Symptoms of post transfusion purpura
bleeding, generalized purpura, severe thrombocytopenia
131
Diagnosis of PTP
thrombocytopenia, HPA antibodies
132
Iron Overload
Causes multiple organ failure - patients receiving chronic transfusions are at risk
133
Diagnosis of iron overload
Increased ferritin levels
134
Responsibilities of the blood bank post transfusion
1. perform clerical check
2. compare pre and post transfusion specimens for signs of icterus or hemolysis
3. perform ABORh check on post transfusion specimen
4. Perform DAT on post transfusion specimen
5. Perform T/S on new sample and invalidate old sample
135
What are other tests that can be ordered to confirm a transfusion reaction?
Urine sample to test for free hgb, bilirubin test, serum haptoglobin
136
Why is it important to irradiate blood products?
To eliminate WBC to prevent graft vs host disease
137
How much irradiation must be delivered to irradiate blood?
25 gray units to the center, 15 gray units to the periphery
