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 the Confirming sample identity in the

laboratorylaboratory

Blood sampleBlood sample Appearance of the sampleAppearance of the sample

Serum normal, hemolysis, tubidity, or Serum normal, hemolysis, tubidity, or lipemic lipemic

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 cell Confirmation of ABO group of red cell

componentscomponents Confirmation of Rh type of Rh negative red Confirmation of Rh type of Rh negative red

cell components cell components RBC antibody detection RBC antibody detection

ProceduresProcedures

Comparison with previous records Comparison with previous records Selection of components of ABO and Selection 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 the Labeling 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 recipients2. Detecting unexpected antibodies to2. Detecting unexpected antibodies to red cell antigensred cell antigens3. Reading and interpreting reactions3. Reading and interpreting reactions4. Autologous control4. Autologous control5. Practical consideration5. Practical consideration6. Comparison with previous records6. Comparison with previous records

Serologic testingSerologic testingABO groupingABO grouping

ABO typing: both cell and serum ABO typing: both cell and serum groupinggrouping

Any discrepant results should be Any discrepant results should be resolved before blood is given.resolved before blood is given.

If transfusion is necessary before If transfusion is necessary before resolution, the patient should receive resolution, the patient should receive group O red cells.group O red cells.

Serologic testingSerologic testingRh typingRh typing

Patients’ red cells must be tested Patients’ 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 problem negative blood until the problem has been resolvedhas been resolved..

Serologic testingSerologic testing Detecting unexpected antibodies to red Detecting 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 sufficient The method chosen should have sufficient

sensitivity to detect very low levels of sensitivity to detect very low levels of antibody.antibody.

Serologic testingSerologic testing 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.

Serologic testingSerologic testingAutologous controlAutologous control

This may be useful to identify This may be useful to identify patients with auto-antibodies.patients with auto-antibodies.

Sometimes it causes difficulty in Sometimes it causes difficulty in finding a compatible blood unit.finding a compatible blood unit.

Serologic testingSerologic testing Practical considerationPractical consideration

Antibody detection tests may be performed in Antibody detection tests may be performed in advance of, or together with, a crossmatch.advance of, or together with, a crossmatch.

Performing Ab detection tests before Performing Ab detection tests before crossmatching permits early recognition and crossmatching permits early recognition and identification of clinically significant identification of clinically significant antibodies.antibodies.

Allows for the selection of the appropriate Allows for the selection of the appropriate crossmatch procedure and acquisition of units crossmatch procedure and acquisition of units with special antigen blood types.with special antigen blood types.

Serologic testingSerologic testing Comparison with previous recordsComparison with previous records

Results of ABO and Rh typing must be Results 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, a Unless there is an urgent need for blood, a crossmatch must be preformed for red cell crossmatch must be preformed for red cell transfusion.transfusion.

Must use the procedure to demonstrate Must use the procedure to demonstrate ABO incompatibilty and clinically ABO incompatibilty and clinically significant antibodies to red cell antigens.significant antibodies to red cell antigens.

CrossmatchingCrossmatching

Blood lacking the relevant antigens is to be Blood lacking the relevant antigens is to be selected for transfusion when a patient has selected for transfusion when a patient has clinically significant antibody identified clinically 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 of Confirm 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 not Confirmatory testing of weak D is not

requiredrequired Any discrepancies are to be resolved Any 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

ProceduresProcedures Donor RBCs used for crossmatching must Donor RBCs used for crossmatching must

be obtained from a segment of tubing be obtained from a segment of tubing originally attached to the blood container.originally attached to the blood container.

The cell must be washed and resuspended The cell must be washed and resuspended to 2% to 5% in saline.to 2% to 5% in saline.

The immediate spin saline technique is The immediate spin saline technique is designed to detect ABO incompatibilities designed 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 screen An ABO and Rh type and an antibody screen

and antibody identification are done when the and antibody identification are done when the patient is admitted.patient is admitted.

Blood bank must have enough donor blood Blood bank must have enough donor blood available.available.

Only testing necessary if low probability of Only testing necessary if low probability of transfusion.transfusion.

Type and ScreenType and Screen (T&S)(T&S) ABO and Rh compatible blood can be safely ABO and Rh compatible blood can be safely

released after an immediate-spin or computer released 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, the If the antibody screen is positive, the antibodies must be indentified and antigen antibodies 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 antibody Includes an ABO and Rh type and antibody screen and antibody identification. screen and antibody identification.

In addition includes a crossmatch where In addition includes a crossmatch where specific units of blood are held back for up to specific 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 the Blood is used more efficiently when the number of units set aside for a particular number 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 good When 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 are A standard number of units of RBCs are

crossmatched for a specific surgical crossmatched for a specific surgical procedure, based on average use in an procedure, based on average use in an institution.institution.

Examples Examples angioplasty angioplasty T&ST&S aortic dissectionaortic dissection T&C T&C 66 ASD repair ASD repair T&CT&C 2 2

Compatibility testing for neonates Compatibility testing for neonates less than 4 months of ageless than 4 months of age

Obtain pre-transfusion specimen from the Obtain 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 mother Serum from either the infant or the mother

may be used to detect unexpected red cell may be used to detect unexpected red cell antibodies and for crossmatchingantibodies and for crossmatching..

Compatibility testing for neonates Compatibility testing for neonates less than 4 months of ageless than 4 months of age

No need to test the infant’s serum for ABO No need to test the infant’s serum for ABO antibodies unless a non-group O infant is to antibodies unless a non-group O infant is to receive non-group O cells that are receive non-group O cells that are incompatible with passively acquired anti-A incompatible with passively acquired anti-A or anti-B.or anti-B.

If no clinically significant unexpected If no clinically significant unexpected antibodies are present, it is unnecessary to antibodies are present, it is unnecessary to crossmatch donor red cells for the initial or crossmatch donor red cells for the initial or subsequent transfusions.subsequent transfusions.

Interpretation of antibody Interpretation of antibody screening and crossmatch resultsscreening and crossmatch results

Negative results indicate only there is no Negative results indicate only there is no antibody in the patient serum that is antibody in the patient serum that is specific to donor RBC antigen.specific to donor RBC antigen.

Negative Ab screen does not guarantee the Negative Ab screen does not guarantee the the serum does not have clinically the serum does not have clinically significant RBC antibodies only that ie significant RBC antibodies only that ie contains no antibodies that react with the contains no antibodies that react with the screening cells.screening cells.

Interpretation of antibody screening Interpretation of antibody screening and crossmatch resultsand crossmatch results

Compatible crossmatch does not guarantee Compatible crossmatch does not guarantee normal red cell survival.normal red cell survival.

The cause of serologic reaction should be The cause of serologic reaction should be identified before transfusion.identified before transfusion.

If the patient is found to have clinically If the patient is found to have clinically significant antibodies, units issued for significant antibodies, units issued for transfusion should be nonreactive for such transfusion should be nonreactive for such antigen when tested with licensed reagentsantigen when tested with licensed reagents . .

Labeling and release of crossmatched Labeling and release of crossmatched blood at the time of issueblood at the time of issue

A tag or label indicating recipient’s A tag or label indicating recipient’s identification , donor unit number and identification , donor unit number and compatibility test interpretation.compatibility test interpretation.

There must be a process to confirm that the There must be a process to confirm that the identifying information, the request, the identifying information, the request, the records and the blood or component are in records and the blood or component are in agreement and that discrepancies have been agreement and that discrepancies have been resolved before issue. resolved before issue.

Selection of other componentsSelection of other components ABO compatibilityABO compatibility

Use ABO identical Use ABO identical Component to be transfused must be Component to be transfused must be

ABO compatible with the recipient’s ABO 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 Basis Blood used on Emergency Basis For a patient that is bleeding out For 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 unexpected Recipient may have an unexpected

antibodyantibody Still need to complete the crossmatch Still need to complete the crossmatch

Massive transfusionMassive transfusion Infusion of a volume of blood Infusion of a volume of blood

approximating the recipient’s total blood approximating the recipient’s total blood volume within 24 hours.volume within 24 hours.

The pre-transfusion sample no longer The pre-transfusion sample no longer represents the blood currently in the represents the blood currently in the patient’s circulation.patient’s circulation.

Important to confirm ABO compatibility of Important to confirm ABO compatibility of units administered subsequentlyunits administered subsequently. .

Blood administered after non-group Blood administered after non-group specific transfusionspecific transfusion

In most cases, the sample is tested and units In most cases, the sample is tested and units of that ABO group are issued for transfusion of that ABO group are issued for transfusion without concern for anti-A and anti-B without concern for anti-A and anti-B remaining from the initial emergency release remaining from the initial emergency release units units

Blood administered after non-group Blood administered after non-group specific transfusionspecific transfusion

When large volumes of red cells are When large volumes of red cells are transfused or when young children or infants transfused or when young children or infants receive transfusions passively acquired ABO receive transfusions passively acquired ABO antibodies may be detected.antibodies may be detected.

If crossmatch is incompatible because of If crossmatch is incompatible because of ABO antibodies, transfusion with red cells of ABO antibodies, transfusion with red cells of the alternative group should be continued. the alternative group should be continued.

The end!!The end!!

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