Unit 9 - Transfusions Flashcards
what determines blood type
antigenic glycoproteins on cell membranes of erythrocytes
what is required for a successful transfusion to occur
requires no antigen-Ab reaction
(plasma contains opposite antibodies from erythrocytes)
universal donors
erythrocytes: O negative
plasma: AB positive
universal acceptors
erythrocytes: AB positive
plasma: O negative
RBC Antigens & Plasma antibodies - Type O
no RBC antigens
Anti-A and anti-B antibodies
RBC antigens and plasma antibodies - type A
A RBC antigens
anti-B plasma antibodies
RBC antigens and plasma antibodies - type B
B antigens
Anti-A plasma antiobdies
RBC antigens and plasma antibodies - AB
A, B antigens
no plasma antibodies
blood compatible with type A
A, O
blood compatible with type O blood
O
blood compatible with type B blood
B, O
blood compatible with AB blood
A, B, AB, O
RBC antigens and plasma antibodies for Rh-positive blood
D antigens
no plasma antibodies
how can an Rh-negative person be sensitized to Rh-positive blood
transfusion or pregnancy (delivery)
how can Rh-negative mother be sensitized to Rh antigen
Rh antigen can cross placenta during delivery and sensitize mother
why is the first baby not at risk for Rh sensitization
- 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)
when might a woman need Rhogam
a Rh-negative mother with 2nd pregnancy whose first baby was Rh-positive
starting at 28 weeks
who does a fetus receive Rh antigen from
father
universal PRBC donor
O blood
universal FFP donor
type AB
universal FFP acceptor
Type O
universal RBC acceptor
AB
lab test that tests for ABO and Rh-D antigens
type
determines the presence of ABO and Rh-D antigens in recepient’s blood
typing
determines the presence of the most clinically significant antibodies
screening
provides the most accurate determination of compatibility by mixing recipient’s plasma with blood in actual unit to be transfused
crossmatching
how long does blood typing take
5 minutes
how long does blood screening take
45 min
how long does blood crossmatching take
45 minutes
chance of transfusion reaction with blood typing
0.2%
chance of transfusion reaction with blood screening
0.6%
chance of transfusion reaction with blood crossmatching
0.05%
what does blood screening test for
most clinically significant antibodies
recommended order of admin. uncrossmatched blood
(most to least favorable)
- type-specific partially crossmatched blood
- type-specific uncrossmatched
- o negative uncrossmatched
what percent of the population is Rh-D positive
85%
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
1st choice for administering emergency uncrossmatched blood
type-specific partially crossmatched blood
hgb level that often requires transfusion
< 6 g/dL
hgb > ____ rarely requires transfusion
10 g/dL
components of PRBC transfusion
RBCs only
components of whole blood
RBCs
WBCs
plasma
platelet debris
fibrinogen
when is whole blood indicated
RBC replacement
blood volume replacement
components of FFP
- all coagulation factors
- fibrinogen
- plasma proteins
indications for FFP transfusion
- coagulopathy (PT or PTT > 1.5x control)
- warfarin reversal
- antithrombin deficiency
- massive transfusion
- DIC
- C1 esterase deficiency
dose of FFP for warfarin reversal
5-8 mL/kg
dose of FFP for coagulopathy
10-20 mL/kg
10-20 mL/kg of FFP increases factor concentration by:
20-30%
half life of factor 7
3-6 hours
time frame to give FFP
complete within 24 hours of thawing
plt count for NSGY that should get a platelet transfusion
< 100k
plt count that should get plt transfusion for most surgeries
< 50 k
components of cryopreceipitate
fibrinogen
factor 8
factor 13
vWF
cryo dose
5 bag pool to ↑ fibrinogen by 50 mg/dL
cryo infusion should be completed by:
within 6 hours of thawing
indications for cryo
- fibrinogen deficiency (< 80-100 mg/dL)
- von Willebrand disease
- hemophilia
what should blood loss be replaced with
crystalloid or colloid solutions until the risk of anemia outweighs the risk of transfusion
when should pts with CAD be transfused
when hematocrit falls below 28 - 30%
indicators of tissue perfusion that should be considered before transfusing
DO2, SvO2, acid-base status, lactate, hemodynamic instability, myocardial ischemia, and oliguria
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.
what does the MABL calculation assume about the patient?
euvolemic
blood volume of premature neonate
90-100 mL/kg
blood volume of full term neonate
80-90 mL/kg
blood volume of infants
75-80 mL/kg
blood volume of school aged child
70 mL/kg
blood volume of adults
70 mL/kg
MABL calculation
volume and hct of 1 unit PRBCs
~300 mL
Hct ~ 70%
how does 1 unit PRBCs affect hgb & hct
increases Hgb by 1 g/dL and Hct by 2 - 3%
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
temp blood is stored
1-6 degrees C
extends its lifespan by slowing the rate of glycolysis
temp blood is stored
1-6 degrees C
extends its lifespan by slowing the rate of glycolysis
what is citrate
anticoagulant that inhibits calcium (factor 4)
After transfusion of multiple units, the citrate load can cause hypocalcemia
function of phosphate in stored blood
buffer that combats acidosis
primary substrate for glycolysis
dextrose
additives that increase shelf life of stored blood
citrate
phosphate
dextrose
adenine
what is adenine
substrate that helps RBCs re-synthesize ATP
extends storage time from 21 to 35 days
newer preservatives extend storage time of blood to:
42 days
what is red blood cell storage lesion
important physiochemical changes that occur during blood storage
oxyhgb curve with banked blood
decreased 2,3-DPG shifts curve to the left
why is pH of banked blood decreased
increased lactic acid as a consequence of preservation
why should PRBC transfusions be used cautiously in neonates and renal failure
contains increased K+
what is leukoreduction
Removes WBCs from banked RBCs and platelets
risks reduced by leukoreduction
- Febrile nonhemolytic transfusion reactions
- CMV transmission
- HLA alloimmunization
what is alloimmunization
process where the body develops antibodies against non-self antigens
what is HLA alloimmunization
when the body develops antibodies against human leukocyte antigens
what is HLA alloimmunization
when the body develops antibodies against human leukocyte antigens
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
most common cause of platelet refractoriness
HLA alloimmunization
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)
process that prevents anaphylaxis in IgA deficient patients
washing blood products
what is irradiation of blood products
exposes units to gamma radiation
disrupts WBC DNA in the donor cells & destroys donor leukocytes
process for banked blood that prevents graft v host disease in immunocompromised patients
irradiation
what is graft v host disease
donor leukocytes attack recipient bone marrow
s/s: pancytopenia, fever, hepatitis, and diarrhea
populations that benefit from irradiated cells
- leukemia
- lymphoma
- hematopoietic stem cell transplants
- DiGeorge syndrome
most common infectious complication of blood producr transfusion
CMV
risk greatly reduced with leukoreduction
most common infectious complication of blood product transfusion
CMV
risk greatly reduced with leukoreduction
infectious risks of blood transfusion from most to least common
CMV > hepatitis B > hepatitis C > HIV
in up to 85% of infections, hepatitis C can lead to:
- cirrhosis
- hepatocellular carcinoma
- liver failure
- death
bacterial contamination and sepsis is most common with what blood product
platelets
stored at room temp
what causes an acute hemolytic transfusion reaction
Complement activated in recipient’s blood
plasma antibodies attack antigens present on donor blood cell membranes
most lethal acute hemolytic transfusion reaction
ABO incompatibility
Most catastrophic complications of intravascular hemolysis with hemolytic transfusion rxn
renal failure, DIC, hypotension
s/s acute hemolytic transfusion reaction
- Presenting sign under anesthesia usually hemoglobinuria
- Also: hypotension, bleeding, fever, chills, chest pain, dyspnea, nausea, flushing
which blood product contains the highest conentration of fibrinogen
cryo
a 5 bag pool of cryo is expected to increase fibrinogen by:
50 mg/dL
blood product indicated to restore O2 carrying capacity
PRBCs
blood product that should not be given with a filter or warmer
platelets
what should determine decision to transfuse when Hgb 6-10 g/dL
based on patient’s physiologic response to anemia
blood additive that is a substrate for ATP synthesis
adenine
blood additive that is a substrate for glycolysis
dextrose
citrate binds what coagulation factor
4 (calcium)
additive in blood that acts as a buffer to combat acidosis
phosphate
blood component processing that removes plasma antigens
washing
blood component processing that exposes blood to gamma radiation
irradiation
risk of bacterial contamination from PRBCs
1 in 35,000
risk of bacterial contamination from platelets
1 in 15,000
antibodies contained in O blood
anti-A
anti-B
what causes a hemolytic transfusion reaction
a patient receives an incompatible blood product
ABO incompatibiltiy is the most lethal
what causes a hemolytic transfusion reaction
a patient receives an incompatible blood product
ABO incompatibiltiy is the most lethal
complications of hemolytic transfusion reaction
flushing
renal failure (acute tubular necrosis)
DIC
hemodynamic instability
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
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
most common adverse reaction assoc. with transfusion
febrile transfusion reaction (non-hemolytic)
methods to maintain UOP with acute hemolytic transfusion reaction
- IVF
- 12.5-15 g mannitol
- 20-40 mg lasix
3 key signs of acute hemolytic transfusion reaction under GA
- hemoglobinuria
- hypotension
- bleeding
6 signs of acute hemolytic transfusion reaction that are masked by GA
- fever
- chills
- chest pain
- dyspnea
- nausea
- flushing
cause of febrile reactions
Pyrogenic cytokines and intracellular components are released from leukocytes in the donor blood product
treatment of febrile transfusion reaction
supportive
acetaminophen
presentation of febrile transfusion reaction
Fever, chills, headache, nausea, and malaise (hypotension, chest pain, and dyspnea are less common)
cause of allergic transfusion reaction
Foreign proteins in the donor blood product
presentation of allergic transfusion reaction
Urticaria with itching (most common) and facial swelling
treatment of allergic transfusion reaction
Supportive + antihistamines.
Minor reaction = Continue transfusion
s/s major allergic transfusion reaction
dyspnea, laryngeal edema, or hemodynamic instability)
management of major allergic transfusion reaction
stop the transfusion and treat it as anaphylaxis
what is TRALI
Transfusion Related Acute Lung Injury
Form of non-cardiogenic pulmonary edema that occurs following transfusion
most common cause of transfusion-related mortality in US
TRALI
cause of TRALI
HLA & neutrophil antibodies in donor plasma
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
recipient patient populations at higher risk of TRALI
- critically ill (highest risk)
- anyone susceptible to acute lung injuries (sepsis, burns, post-CPB)
blood products with highest risk of TRALI
FFP
platelets
donor groups at higher risk for TRALI
- multiparous women (highest)
- hx blood transfusion
- hx organ transplant
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)
management of TRALI
- Maximize PEEP
- Low tidal volume
- Avoid overhydration
what is TACO
Transfusion Related Circulatory Overload
State of volume overload caused by expanding the plasma volume beyond patient’s compensatory ability
s/s TACO
- pulmonary edema
- hypervolemia
- LV dysfunction
- mitral regurg 2/2 volume overload
- ↑ PAOP
- ↑ BNP
consequences of massive transfusion
- alkalosis
- hypothermia
- hyperglycemia
- hypocalcemia
- hyperkalemia
why is massive transfusion assoc with alkalosis
citrate metabolism to bicarb in liver
why is massive transfusion assoc with hypothermia
transfusion of cold blood
why is massive transfusion assoc with hyperglycemia
dextrose additive to stored blood
why is massive transfusion assoc with hypocalcemia
binding of calcium by citrate
why is massive transfusion assoc with hyperkalemia
admin of older blood
s/s heart failure from TACO
- orthopnea
- cyanosis
- tachycardia
- HTN
- pulm edema
hallmark of heart failure with TACO
resp distress d/t pulmomary edema
hallmark of heart failure with TACO
resp distress d/t pulmomary edema
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
lethal triad of trauma
1) Acidosis
2) Hypothermia
3) Coagulopathy
how to reduce risk of hyperkalemia with RBC admin
admin. washed or fresh cells that are < 7 days old
why is acidosis assoc with trauma
- Hypoperfusion & hypoxemia reduce O2 delivery
- Body converts from aerobic to anaerobic metabolism = lactic acidosis
why is trauma assoc with hypothermia
Hemorrhage and hypoperfusion impair the body’s ability to regulate heat
why is trauma assoc with coagulopathy
- Coagulation is an enzymatic process - impaired by hypothermia
- acidosis also impairs enzymatic structures
- massive volume causes dilutional coagulopathy
at what temp are PT and PTT prolonged
< 34 deg C
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
also indicated for patients with pre-existing anemia or those that refuse allogeneic blood products, such as Jehovah’s Witnesses.
how is intraoperative blood salvage performed
- blood loss collected by dedicated device
- filtered & centrifuged
- concentrated & washed
- diluted with NS to final Hct 60-70%
- ready to be transfused
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
consequence of transfusing a large volume of salvaged blood
dilutional coagulopathy
Platelets and coagulation factors are not returned to the patient
consequence of transfusing a large volume of salvaged blood
dilutional coagulopathy
Platelets and coagulation factors are not returned to the patient
risks of using salvaged blood
Contamination of collected blood by urine, feces, amniotic fluid, or malignant cells
* Fever
* Non-immunogenic hemolysis
(rare)
risks of using salvaged blood
Contamination of collected blood by urine, feces, amniotic fluid, or malignant cells
* Fever
* Non-immunogenic hemolysis
(rare)
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
why is salvaged blood use controversial in c sections
theoretical risk of anaphylactoid syndrome of pregnancy/AFE
s/s citrate toxicity from blood transfusions
- hypocalcemia
- hypotension
- longer QT
estimating hgb based on hct
hgb can be estimated to be 1/3 of hct