Problem Resolution Dept Exam Flashcards
calculate number of units to test
2/(frequency in decimal form)
ex) 2 units of blood with 34% frequency of Ag:
2/0.34 = 5.9 = six units
select control cells for Ag typing
positive: heterozygous positive
negative: negative
When can you do a selected cell panel?
historical Ab
only 1 positive necessary to confirm
select cells in order to r/o other Abs
prewarm technique use
only for XM
careful not to prewarm a new IgM away
what is extended RT incubation, or 4°incubation, used for?
weak reverse type
requires controls
auto-adsorption cannot be used when…
tx in the last 3 months
instead, use allogeneic adsorption
instances when allogeneic adsorption is used
- short sample
- tx in last 3 months
phenotyping must be done on a —– sample
pre-tx
example of an enzyme tx
DTT for darzalex
destroys K
acidification of serum
increases anti-M activity
which antigens are neutralized using blood group substances?
P1
Lewis
urine Sda
AHG XM used for…
current OR clinically significant Ab (even historical) from ABS/Hx
3 reasons for DAT+
- HDFN
- transfusion rxn
- autoAb
how to perform weak D if DAT+
EGA treat cells
last wash testing purpose
control; tells us that we washed enough, and the Ab detected in the eluate was coating the RBCs, not present in plasma
3 causes of IS problems
- IgM alloAb
- cold autoAb
- rouleaux
2 causes of AHG problems
- IgG or C’ binding alloAb (low-freq)
- warm autoAb
how to release blood when a patient has a warm autoAb
use adsorbed plasma
neat plasma will be incompatible
requires emergency release by Dr
how do you determine which tests to run after trxn?
investigate what is different between the “pre” sample and the “post” sample
acute hemolytic trxn
- red cell incompatibility
- chills, fever, hemoglobinuria, hypotension, renal failure, oliguria, DIC, back pain, pain along infusion site, anxiety
febrile nonhemolytic trxn
- Ab to donors’ WBCs or cytokines in a plt bag
- fever, chills, h/a, vomiting
- avoid with leukocyte reduction
urticarial trxn
- Ab to to donor’s IgE
- urticaria, flushing, angioedema
anaphylactic trxn
- Ab to donor’s IgA, haptoglobin or C4
- hypotension, urticaria, respiratory distress, angioedema, abd pain, anxiety
- avoid by washing product or using IgA deficient plasma
TRALI
- transfusion-related acute lung injury
- donor’s Ab to WBCs (from plasma products); HLA related; no female plasma used
- bilateral pulmonary edema, hypoxemia, resp failure, hypotension, fever
delayed hemolytic trxn
- anamnestic response to RBC Ag
- fever, decreasing Hgb, new positive ABS, jaundice, DAT+/=