exam 2 - compatibility testing Flashcards
which of the ff is NOT part of the purpose of compatibility testing?
a. Verify the blood product is ABO compatible
b. to select blood products will have acceptable survival
c. ensure that no clinically significant destruction of the transfused
d. detect unexpected Ab RBCs
D
this for ab screening
(T/F) compatibility testing will detect Abs in the recipient’s plasma that are reactive by the crossmatch procedure
true
_____ the most common type of error encountered in transfusion
Misidentification of the recipient of blood (WBIT)
this is a clerical error
which of the ff are not checked in the pretransfusion process?
a. positive ID of recepient
b. previous transfusion records
c. ABO and Rh typing of recepient
d. confirmation of ABO and Rh typing of donor
all are needed!
_____ the ideal age that the sample can be kept/ stored before testing for crossmatch
2 weeks
~3 days if pregnant or recently transfused
(T/F) crossmatch testing should include AHG test for patients with history of clin. sig and atypical ab
true
AHG not done if NO clin sig ab detected and NO history of atypical ab
_____ are the things that must be demonstrated/ detected in compatibility/crossmatch testing (4)
demonstrate
1) ABO incompatibility and
2) clinically significant Abs, include the
3) Antiglobulin test (if pos for current or history of clin sig ab) and
4) Detects errors in labeling, recording, and identification
____ a type of crossmatching that is done when a patient has below threshold levels of detectable or currently reactive atypical allo-ab
antiglobulin xmatch
(T/F) in the pretransfusion process, the sample must be typed (and checked) twice by two different techs
true
(T/F) in pretransfusion process, both Rh pos and neg results must be confirmed
false
Rh neg only is confirmed
(T/F) the donor blood product must be both ABO compatible, meaning it must be the same ABO type
false
not necessarily same as long as compatible
(T/F) antigen negative units must be given to recipients with significant antibodies even if the ab is not detected anymore
true
____ a type of compatibility testing done if patient has no history for atypical ab or not pregnant
immediate spin crossmatch
____ a type of compatibility testing done if record shows two separate blood types on patient (? clarify)
electronic/ computer xmatch
which of the ff is not a reason for a negative an screen and incompatible AHG crossmatch?
a. Donor RBCs are DAT positive
b. Donor unit has a low incidence antigen
c. Antibody shows dosage effect (screen cells are single dose)
d. Rouleaux
none
which of the ff crossmatching procedures do not apply to neonates?
a. ABO and Rh typing of RBCs
b. ab detection in infant or mother’s serum and xmatch
c. IS crossmatching when no alloantibodies are detected
d. Repeat testing during same stay period
D
repeat testing not required
which of the ff is false?
a. plasma is preferable to use in pre transfusion testing
b. blood samples should not be taken from intravenous (IV) tubing lines
c. recent pregnancy or transfusion indicates an opportunity for a humoral immune response
d. samples fewer than 72 hours after collection must be used for antibody screening and crossmatch testing
A
plasma may have clots forming or inactivate complement = cant detect ab
which of the ff about donor/patient samples is false?
a. Repeat weak-D testing is not required
b. If the Rh type of the recipient cannot be determined and transfusion is essential, Rh-negative blood should be given
c. When an unexpected antibody is found in the patient’s
serum during a screening test, donor units selected
specifically are crossmatched with the patient’s serum
d. the more frequently a patient is exposed to foreign RBC antigens, the more likely that patient will produce unexpected alloantibodies
donor units are selected at RANDOM
(T/F) If a clinically significant antibody is identified, the serologically compatible units are phenotyped with commercial antiserum to verify that they are antigen-positive for the corresponding antibody.
false
need to verify is donor is NEGATIVE for the antigen
which of the ff is false?
a. the first choice for transfusion is blood
and blood components of the patient’s own ABO and Rh group
b. When a recipient must be given blood of
a different ABO group, whole donor blood may be given
c. units selected must lack any antigen against which the recipient has a clinically significant antibody
d. if the Rh-negative unit is near expiration, the unit should be given anyway
C
only packed RBCs are given.
because incompatible preformed ABO ab are present in the whole blood plasma = will attack recipient RBCs
(T/F) in an Immediate spin crossmatch, the absence of hemolysis or agglutination indicates compatibility
true
(T/F ) When no clinically significant unexpected antibodies are detected and there are no previous records of such antibodies, IS crossmatching can be done to test for ABO incompatibility
true
(T/F) ABO incompatibility detection is sufficient if no historical record exists of the detection of clinically significant unexpected antibodies
true
which of the ff is false about incompatibility testing?
a. if hemolysis is present, it must be interpreted as a positive result
b. a reason for positive result is when patient alloantibody is reacting with donor RBCs
c. positive DAT on donor will give negative incompatibility results
d. patient autoantibody will give pos incompatibility result
C
donor’s pos DAT is incompatible with any recipient bcoz the cells are already coated with immunoglobulin and/or complement
