(M) Pretransfusion testing and Transfusion practices Flashcards
A series of testing procedures and processes with the
ULTIMATE objective of ensuring the best possible
outcome of a blood transfusion.
Pretransfusion testing
Purpose of pretransfusion testing - T or F
To select blood components that will have 100% survival when transfused and will not cause harm to the patient
F (acceptable survival)
REMEMBER!
blood transfusion is not 100% safe
If pretransfusion testing is performed properly, it will be
able to: (2)
a) Establish ABO - Rh compatibility
b) Detect most clinically significant unexpected antibodies.
Familiarize!
Steps in pretransfusion testing
- request for transfusion
- Identification of transfusion recipient and blood specimen collected
- Testing of tranfusion recipient’s blood specimen
- Donor RBC unit testing
- Donor red cell unit selection
- compatibility testing / crossmatching
- Labelling of blood or blood components with the recipient’s identifying information and issue
What are the tests done in testing of transfusion recipient’s blood specimen:
➔ Blood specimen acceptability
➔ ABO group and Rh type
➔ Antibody detection testing
➔ Antibody identification
➔ Comparison of current and previous test results
fill in the blanks
- _____ of transfusion errors come from the preanalytical
phase of testing - The patient should have at least ___ identifiers
3-5. A major cause of transfusion-associated fatalities is due
to_________ esulting in incorrect ____
groupings and transfusion of _____ incompatible blood
- 40%
- 2
- Clerical error
- ABO
- ABO
T or F
- We may rely on patient’s charts and records for patient identification.
- Labelling of samples must be done at the bedside of the recipient
- If there is any doubt about the identity of th patient sample integrity, simply ask the phlebotomist for any clarifications.
- When extracting blood from a patient with IV, the first 5mL of blood withdrawn should be discarded.
- Before drawing blood from a patient with IV line, it must first be disconnected or stopped for 5 to 10 minutes
- F
- T
- F (new sample must be obtained)
- F (10mL)
- T
- What are the samples used for testing?
- How much blood is needed?
- Serum / plasma or RBCs either clotted or anticoagulated
samples (2 - 5% concentration) - 10mL
If the sample of patient is still hemolyzed after several blood
draws which may be due to autoimmune hemolytic anemia,
or ongoing hemolysis, just accept the hemolyzed sample
and make sure to ________________
compare the degree of hemolysis
results of a patient with an autommine hemolytic disease:
a. positive
b. negative
- the degree of hemolysis is the same from before,
during, and after testing - increasing intensity in the hemolysis of the
sample
- b
- a
What may be reagent may be added to quickly induce clotting and ensures the yield of good quality serum for testing
1 drop of thrombin
reagent
50 Units/L in every 1 mL of plasma
or
dry thrombin that will adhere
to the end of an applicator stick
What are the tools that you may use to detach the segment attached to the blood bag?
- segment puncture device
- scissors
- lancets
Samples for donor testing must be collected (before /at the same time/ after)
as the full donor unit.
at the same time
- a unique serial number that comes with each blood bag
- must be checked toroughly
Donor unit identification number
What are the five transfusion transmissible infections?
- Hepa B
- Hepa C
- HIV
- Malaria
- Syphilis
- all recipient samples for pre transfusion testing should not be older than how many hours / days?
- In the Philippines, the DOH recommends a ___ hour limit to ensure the detection of all clinically significant antibodies
3-4. After testing, according to AABB the sample used must be stored for at at least ______ after each transfusion. Carefully label and refridgerate at ________.
- 3 days or 72 hours
- 42 hour limit
- 7 days
- 1-6C
a. forward typing
b. reverse typing
c. both
d. neither
- ABO Rh typing of recipient’s blood
- ABO Rh typing of donor’s blood
- C
- A
Steps in serologic testing
- ABO Rh of recipient’s blood
- antibody detection tests
- Ab screening
- Ab identification
- crossmatching
Comparison and Review of Recipients Current and
Previous Records:
Check if the patient has previously identified an ________
and it is just falling below detectable level.
antibody
- Any discrepancies in blood typing results should be resolved before blood is given.
- If you have not identified yet what is the blood type of the patient, you cannot withhold the unit if it is an emergency and
the patient is in need of blood, the doctor may opt to give O red cells.
a. first stament is true
b. second statement is true
c. both statements are true
d. neither of the statements are true
c
- If problems in D typing arise, the patient should be
given Rh-negative blood until the problem has been
resolved. - if you cannot
determine if the
patient is Rh
positive or negative
and you do not
have the capability
to perform weak D,
then the patient
should be given
Rh positve blood
a. first stament is true
b. second statement is true
c. both statements are true
d. neither of the statements are true
a
What are the criteria for clinically significant antibodies?
o Reacts at 37°C and AHG test
o Implicated with HDN; Cause HTR, or decreased
survival of transfused RBC
Selection of RBC components
- what is the first choice?
- Rh-negative patients should always receive Rh-(positive / negative)
blood - Rh-positive blood may only be given to Rh-negative if the
patient (has / lacks) pre-formed anti-D given that : patient is male or beyond menopause
- ABO- Type specific
- Rh negative
- lacks
mandatory and routinely done for donors
a. ABO reverse typing
b. Rh-D
c. both
d. neither
b.
(ABO forward lang ang routine)
- Rh negative blood can be given to Rh-positive patients and is routinely done
- Rh-positive blood can be given to male and menopausal patients
a. first stament is true
b. second statement is true
c. both statements are true
d. neither of the statements are true
b
Rh negative can be given to Rh-positive patients BUT IT IS NOT ROUTINELY DONE because Rh negative blood is rare
Rh positive blood can be given to male and menopausal patients because there’s no risk for HDFN since they cannot / will not get pregnant
- What is the ABO requirement for Whole Blood transfusion when an ABO-identical donor is not available?
a) Must be compatible with the recipient’s plasma
b) Must be identical to the recipient
c) Any ABO group is acceptable
d) Must be compatible with the recipient’s red cells
b
For Red Blood Cells transfusion, the donor’s blood must be compatible with the recipient’s:
a) Red cells
b) Plasma
c) Whole blood type
d) Antibodies
b
What is the ABO requirement for Granulocytes Pheresis?
a) Must be identical to the recipient
b) Must be compatible with the recipient’s plasma
c) Any ABO group is acceptable
d) Must be type specific
b
Fresh Frozen Plasma (FFP) must be compatible with the recipient’s:
a) Red cells
b) Plasma
c) Whole blood type
d) Platelets
a
What is the recommended approach for selecting Platelets Pheresis components?
a) Only type-specific platelets should be used
b) Any ABO group is acceptable, but compatibility with the recipient’s red cells is preferred
c) Only O blood group platelets should be used
d) Platelets should be identical to the recipient’s blood type
b
Why is reverse typing recommended when selecting Platelets Pheresis?
a) To confirm the blood type of plasma components
b) To match the donor’s red cells with the recipient’s plasma
c) To check for the presence of antigens
d) To ensure that the donor and recipient have the same blood type
a
what is the maximum amount of red blood cells incorporated in a Platelets Pheresis unit?
a) 50 ml
b) 10 ml
c) 5 ml
d) 1 ml
c
Why is non-type specific Platelets Pheresis acceptable in some cases?
a) Because platelets do not carry antigens
b) Because the unit contains minimal red cells (maximum of 5 ml)
c) Because plasma compatibility is not necessary
d) Because platelet transfusions are universal
b
What is the ABO requirement for Cryoprecipitated AHF transfusion?
a) Must be ABO identical to the recipient
b) Must be compatible with the recipient’s plasma
c) Any ABO group is acceptable since it doesn’t have red cells
d) Must be compatible with the recipient’s red cells
c
What is the most important compatibility requirement for Whole Blood transfusion?
a) Any ABO group can be used
b) Must be identical to the recipient
c) Must be compatible with the recipient’s plasma
d) Must be compatible with the recipient’s red cells
c
What are the 2 main functions of compatibility testing
a. Initial check of ABO compatibility
b. Detect the presence of antibody present in the donor directed against recipient RBC
c. both
d. neither
d. neither
FINAL check of ABO compatibility
Detect the presence of an antibody present in the recipient directed agains an antigen on the donor RBC
That is the limitation of crossmatching?
there is no test that can guarantee the fate of a unit of blood
Compatibility testing
a. major crossmatch
b. minor crossmatch
c. both
d. neither
a
preferred by most blood blanks as it has three phases of testing
a. antiglobulin crossmatch
b. spectrum compatibility testing
c. both
d. neither
c
Only performed if the type and screen of the patient and donor are negative
abbreviated crossmatch
- Matches donor and patient ABO Rh and antibody profile
on database - Requires two (2) patient data on file:
o Maybe 1 recent and 1 old file or
o Testing patient’s submitted sample twice done by 2
different technologists.
Computer crossmatch
What are the advantages of computer crossmatch
- reduced costs (since you dont need to use reagents)
- reduced handling of biological materials
