Transcript Hemat8-Tranfusion Medicine

Blood Transfusion Review
Salwa Hindawi
Medical Director of Blood Transfusion Services
KAUH
6th year Medical Student
Donor
Patient
The risks associated with transfusion can be reduced by:
- Effective blood donor selection.
- Screening for TTI in the blood donor population.
high quality blood grouping, compatibility testing.
- Component separation and storage.
- Appropriate clinical use of blood and blood products.
- Quality assurance
6th year Medical Student
Blood Donation
• WB every 8 weeks, Hct > 38%
• Plateletpheresis every 3 days or 24 times
per year, Hct > 38%
• Autologous Blood
– WB every 3 days
– up to 3 days prior to surgery
– Hct > 33%
6th year Medical Student
Steps in Blood Banking
• Type and Screen (T & S): (Done for low
probability of transfusion)
– ABO and Rh type
– Antibody screen
– Antibody identification
– DAT
• Type and Crossmatch (T & C) (Done for high
probability of transfusion)
• above steps plus Crossmatch
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Direct Antiglobulin Test
(DAT)
• also called the direct Coombs test
• adding anti-IgG to detect IgG that is
attached to the RBCs
• also detects C3 complement fragments on
the RBC surface
• DAT is performed in the investigation of
immune hemolytic anemia and transfusion
reactions
6th year Medical Student
Indirect Antiglobulin Test
(IAT)
• detects free antibodies in the serum
• the IAT test is performed during the
antibody screen and antibody
identification
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Type and Screen (T & S)
• an ABO and Rh type and an antibody
screen and antibody identification are
done when the patient is admitted
• only testing necessary if low probability of
transfusion
6th year Medical Student
Antibody Screen (IAT)
• recipients serum is added to 3 test RBCs
(in test tubes 1 to 3 ) which have all of the
important RBC antigens on them
• therefore if one or more of the three
screening cells is positive then a RBC
antibody is present in the serum
• then do an antibody panel to identify the
antibody present
6th year Medical Student
Antibody Identification
(IAT)
• after the screening RBCs are positive then
do an antibody identification
• recipients’ serum is added to 10 test RBCs
in a panel (test tubes 1 to 10) which
contain all of the important antigens
• the antibody in the serum is identified
6th year Medical Student
Major Crossmatch
(Compatibility testing)
• donor RBCs (unit of blood) are tested
with recipient serum
• to detect unexpected recipient antibodies
• this checks to see if the transfusion is
compatible
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Type and Cross (T & C)
• includes an ABO and Rh type and antibody
screen and antibody identification
• in addition includes a crossmatch where
specific units of blood are held back for
up to three days for a particular patient
• for a high probability of transfusion
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Crossmatch to Transfusion ratio
(C:T ratio)
• blood is used more efficiently when the
number of units set aside for a particular
patient (crossmatched) are actually
transfused.
• when a patient does not need blood, it is
good practice to get a T& S but not a T &
C
• C:T ratio is less than 2:1
6th year Medical Student
Maximum Surgical Blood
Order Schedule (MSBOS)
• Is a guideline to order standard number of
units of RBCs to be crossmatched for a
specific surgical procedure, based on
average use in the institution
• examples
– angioplasty
T&S
– aortic dissection T&C 6
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Red cell Antigens: ABO type
• present on RBCs, GI tract and vascular
endothelium
• three alleles A, B, O, the A and B alleles code
for glycosyltransferases
• specificity of the antigen is in its terminal
sugar
– galactosamine for A
– galactose for B
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ABO type continued
•
•
•
•
•
•
•
Pt Cells
Pt Serum
vs
vs
anti -A anti-B
A cells
A
+
0
0
+
B
0
+
+
0
AB
+
+
0
0
0
0
0
+
+
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B cells
40%
11%
4%
45%
Rh Type
• Five important antigens of the Rh system are D,
C, E, c, and e
• These antigens are product of two genes RHD
and RHCE located on chromosome 1p36
• These one set of three D/d C/c and E/e is
inherited from each parent
• example father CDe and mother cde then the
genotype is CcDdee and the phenotype is CcDe
6th year Medical Student
Rh type
• Rh blood group antigens are present only on
RBCs
• Rh positive means that the D antigen is present
(85% on the population)
• Rh negative means that the D antigen is absent
(15% of the population)
• the D antigen is highly immunogenic
• More than 80% of D negative persons receiving
D positive blood are expected to develop anti-D
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Hemolytic Disease of the
Newborn(HDN)
• D antigen is the most important cause of HDN
• mother is D neg, father is D pos and fetus is D positive
• fetus’ D positive RBCs enter mother’s circulation and mother
makes anti-D of IgG type which crosses the placenta
• first pregnancy not affected
• Maternal IgG crosses the placenta and affects the second D
positive pregnancy
• anti-D formation in mother prevented with Rhogam
6th year Medical Student
Other Blood Group Systems
• clinically significant blood group systems
are Kell (K), Kidd (Jk), Duffy (Fy) and Rh
(E,e,C,c) systems.
• antibodies are made by people who lack
the antigen on their RBCs
• and have been exposed to RBCs containing
the antigen
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Other Blood Group Systems
• The following are not clinically significant:
–
–
–
–
–
–
I
Le
M
N
H
P
I
Lewis
love
my
new
honda
prelude
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Blood Used on Emergency
Basis
• Blood used on Emergency Basis
– for a patient that is bleeding out
– and the blood type is unknown
• group O, Rh negative, uncrossmatched
• recipient may have an unexpected
antibody
• after 5 min use ABO and Rh type specific
blood
6th year Medical Student
Whole Blood
• 450 ml of whole blood with 63 ml of
anticoagulant
• need for oxygen carrying capacity and volume
replacement
• no viable platelets or WBC
• decreased labile coagulation factors (Factor V
and VIII)
• Not available since it is not efficient utilization
of blood
6th year Medical Student
Packed Red Blood Cells
(PRBCs)
• 200-250 ml of RBCs and 50 ml of plasma
• Hematocrit 55-70% depending on
anticoagulant
• shelf life 35 to 42 days depending on the
anticoagulant
• treatment of symptomatic anemia where
oxygen carrying capacity is needed
6th year Medical Student
Leukocyte Reduced RBCs
• RBCs with 99.99% of WBCs removed by
leukocyte reduction filter
• prevents repeated nonhemolytic febrile
transfusion reactions
• reduces immunosuppression of recipient by
donor WBC
• decreases post-operative surgical infections
due to reduced immunosuppression
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Leukocyte Reduced RBCs
continued
• prevents or delays HLA alloimmunization
• identical to CMV seronegative blood
• does not prevent graft versus host
disease, only gamma irradiation prevents
graft versus host disease
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Indications for Leukocyte
Reduced RBC continued
• after second nonhemolytic febrile
transfusion reaction
• newly diagnosed leukemics
• long term multiple transfused patients
– sickle cell disease
– aplastic anemia
– thalassemia
6th year Medical Student
Frozen RBCs
• store RBCs for up to 10 years at -70C in
glycerol
• glycerol is a cryopreservative solution
• used for
– rare blood types for patients with multiple
antibodies
– autologous blood for a postponed operation
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(Gamma) Irradiated RBCs
• RBCs and platelets are exposed to gamma
irradiation at 2500 rads for 4.5 minutes
• this inactivates the T lymphocytes in the
donor unit and prevents graft versus host
disease in an immunocompromised
recipient
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Indications for Gamma
Irradiated RBCs
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•
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•
•
bone marrow transplant recipients
congenital immunodeficiency syndromes
intrauterine transfusions
transfusions from all blood relatives
Hodgkin’s disease
WBC products (to neutropenic patient)
– (never Stem Cells)
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Plateletpheresis
• donated by a single donor
• 3.0 x 10 E11 platelets plus 300 ml of
plasma, expires after 5 days
• raises the platelet count 30,000
• used for all platelet transfusions until less
than 10,000 platelet increase
6th year Medical Student
Pooled Platelets
• are prepared from the platelet portion of 6
whole blood units plus 300 ml of plasma
(potential for 6 infectious disease
exposures) expires after 5 days
• 6 X 5 X 10 E10 = 3.0 x 10 E 11 platelets
• 6 x 5000 rise /RD plt = 30,000
• transfuse the patient with platelets from
many donors to see which platelets will raise
the platelet count
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Indications for Platelets
• low platelet count or functional
abnormality
• major bleed, major surgery >100,000
• minor bleed, minor procedure >50,000
• prevent spontaneous bleed > 10,000
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Low Post-transfusion
Increment to Platelets
• 1 hour post (platelet recovery) poor
– platelet alloantibodies
– platelet autoantibodies
– hepatosplenomegaly
• 24 hour post (platelet survival) poor
– infection
– DIC
bleeding
fever
6th year Medical Student
Fresh Frozen Plasma (FFP)
• 200-250 ml of plasma frozen at -18C
within 8 hours of collection
• no platelets are present
• contains all coagulation factors
• an unconcentrated source of fibrinogen
– use Cryo to correct a low fibrinogen level
• needs 20-30 min lead time to thaw prior
to use
6th year Medical Student
FFP Continued
• used in patients with multiple coagulation
factor deficiencies:
– liver disease
– DIC
– massive transfusion
• indicated when PT/PTT are >17/55 sec
• not used if non bleeding or for volume
replacement
6th year Medical Student
Cryoprecipitate (Cryo)
• a white precipitate that forms when FFP
at -18C is thawed to 4C
• volume is 10 to 15 ml
• adult dose is 10 to 20 pooled units
• 30 minutes is needed for thawing and
pooling
6th year Medical Student
Cryoprecipitate continued
• Cryoprecipitate can be used for the
replacement of all of the following:
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–
–
–
vWF
Factor VIII
Factor XIII
Fibrinogen
vWD
Hemoplilia A
Factor XIII def
dec. fibrinogen *
• head injury, massive bleed, trauma,
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Complications of Blood Transfusion
Immediate
HTR
FNTR
TRALI
Bacterial
contamination
Allergic, Anaphylaxis
Delayed
GVHD
PTP
Iron overload
Infectious
diseases
Alloimmunization
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Transfusion Transmitted
Disease (TTD)
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•
•
•
•
•
HBV
HCV
HTLV-I
HTLV-II
HIV-1
HIV-2
1 in 63,000
1 in 103,000
1 in 641,000
1 in 641,000
1 in 587,000
< 1 in 1,000,000
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Acute Hemolytic
Transfusion Reaction
• a clerical error (wrong specimen, wrong
patient)
• 1 in 6,000 to 25,000 transfusions
• back pain, chest pain, fever, red urine,
oliguria, shock, DIC, death in 1 in 4
• stop the transfusion
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Work up of An AHTR
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start normal saline
treat patient symptomatically
send blood bag and tubing to culture
send red top and purple top tubes
urine specimen for hemoglobinuria
DAT is positive
6th year Medical Student
Non Hemolytic Febrile
Transfusion Reaction
• NHFTR
(1:100)
• Recipient has WBC antibodies to Donor
WBCs contained within RBCs and
Plateletpheresis products
• DAT is negative
• rise in temperature by 2F or 1C
• other causes for fever are eliminated
6th year Medical Student
Allergic (Urticarial) Transfusion
Reaction
• Recipient has antibodies to the Donor’s
plasma proteins (1 in 1000)
• offending protein is not identified
• urticaria, itching, flushing, wheezing
• this is the only transfusion reaction where
the blood that is hanging can be restarted
after treatment with Benadryl
• if symptoms continue then STOP
6th year Medical Student
Anaphlyactic Transfusion
Reaction
• anaphylactic reaction (1 in 150,000)
• 1 in 700-900 people never made IgA
• occurs when exposed to normal blood
products which contain IgA
• bronchospasm, vomiting and diarrhea and
vascular collapse
• treat with Epinepherine, Solu-Medrol,
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Circulatory Overload
• marginal cardiovascular status
• given blood components too rapidly
• develops acute shortness of breath, heart
failure, edema (1: 10,000)
• systolic BP increases 50 mm
• infuse slowly, not to exceed 4 hours
• split the unit of RBC and give half
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Transfusion Related Acute
Leukocyte Lung Injury
• TRALI reaction (1:10,000)
• Donor plasma contains WBC antibodies
that when transfused to the recipient
cause agglutination of recipient’s WBC in
the pulmonary capillary beds
• Chest X ray looks like ARDS
• Donor removed from donating blood
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Sepsis from Bacterial
Comtamination
• Platelets:
– skin contaminants most common cause
– plateletpheresis 1 in 5000
– pooled platelets 1 in 1000
• RBC:
– Sepsis from RBC due to Yersinia,
Enterics or Gram Positive 1 in 3,000,000
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6th year Medical Student