(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- When extracting blood from a patient with IV, the first 5mL of blood withdrawn should be discarded.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 don’t need to use reagents)
- reduced handling of biological materials
Computer crossmatch
Elimination of false reactions associated with the ___________ crossmatch
Immediate spin
What a good RMT does in the event that there is no current file on the patient:
a. collect a current specimen and perform ABO / Rh typing once and antibody screen tests and log it into the system.
b. Test the current sample twice
c. both
d. neither
b.
2 patient data is
required, so if there’s no previous file you should test the
sample twice
If there are two computer files for the patient:
a. determine any ABO / Rh discrepancies
b. check for positive antibody screening or history of clinically significant antibodies
c. both
d. neither
c
PRETRANSFUSION FOR SPECIAL CASES : INTRAUTERINE TRANSFUSION
blood and Rh type used if the blood group is unknown
O negative
PRETRANSFUSION FOR SPECIAL CASES : INTRAUTERINE TRANSFUSION
blood type that will be provided if there’s no fetomaternal ABO or Rh incompatibility
type specific blood
PRETRANSFUSION FOR SPECIAL CASES : INTRAUTERINE TRANSFUSION
sample used:
a. serum / plasma from mother
b. red cells from mother
c. both
d. neither
a
a) Serum or plasma from the mother
b) Sample from fetus (through amniocentesis, chorionic
villus, or umbilical cord sampling)
In intrauterine transfusion, blood is usually injected from
the _________ and is done with the guide of a __________
In intrauterine transfusion, blood is usually injected from
the umbilical cord and is done with the guide of a
sonography (ultrasound guided)
PRETRANSFUSION FOR SPECIAL CASES : Neonatal Transfusion
T or F
- Blood transfused should be compatible with the infant’s blood if they are 6 months old
- Both forward and reverse typing may be done with the baby’s sample
- ABO Rh type specific blood may be given as long as there
is no indication of HDN due to ABO incompatibility - If there is circulating maternal Anti-A or Anti-B, transfuse
with Type O blood after crossmatching
- T
(if less than 4 months, blood should be compatible with maternal blood) - F (forward only)
- T
- F (NO CROSSMATCHING REQUIRED)
PRETRANSFUSION FOR SPECIAL CASES : Neonatal Transfusion
samples used for crossmatching
a. maternal red cells
b. infant’s red cells
c. both
d. neither
d. neither
(maternal’s serum or infant’s serum)
PRETRANSFUSION FOR SPECIAL CASES : Neonatal Transfusion
Frequency of testing:
○ Crossmatching done ____ per admission
○ Repeat testing if transfused with ____ antibody
screening OR transfused with ____ incompatible
blood (non-type specific blood)
Frequency of testing:
○ Crossmatching done ONCE per admission
○ Repeat testing if transfused with POSITIVE antibody
screening OR transfused with ABO-Rh incompatible
blood (non-type specific blood)
COMPATIBILITY TESTS
Infant’s serum is used especially in these 2 cases:
- no maternal specimen available
- mother has clinically insignificant antibodies
What routine compatibility tests are performed for infants once per admission?
a) ABO, Rh, and hemoglobin levels
b) ABO, Rh, and antibody screen
c) ABO, Rh, and platelet count
d) ABO, Rh, and white blood cell count
b) ABO, Rh, and antibody screen
When should the infant’s serum be used instead of maternal serum for antibody screening?
a) When no maternal specimen is available
b) When the mother has clinically insignificant antibodies
c) Both a and b
d) Never, only maternal serum should be used
c) Both a and b
Why must an indirect antiglobulin test (IAT) using infant serum and A₁ or B cells be performed?
a) To check for minor blood infections
b) To confirm the presence of Rh factor
c) If non-group O cells will be transfused
d) To determine platelet compatibility
c) If non-group O cells will be transfused
When should compatibility tests be repeated every three days?
a) When ABO- or Rh-incompatible units are transfused
b) When antibody screening shows unexpected antibodies
c) Both a and b
d) No need to repeat tests once done
c) Both a and b
Massive transfusion
Is an infusion of ____ of whole blood within 24 hours of a
blood volume exceeding the recipient’s total blood volume
OR transfusion of ____ RBCs units within 1 hour
Is an infusion of **8 to 10 units **of whole blood within 24 hours of a
blood volume exceeding the recipient’s total blood volume
OR transfusion of 4 to 5 RBCs units within 1 hour
T or F
- RBCs transfusion and other componenta are equally important
- RBCs and IV solutions may replace clotting factors or platelets, taknig into consideration dilutional coagulopathy
- massively bleeding patients are provided with 4 units of type specific negative RBCs, 4 AB FFP, and 1 AB platelet.
- Crossmatching is not necessary in massive transfusions.
- T
- F ( Giving RBCs and IV solutions will not replace clotting factors or platelets. Must take into consideration dilutional coagulopathy” )
- F (4 units group O negative RBCs, 4 AB FFP and 1 AB platelet can be combined.)
- T
Massive transfusion
a common transfusion reaction in which pulmonary edema develops primarily due to volume excess or circulatory overload.
Iatrogenic,
Transfusion-associated
circulatory
overload (TACO)
Familiarize the possible causes of Massive transfusion
- Unexpected surgical or medical emergencies
- Planned circumstances in cardiac or vascular surgery
- Exchange transfusion in an infant or adult
Massive transfusion
Test required
a. ABO
b. Crossmatching
c. both
d. neither
a
TRANSFUSION AFTER NON-GROUP SPECIFIC
TRANSFUSION
How do you switch from the nontype specific blood to the actual blood type of the patient?
ASAP:
a. ABO
b. Rh negative
c. Rh positive
d. A and C
e. B and C
d. switch to ABO type specific and Rh positive as soon as possible
If patient is Rh negative, continue to provide them with Rh negative blood
LABELING AND RELEASE OF BLOOD
- ____ process in pretransfusion compatibility testing before releasing the unit of blood equally important with other processes.
- A ____ must exist to confirm that all of the following are in aggreement : Identifying information, request, records, blood or components
- Every ____ in transfusion should be observed
- Jot down time the transfusion ____, if the transfusion was stopped before transfusing the whole unit and indicate it in the ____ with the reason of doing so.
- All discrepancies must be resolved before _____.
- Last process in pretransfusion compatibility testing before releasing the unit of blood equally important with other processes.
- A process must exist to confirm that all of the following are in agreement:
- Every 15 minutes in transfusion should also be observed and recorded.
- Jot down time the transfusion ended, if the transfusion was stopped before transfusing the whole unit and indicate it in the BTR form with the reason of doing so.
- All discrepancies must be resolved before issue
Prior to issuing the blood, blood bank personel must:
- Check the ____ of the blood to avoid issuing an outdated component
- Inspect the unit for abnormal appearance. For red cells, check for ____ or ____ on top which is a sign of bacterial contamination, or ____ plasma which is also a sign of bacterial contamination.
- Check also the bag for ____ because these may pose risk for contamination.
o Remember that your blood bag is ____ so it should be intact.
- Check the expiration date of the blood to avoid issuing an outdated component
- Inspect the unit for abnormal appearance. For red cells, check for clot or hemolysis on top which is a sign of bacterial contamination, or greenish plasma which is also a sign of bacterial contamination.
- Check also the bag for leaks or nicks because these may pose risk for contamination.
o Remember that your blood bag is semi-permeable so it should be intact.
How do you document the release of blood?
- Write the ____ of the individual issuing the blood
- ____ of issue
- Name of the blood ____ or destination
- Write the name of the individual issuing the blood
- date and time of issue
- Name of the blood recipient or destination
A TRANSFUSION TAG OR LABEL MUST BE ATTACHED TO BLOOD CONTAINER INDICATING: (3)
- Recipient’s two independent identifiers
- Donor unit number
- Interpretation of compatibility testing
Release of blood in urgent situations
- In cases of deperate need for blood, the medical technologist must weigh the hazard of transfusing uncrossmatched blood agains risk of waiting for you to complete the procedure.
- If blood is released before crossmatch is completed, it must contain a statement, usually a form, signed by a physician indicating the reason why the testing procedure was waived.
- A form or waiver signed by the physician absolves the transfusion service from responsibility to issue properly labeled donor blood of an ABO compatible group
Which of these statements is / are false?
a. 1 only
b. 2 only
c. 3 only
d. 1 and 2
e. 1 and 3
e. 1 and 3
- Desperate need for blood, the physician must weigh the hazard of transfusing uncrossmatched blood against risk of waiting for you to complete the crossmatch procedure.
- A form or waiver signed by the physician does not absolve transfusion service from responsibility to issue properly labeled donor blood of an ABO compatible
group.
Release of blood in urgent situations
- Once you have released the non specific blood, you may stop with the prior compatibility testing.
- ABO / Rh typing is mandatory as you cannot rely on previous records in case there was a clerical error
- Indicate in incospicuous fashion that blood is incrossmatched or write “Crossmatching: waived” in the transfusion tag
Which of the following statements is / are true?
a. 1 only
b. 2 only
c. 3 only
d. 1 and 2
e. 1 and 3
b. 2 only
- Even if the nonspecific blood has been released, you must proceed with crossmatching in case there is an incompatibility
- Indicate in cospicuous fashion that blood is incrossmatched or write “Crossmatching: waived” in the transfusion tag
READ!!
SUMMARY: PROCEDURES PRIOR TO ISSUANCE OF
BLOOD FOR TRANSFUSION
- Positive ID of recipient and recipient’s blood sample.
- ABO Rh typing of recipient’s blood
- Antibody detection tests using the recipient’s serum or plasma.
- Comparison and review of recipient’s previous records.
- Tests on donor blood (w/ separate discussion)
- Selection of components of ABO RH type appropriate for the recipient based on the AABB guidelines.
- Performance of serological or computer crossmatch as necessary or as allowed in the institution.
- Labeling of components with recipient’s identifying information before you release the unit.
FINAL STEP FOR THE ISSUANCE OF BLOOD
- Final identification of the recipient prior to transfusion tests with the ____. They must identify the patient and donor unit and certify that identifying forms, tags, and labels are in agreement.
- The blood bag, label, and the transfusion tag should be checked very well against the blood ____ we released, the result of the ____, and the patient’s ID.
- Transfusion is an ____ that carries potential benefits and risks to the recipient.
- Final identification of the recipient prior to transfusion tests with the transfusionist. They must identify the patient and donor unit and certify that identifying forms, tags, and labels are in agreement.
- The blood bag, label, and the transfusion tag should be checked very well against the blood transfusion records (BTR) we released, the result of the crossmatching, and the patient’s ID.
- Transfusion is an IRREVERSIBLE EVENT that carries potential benefits and risks to the recipient.
