Unit 9 - Transfusions Flashcards
1
Q
what determines blood type
A
antigenic glycoproteins on cell membranes of erythrocytes
2
Q
what is required for a successful transfusion to occur
A
requires no antigen-Ab reaction
(plasma contains opposite antibodies from erythrocytes)
3
Q
universal donors
A
erythrocytes: O negative
plasma: AB positive
4
Q
universal acceptors
A
erythrocytes: AB positive
plasma: O negative
5
Q
RBC Antigens & Plasma antibodies - Type O
A
no RBC antigens
Anti-A and anti-B antibodies
6
Q
RBC antigens and plasma antibodies - type A
A
A RBC antigens
anti-B plasma antibodies
7
Q
RBC antigens and plasma antibodies - type B
A
B antigens
Anti-A plasma antiobdies
8
Q
RBC antigens and plasma antibodies - AB
A
A, B antigens
no plasma antibodies
9
Q
blood compatible with type A
A
A, O
10
Q
blood compatible with type O blood
A
O
11
Q
blood compatible with type B blood
A
B, O
12
Q
blood compatible with AB blood
A
A, B, AB, O
13
Q
RBC antigens and plasma antibodies for Rh-positive blood
A
D antigens
no plasma antibodies
14
Q
how can an Rh-negative person be sensitized to Rh-positive blood
A
transfusion or pregnancy (delivery)
15
Q
how can Rh-negative mother be sensitized to Rh antigen
A
Rh antigen can cross placenta during delivery and sensitize mother
16
Q
why is the first baby not at risk for Rh sensitization
A
- It takes several days for the mother to develop antibodies to the Rh antigen
- If the mother becomes sensitized and develops antibodies, a subsequent pregnancy with an Rh-positive fetus may lead to erythroblastosis fetalis (hemolytic disease of the newborn)
17
Q
when might a woman need Rhogam
A
a Rh-negative mother with 2nd pregnancy whose first baby was Rh-positive
starting at 28 weeks
18
Q
who does a fetus receive Rh antigen from
A
father
19
Q
universal PRBC donor
A
O blood
20
Q
universal FFP donor
A
type AB
21
Q
universal FFP acceptor
A
Type O
22
Q
universal RBC acceptor
A
AB
23
Q
lab test that tests for ABO and Rh-D antigens
A
type
24
Q
determines the presence of ABO and Rh-D antigens in recepient’s blood
A
typing
25
determines the presence of the most clinically significant antibodies
screening
26
provides the most accurate determination of compatibility by mixing recipient's plasma with blood in actual unit to be transfused
crossmatching
27
how long does blood typing take
5 minutes
28
how long does blood screening take
45 min
29
how long does blood crossmatching take
45 minutes
30
chance of transfusion reaction with blood typing
0.2%
31
chance of transfusion reaction with blood screening
0.6%
32
chance of transfusion reaction with blood crossmatching
0.05%
33
what does blood screening test for
most clinically significant antibodies
34
recommended order of admin. uncrossmatched blood
| (most to least favorable)
1. type-specific partially crossmatched blood
2. type-specific uncrossmatched
3. o negative uncrossmatched
35
what percent of the population is Rh-D positive
85%
36
when is it ok to use O positive blood for emergency transfusion
emergency transfusion if pt isn’t a woman of childbearing age and has not received a previous transfusion
37
1st choice for administering emergency uncrossmatched blood
type-specific partially crossmatched blood
38
hgb level that often requires transfusion
< 6 g/dL
39
hgb > ____ rarely requires transfusion
10 g/dL
40
components of PRBC transfusion
RBCs only
41
components of whole blood
RBCs
WBCs
plasma
platelet debris
fibrinogen
42
when is whole blood indicated
RBC replacement
blood volume replacement
43
components of FFP
* all coagulation factors
* fibrinogen
* plasma proteins
44
indications for FFP transfusion
* coagulopathy (PT or PTT > 1.5x control)
* warfarin reversal
* antithrombin deficiency
* massive transfusion
* DIC
* C1 esterase deficiency
45
dose of FFP for warfarin reversal
5-8 mL/kg
46
dose of FFP for coagulopathy
10-20 mL/kg
47
10-20 mL/kg of FFP increases factor concentration by:
20-30%
48
half life of factor 7
3-6 hours
49
time frame to give FFP
complete within 24 hours of thawing
50
plt count for NSGY that should get a platelet transfusion
< 100k
51
plt count that should get plt transfusion for most surgeries
< 50 k
52
components of cryopreceipitate
fibrinogen
factor 8
factor 13
vWF
53
cryo dose
5 bag pool to ↑ fibrinogen by 50 mg/dL
54
cryo infusion should be completed by:
within 6 hours of thawing
55
indications for cryo
* fibrinogen deficiency (< 80-100 mg/dL)
* von Willebrand disease
* hemophilia
56
what should blood loss be replaced with
crystalloid or colloid solutions until the risk of anemia outweighs the risk of transfusion
57
when should pts with CAD be transfused
when hematocrit falls below 28 - 30%
58
indicators of tissue perfusion that should be considered before transfusing
DO2, SvO2, acid-base status, lactate, hemodynamic instability, myocardial ischemia, and oliguria
59
if a 70 kg patient has a Hgb of 12 g/dL and acutely loses 1L of blood, what's the new Hgb value?
12 g/dL
Even though the patient has lost 1/5th of his blood volume, the amount of hgb per deciliter of blood hasn’t changed.
60
what does the MABL calculation assume about the patient?
euvolemic
61
blood volume of premature neonate
90-100 mL/kg
62
blood volume of full term neonate
80-90 mL/kg
63
blood volume of infants
75-80 mL/kg
64
blood volume of school aged child
70 mL/kg
65
blood volume of adults
70 mL/kg
66
MABL calculation
67
volume and hct of 1 unit PRBCs
~300 mL
Hct ~ 70%
68
how does 1 unit PRBCs affect hgb & hct
increases Hgb by 1 g/dL and Hct by 2 - 3%
69
how do erythrocytes convert glucose to ATP
Erythrocytes do not contain mitochondria, so they rely on glycolysis and the lactic acid pathway to convert glucose to ATP
70
temp blood is stored
1-6 degrees C
| extends its lifespan by slowing the rate of glycolysis
71
temp blood is stored
1-6 degrees C
| extends its lifespan by slowing the rate of glycolysis
72
what is citrate
anticoagulant that inhibits calcium (factor 4)
After transfusion of multiple units, the citrate load can cause hypocalcemia
73
function of phosphate in stored blood
buffer that combats acidosis
74
primary substrate for glycolysis
dextrose
75
additives that increase shelf life of stored blood
citrate
phosphate
dextrose
adenine
76
what is adenine
substrate that helps RBCs re-synthesize ATP
extends storage time from 21 to 35 days
77
newer preservatives extend storage time of blood to:
42 days
78
what is red blood cell storage lesion
important physiochemical changes that occur during blood storage
79
oxyhgb curve with banked blood
decreased 2,3-DPG shifts curve to the left
80
why is pH of banked blood decreased
increased lactic acid as a consequence of preservation
81
why should PRBC transfusions be used cautiously in neonates and renal failure
contains increased K+
82
what is leukoreduction
Removes WBCs from banked RBCs and platelets
83
risks reduced by leukoreduction
* Febrile nonhemolytic transfusion reactions
* CMV transmission
* HLA alloimmunization
84
what is alloimmunization
process where the body develops antibodies against non-self antigens
85
what is HLA alloimmunization
when the body develops antibodies against human leukocyte antigens
86
what is HLA alloimmunization
when the body develops antibodies against human leukocyte antigens
87
how does HLA alloimmunization affect platelets
it can make the patient "refractory" to platelet transfusions - the body attacks the HLA proteins that are present on the platelet's surface
88
most common cause of platelet refractoriness
HLA alloimmunization
89
what is washing blood products
Washing blood products with saline removes any remaining plasma (and antigens) in the donor RBCs (RBC antigens are not removed)
90
process that prevents anaphylaxis in IgA deficient patients
washing blood products
91
what is irradiation of blood products
exposes units to gamma radiation
disrupts WBC DNA in the donor cells & destroys donor leukocytes
92
process for banked blood that prevents graft v host disease in immunocompromised patients
irradiation
93
what is graft v host disease
donor leukocytes attack recipient bone marrow
s/s: pancytopenia, fever, hepatitis, and diarrhea
94
populations that benefit from irradiated cells
* leukemia
* lymphoma
* hematopoietic stem cell transplants
* DiGeorge syndrome
95
most common infectious complication of blood producr transfusion
CMV
| risk greatly reduced with leukoreduction
96
most common infectious complication of blood product transfusion
CMV
| risk greatly reduced with leukoreduction
97
infectious risks of blood transfusion from most to least common
CMV > hepatitis B > hepatitis C > HIV
98
in up to 85% of infections, hepatitis C can lead to:
* cirrhosis
* hepatocellular carcinoma
* liver failure
* death
99
bacterial contamination and sepsis is most common with what blood product
platelets
| stored at room temp
100
what causes an acute hemolytic transfusion reaction
Complement activated in recipient’s blood
plasma antibodies attack antigens present on donor blood cell membranes
101
most lethal acute hemolytic transfusion reaction
ABO incompatibility
102
Most catastrophic complications of intravascular hemolysis with hemolytic transfusion rxn
renal failure, DIC, hypotension
103
s/s acute hemolytic transfusion reaction
* Presenting sign under anesthesia usually **hemoglobinuria**
* Also: hypotension, bleeding, fever, chills, chest pain, dyspnea, nausea, flushing
104
which blood product contains the highest conentration of fibrinogen
cryo
105
a 5 bag pool of cryo is expected to increase fibrinogen by:
50 mg/dL
106
blood product indicated to restore O2 carrying capacity
PRBCs
107
blood product that should not be given with a filter or warmer
platelets
108
what should determine decision to transfuse when Hgb 6-10 g/dL
based on patient's physiologic response to anemia
109
blood additive that is a substrate for ATP synthesis
adenine
110
blood additive that is a substrate for glycolysis
dextrose
111
citrate binds what coagulation factor
4 (calcium)
112
additive in blood that acts as a buffer to combat acidosis
phosphate
113
blood component processing that removes plasma antigens
washing
114
blood component processing that exposes blood to gamma radiation
irradiation
115
risk of bacterial contamination from PRBCs
1 in 35,000
116
risk of bacterial contamination from platelets
1 in 15,000
117
antibodies contained in O blood
anti-A
anti-B
118
what causes a hemolytic transfusion reaction
a patient receives an incompatible blood product
| ABO incompatibiltiy is the most lethal
119
what causes a hemolytic transfusion reaction
a patient receives an incompatible blood product
| ABO incompatibiltiy is the most lethal
120
complications of hemolytic transfusion reaction
flushing
renal failure (acute tubular necrosis)
DIC
hemodynamic instability
121
treatment of hemolytic transfusion reaction
* stop transfusion
* maintain UOP > 75-100 mL/hr
* alkalinize urine (bicarb)
* check plts, PT, fibrinogen
* send unused blood to blood bank for crossmatch
122
what leads to DIC in hemolytic reaction
erythrocyin is released from RBC and activates intrinsic clotting cascade
leads to uncontrolled fibrin formation & consumes body’s supply of plts & factors 1, 2, 5, and 7
123
most common adverse reaction assoc. with transfusion
febrile transfusion reaction (non-hemolytic)
124
methods to maintain UOP with acute hemolytic transfusion reaction
* IVF
* 12.5-15 g mannitol
* 20-40 mg lasix
125
3 key signs of acute hemolytic transfusion reaction under GA
1. hemoglobinuria
2. hypotension
3. bleeding
126
6 signs of acute hemolytic transfusion reaction that are masked by GA
1. fever
2. chills
3. chest pain
4. dyspnea
5. nausea
6. flushing
127
cause of febrile reactions
Pyrogenic cytokines and intracellular components are released from leukocytes in the donor blood product
128
treatment of febrile transfusion reaction
supportive
acetaminophen
129
presentation of febrile transfusion reaction
Fever, chills, headache, nausea, and malaise (hypotension, chest pain, and dyspnea are less common)
130
cause of allergic transfusion reaction
Foreign proteins in the donor blood product
131
presentation of allergic transfusion reaction
Urticaria with itching (most common) and facial swelling
132
treatment of allergic transfusion reaction
Supportive + antihistamines.
Minor reaction = Continue transfusion
133
s/s major allergic transfusion reaction
dyspnea, laryngeal edema, or hemodynamic instability)
134
management of major allergic transfusion reaction
stop the transfusion and treat it as anaphylaxis
135
what is TRALI
Transfusion Related Acute Lung Injury
Form of non-cardiogenic pulmonary edema that occurs following transfusion
136
most common cause of transfusion-related mortality in US
TRALI
137
cause of TRALI
HLA & neutrophil antibodies in donor plasma
138
patho of TRALI
* donor antibodies activate neutrophils in lungs
* causes endothelial injury
* results in capillary leak and pulmonary edema
* leads to impaired gas exchange, hypoxemia, and acidosis
139
**recipient** patient populations at higher risk of TRALI
* critically ill (highest risk)
* anyone susceptible to acute lung injuries (sepsis, burns, post-CPB)
140
blood products with highest risk of TRALI
FFP
platelets
141
**donor** groups at higher risk for TRALI
* multiparous women (highest)
* hx blood transfusion
* hx organ transplant
142
diagnostic criteria of TRALI
* Onset < 6 hours following transfusion
* Bilateral infiltrates on frontal CXR
* PaO2/FiO2 < 300 mmHg or SpO2 < 90% on room air
* Normal PAOP (no LA HTN or volume overload)
143
management of TRALI
* Maximize PEEP
* Low tidal volume
* Avoid overhydration
144
what is TACO
Transfusion Related Circulatory Overload
State of volume overload caused by expanding the plasma volume beyond patient’s compensatory ability
145
s/s TACO
* pulmonary edema
* hypervolemia
* LV dysfunction
* mitral regurg 2/2 volume overload
* ↑ PAOP
* ↑ BNP
146
consequences of massive transfusion
* alkalosis
* hypothermia
* hyperglycemia
* hypocalcemia
* hyperkalemia
147
why is massive transfusion assoc with alkalosis
citrate metabolism to bicarb in liver
148
why is massive transfusion assoc with hypothermia
transfusion of cold blood
149
why is massive transfusion assoc with hyperglycemia
dextrose additive to stored blood
150
why is massive transfusion assoc with hypocalcemia
binding of calcium by citrate
151
why is massive transfusion assoc with hyperkalemia
admin of older blood
152
s/s heart failure from TACO
* orthopnea
* cyanosis
* tachycardia
* HTN
* pulm edema
153
hallmark of heart failure with TACO
resp distress d/t pulmomary edema
154
hallmark of heart failure with TACO
resp distress d/t pulmomary edema
155
why can admin of PRBCs to neonates cause hyperkalemia and cardiac arrest
When RBCs are stored, the cell membrane becomes dysfunctional & allows K+ to leak
156
lethal triad of trauma
1) Acidosis
2) Hypothermia
3) Coagulopathy
157
how to reduce risk of hyperkalemia with RBC admin
admin. washed or fresh cells that are < 7 days old
158
why is acidosis assoc with trauma
* Hypoperfusion & hypoxemia reduce O2 delivery
* Body converts from aerobic to anaerobic metabolism = lactic acidosis
159
why is trauma assoc with hypothermia
Hemorrhage and hypoperfusion impair the body’s ability to regulate heat
160
why is trauma assoc with coagulopathy
* Coagulation is an enzymatic process - impaired by hypothermia
* acidosis also impairs enzymatic structures
* massive volume causes dilutional coagulopathy
161
at what temp are PT and PTT prolonged
< 34 deg C
162
when is intraoperative blood salvage used
typically used during cardiac, major vascular, trauma, liver transplant, and orthopedic surgery when blood loss is expected to exceed 1,000 mL or 20% of the patient's expected blood volume
## Footnote
also indicated for patients with pre-existing anemia or those that refuse allogeneic blood products, such as Jehovah's Witnesses.
163
how is intraoperative blood salvage performed
1. blood loss collected by dedicated device
2. filtered & centrifuged
3. concentrated & washed
4. diluted with NS to final Hct 60-70%
5. ready to be transfused
164
which has better O2-carrying capacity - banked or salvaged blood?
salvaged
contain higher concentrations of 2,3-DPG and ATP, and they are better able to maintain their biconcave shape
165
consequence of transfusing a large volume of salvaged blood
dilutional coagulopathy
| Platelets and coagulation factors are not returned to the patient
166
consequence of transfusing a large volume of salvaged blood
dilutional coagulopathy
| Platelets and coagulation factors are not returned to the patient
167
risks of using salvaged blood
Contamination of collected blood by urine, feces, amniotic fluid, or malignant cells
* Fever
* Non-immunogenic hemolysis
| (rare)
168
risks of using salvaged blood
Contamination of collected blood by urine, feces, amniotic fluid, or malignant cells
* Fever
* Non-immunogenic hemolysis
| (rare)
169
contraindications for salvaged blood
* Sickle cell disease
* Thalassemia
* Topical drugs in sterile field such as betadine, chlorhexidine, and topical antibiotics
* Infected surgical site
* Oncologic procedures
* neoplastic disease
170
why is salvaged blood use controversial in c sections
theoretical risk of anaphylactoid syndrome of pregnancy/AFE
171
s/s citrate toxicity from blood transfusions
* hypocalcemia
* hypotension
* longer QT
172
estimating hgb based on hct
hgb can be estimated to be 1/3 of hct
