Pre transfusion testing, dr. rafiq

Pre-transfusion TestingPre-transfusion Testing
DR. RAFIQ AHMADDR. RAFIQ AHMAD

Transfusion requestsTransfusion requests
 Patient identificationPatient identification
 HN, Name, Date of birth, Gender, Age,HN, Name, Date of birth, Gender, Age,
DiagnosisDiagnosis
 Type and number of unit of componentType and number of unit of component
requestedrequested
 Physician’s NamePhysician’s Name
 Sample labelingSample labeling
 Confirming sample identity in theConfirming sample identity in the
laboratorylaboratory

Blood sampleBlood sample
 Appearance of the sampleAppearance of the sample
 Serum normal, hemolysis, tubidity, orSerum normal, hemolysis, tubidity, or
lipemiclipemic
 Age of sampleAge of sample
 Should not more than 3 days oldShould not more than 3 days old
 Retaining and storing blood samplesRetaining and storing blood samples
 Kept at least 7 daysKept at least 7 days

ProceduresProcedures
After proper identification of recipientAfter proper identification of recipient
and recipient’s blood sample.and recipient’s blood sample.
 ABO and Rh typingABO and Rh typing
 Confirmation of ABO group of red cellConfirmation of ABO group of red cell
componentscomponents
 Confirmation of Rh type of Rh negative redConfirmation of Rh type of Rh negative red
cell componentscell components
 RBC antibody detectionRBC antibody detection

 Comparison with previous recordsComparison with previous records
 Selection of components of ABO andSelection of components of ABO and
Rh types appropriate for the recipientRh types appropriate for the recipient
 Performance of a serologic (tube/gel)Performance of a serologic (tube/gel)
 Labeling of products with theLabeling of products with the
recipient’s identifying informationrecipient’s identifying information

Serologic testingSerologic testing
1. ABO and Rh typing of the recipients1. ABO and Rh typing of the recipients
2. Detecting unexpected antibodies to2. Detecting unexpected antibodies to
red cell antigensred cell antigens
3. Reading and interpreting reactions3. Reading and interpreting reactions
4. Autologous control4. Autologous control
5. Practical consideration5. Practical consideration
6. Comparison with previous records6. Comparison with previous records

ABO groupingABO grouping
 ABO typing: both cell and serumABO typing: both cell and serum
groupinggrouping
 Any discrepant results should beAny discrepant results should be
resolved before blood is given.resolved before blood is given.
 If transfusion is necessary beforeIf transfusion is necessary before
resolution, the patient should receiveresolution, the patient should receive
group O red cells.group O red cells.

Rh typingRh typing
 Patients’ red cells must be testedPatients’ red cells must be tested
with anti-D.with anti-D.
 If problems with D typing arise,If problems with D typing arise,
the patient should be given Rh-the patient should be given Rh-
negative blood until the problemnegative blood until the problem
has been resolvedhas been resolved..

Detecting unexpected antibodies to redDetecting unexpected antibodies to red
cell antigenscell antigens
 To detect clinically significant antibodiesTo detect clinically significant antibodies
 Use unpooled reagent red cellsUse unpooled reagent red cells
 Include antiglobulin testInclude antiglobulin test
 Use of Coombs’ control cellsUse of Coombs’ control cells
 The method chosen should have sufficientThe method chosen should have sufficient
sensitivity to detect very low levels ofsensitivity to detect very low levels of
antibody.antibody.

Reading and interpreting reactionsReading and interpreting reactions
 Hemolysis and agglutination must beHemolysis and agglutination must be
observed accurately and consistently.observed accurately and consistently.
 The results must be recorded immediatelyThe results must be recorded immediately
after reading.after reading.
 All personnel in the laboratory must use theAll personnel in the laboratory must use the
same interpretation and notations.same interpretation and notations.

Autologous controlAutologous control
 This may be useful to identifyThis may be useful to identify
patients with auto-antibodies.patients with auto-antibodies.
 Sometimes it causes difficulty inSometimes it causes difficulty in
finding a compatible blood unit.finding a compatible blood unit.

Practical considerationPractical consideration
 Antibody detection tests may be performed inAntibody detection tests may be performed in
advance of, or together with, a crossmatch.advance of, or together with, a crossmatch.
 Performing Ab detection tests beforePerforming Ab detection tests before
crossmatching permits early recognition andcrossmatching permits early recognition and
identification of clinically significantidentification of clinically significant
antibodies.antibodies.
 Allows for the selection of the appropriateAllows for the selection of the appropriate
crossmatch procedure and acquisition of unitscrossmatch procedure and acquisition of units
with special antigen blood types.with special antigen blood types.

Comparison with previous recordsComparison with previous records
 Results of ABO and Rh typing must beResults of ABO and Rh typing must be
compared with previous transfusion records.compared with previous transfusion records.
 The comparison must be documentedThe comparison must be documented
 Review the records forReview the records for
 Clinically significant red cell antibodiesClinically significant red cell antibodies
 Difficulties in testingDifficulties in testing
 Occurrence of significant adverse recationsOccurrence of significant adverse recations
 Special transfusion requirementSpecial transfusion requirement

CrossmatchingCrossmatching
 Unless there is an urgent need for blood, aUnless there is an urgent need for blood, a
crossmatch must be preformed for red cellcrossmatch must be preformed for red cell
transfusion.transfusion.
 Must use the procedure to demonstrateMust use the procedure to demonstrate
ABO incompatibilty and clinicallyABO incompatibilty and clinically
significant antibodies to red cell antigens.significant antibodies to red cell antigens.

CrossmatchingCrossmatching
 Blood lacking the relevant antigens is to beBlood lacking the relevant antigens is to be
selected for transfusion when a patient hasselected for transfusion when a patient has
clinically significant antibody identifiedclinically significant antibody identified
currently and historically.currently and historically.
 Shall include the antiglobulin testShall include the antiglobulin test

Repeat testing of donor bloodRepeat testing of donor blood
 Confirm the ABO group of all units ofConfirm the ABO group of all units of
RBCsRBCs
 Rh typing of RBC units labeled as Rh-Rh typing of RBC units labeled as Rh-
negativenegative
 Confirmatory testing of weak D is notConfirmatory testing of weak D is not
requiredrequired
 Any discrepancies are to be resolvedAny discrepancies are to be resolved
before the unit is issued for transfusionbefore the unit is issued for transfusion

CrossmatchCrossmatch
 Major crossmatch – recipient serum + donor red cells
o Detects recipient antibodies against donor
antigens
o Final check on ABO compatibility
 Minor crossmatch – recipient red cells + donor
serum – not
required by AABB and not recommended
 Done in 3 phases – with some variations
o Room temperature
o 37 °C incubation
o Antihumanglobulin phase
 An autocontrol is also usually run with
the crossmatch

 Donor RBCs used for crossmatching mustDonor RBCs used for crossmatching must
be obtained from a segment of tubingbe obtained from a segment of tubing
originally attached to the blood container.originally attached to the blood container.
 The cell must be washed and resuspendedThe cell must be washed and resuspended
to 2% to 5% in saline.to 2% to 5% in saline.
 The immediate spin saline technique isThe immediate spin saline technique is
designed to detect ABO incompatibilitiesdesigned to detect ABO incompatibilities
between donor red cells and recipient serumbetween donor red cells and recipient serum
 Antiglobulin test must be included.Antiglobulin test must be included.

Type and Screen (T&S)Type and Screen (T&S)
 An ABO and Rh type and an antibody screenAn ABO and Rh type and an antibody screen
and antibody identification are done when theand antibody identification are done when the
patient is admitted.patient is admitted.
 Blood bank must have enough donor bloodBlood bank must have enough donor blood
available.available.
 Only testing necessary if low probability ofOnly testing necessary if low probability of
transfusion.transfusion.

Type and ScreenType and Screen (T&S)(T&S)
 ABO and Rh compatible blood can be safelyABO and Rh compatible blood can be safely
released after an immediate-spin or computerreleased after an immediate-spin or computer
crossmatch, if the antibody screen is negative.crossmatch, if the antibody screen is negative.
 If the antibody screen is positive, theIf the antibody screen is positive, the
antibodies must be indentified and antigenantibodies must be indentified and antigen
negative units must be available for used.negative units must be available for used.

Type and Cross (T & C)Type and Cross (T & C)
 Includes an ABO and Rh type and antibodyIncludes an ABO and Rh type and antibody
screen and antibody identification.screen and antibody identification.
 In addition includes a crossmatch whereIn addition includes a crossmatch where
specific units of blood are held back for up tospecific units of blood are held back for up to
three days for a particular patient.three days for a particular patient.
 For a high probability of transfusionFor a high probability of transfusion

Crossmatch to Transfusion ratioCrossmatch to Transfusion ratio
(C:T ratio)(C:T ratio)
 Blood is used more efficiently when theBlood is used more efficiently when the
number of units set aside for a particularnumber of units set aside for a particular
patient (crossmatched) are actually transfused.patient (crossmatched) are actually transfused.
 When a patient does not need blood, it is goodWhen a patient does not need blood, it is good
practice to get a T& S but not a T & Cpractice to get a T& S but not a T & C
 C:T ratio is less than 2:1C:T ratio is less than 2:1

Routine surgical blood ordersRoutine surgical blood orders
 A standard number of units of RBCs areA standard number of units of RBCs are
crossmatched for a specific surgicalcrossmatched for a specific surgical
procedure, based on average use in anprocedure, based on average use in an
institution.institution.
 ExamplesExamples
 angioplastyangioplasty T&ST&S
 aortic dissectionaortic dissection T&CT&C 66
 ASD repairASD repair T&CT&C 22

Compatibility testing for neonatesCompatibility testing for neonates
less than 4 months of ageless than 4 months of age
 Obtain pre-transfusion specimen from theObtain pre-transfusion specimen from the
infant to determine ABO and Rh typeinfant to determine ABO and Rh type
 For ABO typing, test only cell groupingFor ABO typing, test only cell grouping
 Serum from either the infant or the motherSerum from either the infant or the mother
may be used to detect unexpected red cellmay be used to detect unexpected red cell
antibodies and for crossmatchingantibodies and for crossmatching..

Compatibility testing for neonatesCompatibility testing for neonates
less than 4 months of ageless than 4 months of age
 No need to test the infant’s serum for ABONo need to test the infant’s serum for ABO
antibodies unless a non-group O infant is toantibodies unless a non-group O infant is to
receive non-group O cells that arereceive non-group O cells that are
incompatible with passively acquired anti-Aincompatible with passively acquired anti-A
or anti-B.or anti-B.
 If no clinically significant unexpectedIf no clinically significant unexpected
antibodies are present, it is unnecessary toantibodies are present, it is unnecessary to
crossmatch donor red cells for the initial orcrossmatch donor red cells for the initial or
subsequent transfusions.subsequent transfusions.

Interpretation of antibodyInterpretation of antibody
screening and crossmatch resultsscreening and crossmatch results
 Negative results indicate only there is noNegative results indicate only there is no
antibody in the patient serum that isantibody in the patient serum that is
specific to donor RBC antigen.specific to donor RBC antigen.
 Negative Ab screen does not guarantee theNegative Ab screen does not guarantee the
the serum does not have clinicallythe serum does not have clinically
significant RBC antibodies only that iesignificant RBC antibodies only that ie
contains no antibodies that react with thecontains no antibodies that react with the
screening cells.screening cells.

Interpretation of antibody screeningInterpretation of antibody screening
and crossmatch resultsand crossmatch results
 Compatible crossmatch does not guaranteeCompatible crossmatch does not guarantee
normal red cell survival.normal red cell survival.
 The cause of serologic reaction should beThe cause of serologic reaction should be
identified before transfusion.identified before transfusion.
 If the patient is found to have clinicallyIf the patient is found to have clinically
significant antibodies, units issued forsignificant antibodies, units issued for
transfusion should be nonreactive for suchtransfusion should be nonreactive for such
antigen when tested with licensed reagentsantigen when tested with licensed reagents..

Labeling and release of crossmatchedLabeling and release of crossmatched
blood at the time of issueblood at the time of issue
 A tag or label indicating recipient’sA tag or label indicating recipient’s
identification , donor unit number andidentification , donor unit number and
compatibility test interpretation.compatibility test interpretation.
 There must be a process to confirm that theThere must be a process to confirm that the
identifying information, the request, theidentifying information, the request, the
records and the blood or component are inrecords and the blood or component are in
agreement and that discrepancies have beenagreement and that discrepancies have been
resolved before issue.resolved before issue.

Selection of other componentsSelection of other components
 ABO compatibilityABO compatibility
 Use ABO identicalUse ABO identical
 Component to be transfused must beComponent to be transfused must be
ABO compatible with the recipient’sABO compatible with the recipient’s
plasma.plasma.
 Rh TypeRh Type
 Other blood groupsOther blood groups

In Case of EmergencyIn Case of Emergency
Blood used on Emergency BasisBlood used on Emergency Basis
 For a patient that is bleeding outFor a patient that is bleeding out
 Patient with unknown blood typePatient with unknown blood type
 Group O, Rh negative, uncrossmatchedGroup O, Rh negative, uncrossmatched
 Recipient may have an unexpectedRecipient may have an unexpected
antibodyantibody
 Still need to complete the crossmatchStill need to complete the crossmatch

Massive transfusionMassive transfusion
 Infusion of a volume of bloodInfusion of a volume of blood
approximating the recipient’s total bloodapproximating the recipient’s total blood
volume within 24 hours.volume within 24 hours.
 The pre-transfusion sample no longerThe pre-transfusion sample no longer
represents the blood currently in therepresents the blood currently in the
patient’s circulation.patient’s circulation.
 Important to confirm ABO compatibility ofImportant to confirm ABO compatibility of
units administered subsequentlyunits administered subsequently..

Blood administered after non-groupBlood administered after non-group
specific transfusionspecific transfusion
 In most cases, the sample is tested and unitsIn most cases, the sample is tested and units
of that ABO group are issued for transfusionof that ABO group are issued for transfusion
without concern for anti-A and anti-Bwithout concern for anti-A and anti-B
remaining from the initial emergency releaseremaining from the initial emergency release
unitsunits

Blood administered after non-groupBlood administered after non-group
specific transfusionspecific transfusion
 When large volumes of red cells areWhen large volumes of red cells are
transfused or when young children or infantstransfused or when young children or infants
receive transfusions passively acquired ABOreceive transfusions passively acquired ABO
antibodies may be detected.antibodies may be detected.
 If crossmatch is incompatible because ofIf crossmatch is incompatible because of
ABO antibodies, transfusion with red cells ofABO antibodies, transfusion with red cells of
the alternative group should be continued.the alternative group should be continued.

The end!!The end!!
Thank youThank you

Pre transfusion testing, dr. rafiq

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