compatibility testing blakes flashcards
Blood transfusions needed to
Recipient Identification & Sample Collection and Processing
Blood Bank Testing
Blood Type and Antibody
Compatibility Blood Selection and compatibility
Recipient Identification & Transfusion
Compatibility testing involves all the steps in the
identification and testing of a donor unit and a
proposed recipient’s blood
Crossmatching is a part of
is part of compatibility testing
Compatibility Testing
Involves mixing _________
No what or what indicates compatibility
- Involves mixing donor RBCs and recipient serum or plasma
- No agglutination or hemolysis indicates compatibility
- Agglutination or hemolysis indicates incompatibility
Crossmatching serves and provides secondary means of
- Serves as a double check of ABO errors
- Provides a second means of detecting antibodies
According to the AABB Standards, crossmatching:
- “shall use methods that demonstrate ABO incompatibility
and clinically significant antibodies to red cell antigens and
shall include an antiglobulin phase.”
IS Crossmatch
- IS crossmatching is
performed when the recipient has
no evidence of an antibody - In the current sample OR
- In the historical record
- Recipient serum and donor RBC
suspension are mixed and
immediately centrifuged - Fulfills AABB standards
for detecting ABO incompatibility
Extended crossmatch
- All phases (IS, 37° C, antihuman
globulin [AHG]) are performed if the
patient demonstrates a
clinically significant antibody - In the current sample OR
- In the historical record
- If the patient has
autoantibody, autoadsorbed serum
may be used
Causes of Positive Results in the
Serologic Crossmatch
Incorrect ABO grouping of the patient or donor
An alloantibody in the patient’s serum reacting
with the corresponding antigen on donor RBCs
An autoantibody in the patient’s serum reacting
with the corresponding antigen on donor RBCs
New alloantibody
Alloantibody to low-incidence
Warm-reactive autoantibody
Donor positive DAT
Computer
Crossmatching
(EXM)
Makes a final check of
ABO
compatibility in the selection of
units instead of a serologic IS
procedure
Computer
Crossmatching
(EXM)
The recipient must not have what
The recipient must not have an
antibody (or antibodies) in the
current sample or have a
history of antibodies
Computer
Crossmatching
(EXM)
what are used to provide anther measure of safety
Bar codes
Limitations of crossmatching
An acceptable crossmatch
does not guarantee
a successful transfusion
– Adverse transfusion
reactions may still occur
– A negative antibody screen
does not guarantee that the
recipient does not
have significant antibodies
– A compatible crossmatch
does not
Guarantee survival of RBCs
Pretransfusion Will…
If performed correctly
Verify in most
cases components are ABO
Compatible.
Detect most
clinically significant unexpected
antibodies.
Transfusion Request Form
Transfusion Request Form
can be
Can be oral, electronic or written and must include information sufficient to positively
ID patient.
Transfusion Request Form
How many identifiers required and what types
2
- Patient full name
*Unique ID number
*Other identifier
*DOB
*Driver’s license number - Photographic ID
Transfusion Request Form
what is a drug and requires what
Blood is a drug and requires physician prescription.
Transfusion Request Form
Special Needs:
CMV negative, Irradiated, etc.
Transfusion Request Form
Reject Requisition if
Information incomplete or lacking
inaccurate
Illegible
Specimens
General Patients
Expires on 3rd day at midnight
Neonates specimens
Expires at 4 months of age
Give type O RBCs
Elective Surgery Patient’s specimens
Up to 30 days prior to surgery
Restrictions:
1. No history of alloantibodies
2. No history of pregnancy or transfusion within the last 3 months
3. Negative antibody screen
Recipient Blood Sample
Patient identification and sample labeling
- Full Name, Unique ID Number, Date and Time, Phlebotomist ID
- Labeled at patient bedside
Recipient Blood Sample
Sample collection tubes
- Samples may be plasma or serum
Recipient Blood Sample
Age of sample
- The limit is 3 days if the patient has been recently transfused or is pregnant
- Infants - specimen good till neonate turns 4 months
Recipient Blood Sample
Sample collection and appearance
*Hemolyzed samples or samples contaminated with intravenous fluids must be re-collected
Recipient Blood Sample
Specimen Storage
- Sample and sample from donor RBCs must be stored at 1-6oC for 7 days AFTER transfusion.
Previous Records
Current blood ABO and D typing must be compared with
results performed over
the past 12 months
Previous Records
- SECOND sample to confirm
ABO/Rh if no history (use of PPID eliminates
need for second sample)
Previous Records
The most significant information is
history of clinically
significant antibodies
Previous Records
- Specificity compared to ______
- Regardless of current results, _________________________
- Specificity compared to current antibodies detected.
- Regardless of current results, antigen negative blood MUST be provided.