Pretransfusion Testing Flashcards
goal of pretransfusion testing
to ensure compatibility between donor product and recipient
who does the donor testing
Canadian Blood Services
recipient testing
performed by hospital transfusion service
this ensures compatibility between donor cells and patient plasma (major)
crossmatch
- ABO
- all products must be ABO compatible
step after crossmatch
allocation/ tagging
- allocate to one patient only
- unit is tagged (first, last, ULI, BBIN)
- designated for patient
- 96 hrs
issuing
- after allocation
- leaves blood blank
pretransfusion testing criteria
- informed consent
- patient ID, sample collection, labeling
- patient history
- ABO Rh
- antibody screen
- crossmatch
T or F. ABO Rh is done with every single pretransfusion testing
T
when identifying patients for pretransfusion testing …
- two means of identifying = nurse and phlebotomist OR barcode reader and phlebotomist
- unique identifier, unique lifetime identifier, PHN, military ID, RCMP ID
- legal first and last name
specimen type for pretransfusion
2 EDTA
what information MUST be on the requisition?
- first and last name
- ULI
- BBIN/TSIN
- time and date
- 2 signatures (nurse and collector or barcode)
- patient ID + labeling MUST occur at bedside*
what info must be on the specimen tube?
first and last name
ULI
BBIN
BBIN
blood bank identification number
TSIN
transfusion service identification number
what must you do if there are any missing inf, illegible, or mismatches (letter/number)?
- reject specimen and request recollection
- fill out occurrence management form (RLS)
when are full clerical checks performed?
- receipt in lab (acceptance/rejection)
- ABO, Rh, Ab screen
- result entry
- constant checks (accession) performed continuously throughout testing
T or F. We check transfusion records on each patient with every collection
T! - ABO Rh type - antibody screen results - antibody identity/Ag typing - adverse events (transfusion rxns) - previous transfusion/pregnancy - special instructions/products > irradiated, washed, IgA deficient
how many ABO Rh tests must be performed to comply with electronic XM?
2
how many ABO Rh tests must be performed to comply with electronic XM?
2
- historical type is OK if performed by testing lab
- ABO Rh is always done on current sample
- any discrepancy must be resolved
- mismatch from historical record must be investigated
> repeat patient ID, collection
what is an anitbody screen?
- detects Abs to clinically significant antibodies
> Rh, Kell, Duffy, Kidd, Ss
minor crossmatch
“minor” crossmatch is designed to test opposite compatibility: The donor’s serum/plasma with the recipient’s red cells. For example, to perform a minor crossmatch between a group A blood donor and a group B recipient, blood bank personnel would mix the donor’s plasma/serum (containing anti-B antibodies) with the recipient’s red blood cells
what happens after crossmatch?
- allocation or tagging
- issuing
- traansfusion
allocation
- unit is tagged with first name, last name, ULI, BBIN
- designated for THAT patient
- 96 hrs
what does issuing mean?
when the allocated unit leaves blood bank
process of transfusion
- two nurses ID patient (vs tag)
- transfusion started within thirty minutes of issue
- unit is transfused within 4 hrs
- vital signs taken before, 15 min in, and after infusion of product
advantages of a type & screen
- prevents allocation of blood that won’t be needed
- permits more stock to be available
- makes good use of time and resources
- decreases cost
- if blood IS required, electronic XM is quick!
advantages of a type & screen
- prevents allocation of blood that won’t be needed
- permits more stock to be available
- makes good use of time and resources
- decreases cost
- if blood IS required, electronic XM is quick!
type and screen
- patent ID, valid sample
- history check
- ABO Rh
- Antibody screen; if no history and antibody screen is neg = STOP
- then when need transfusion = electronic XM
how does the procedure for antiboy screen differ if there is a history of clinically significant Abs or antibody screen is positive
- antibody identification, DAT
- antigen type patient (should be Ag neg)
- antigen type donors (based on Ag frequency)
- serologically crossmatch 2 units
issuing blood in an emergency
- if ABO unknown or unresolved discrepancy = issue group O
- if Rh unknown discrepant =
> issue Rh pos to males > 4 mos and females >45 y/o
> issue Rh neg to males < or = 4 mos nd females < or = 45 y/o - all unmatched blood is k neg in EDM zone *
limitations of pretransfusion testing: antibody screen
may miss Abs to low frequency antigens not represented on screen cells
limitations of pretransfusion testing: IS crossmatch
- false neg due to weak ABO Ab - important to check ABO typing
- false pos due to cold IgM antibody reacting at RT (allo or auto)
limitations of pretransfusion testing: serological XM
- weak Ab and dosage (donor cell heterozygous expression of Ag)
- donor Ag neg for corresponding Ab
- screening cells are more sensitive than donor cells
