Pretransfusion Testing and Automation in Bloodbank

where does pt identification start

at admission when the armband is generated

how many unqiue identifiers are required for a positive patient identification

two

preferred specimen in blood bank testing

EDTA plasma

how mnay days is a sample good for pretransfusion testing

3 days (expires at midnight)

how mnay days is a sample retained for, incase post transfusion testing is needed

7 days

what temperature are samples stored in

2-8C

what information do we look for in patient history

medical history

transfusion history and reaction

pregnancy history

medication history

what products do not require compatible testing

whole blood (must be identical to patient)

RBCs (must be compatible with recipients plasma)

granulocytes aka WBCs (must be compatible with recipients plasma)

plasma (compatible with recipient’s red cells)

platelets (compatible with recipients red cells)

cryoprecipitate antihemophilic factor (all ABO groups acceptable)

what type of plasma can be given in an emergency conditions

uncrossmatched O negative

red cell transfusion selection for ABO

O^-: O^-

O⁺: O⁺ and O^-

A^-: O^- and A^-

A⁺: O⁺, O^-, A^-, and A⁺

B^-: O^- and B^-

B⁺: O⁺, O^-, B^-, and B⁺

AB^-: O^-, A^-, B^-, and AB^-

AB⁺: O^-, O⁺, A^-, A⁺, B^-, B⁺, AB^-, and AB⁺

plasma transfusion selection for ABO

O: O, A, B, and AB

A: A and AB

B: B and AB

AB: AB

selection of order for unites in blood cell transfusion

O: 1st choice is only O

A: 1st choice is A then O

B: 1st choice is B then O

AB: 1st choice is AB, then A, then B, and then O

what does hold mean

no tests preformed

what does type mean

ABO/Rh

what does type and screen (T&S) mean

ABO/Rh and Absc

what does type and cross (T&C) mean

ABO/Rh, Absc, and crossmatch unnitsv

what does typ and cross (T&C) keep ahead mean

ABO/Rh, Absc, crossmatch units

keep ahead means lets say they ask for two units, when you use one you’ll get another

what does a crossmatch entail

patient plasma + cell suspension from donor units (like from a pigtail) read at IS

no agglutination means units are compatible

if a clinically significant antibody has been detected at the antiglobulin stage what is required

crossmatching

when sleecting units for transfusion does the ABO need to be compatible/identical

it needs to be type-specific

what type of blood needs to be chosen for recipients who are D negative at IS

Rh negative

if a person has unexpected antibodies what type of blood should they be given

antigen negative blood

what causes incompatible pretransfusion test results

negative antibody screen and incompatible crossmatch at IS

positive antibody screen and incompatible at antiglobulin (AHG) crossmatch

reasons for a negative antibody screen and incompatible crossmatch at IS

incorrect ABO grouping of recipient or donor unit selected

cold reactive allo- or autoantibody in plasma

abnormalities in recipients plasma (rouleaux, DARA)

possible reasons for positive antibody screen and incompatible at antiglobulin (AHG) crossmatch

donor RBCs have a possible DAT

antibody is only reactive with RBCs having strong expression of particular antigen (dosage) or variation in antigen strength

antibody is low frequency

limitations of pretransfusion testing

hemolytic transfusion reaction if pts antibody was too weak to be detected

hemolytic transfusion reaction due to pt misidentification

transfusion-associated graft vs host disease and transfusion related acute lung injury

hemolytic reaction due to recieving hemolyzed RBCs

allergic, febrile, and bacteriogenic reactions

disease transmission

2 final identification requirements for issuing blood

two-person verification system

automated ID technology (barcoding)

how long can the units of blood be away from the lab if it’s needs to be returned to circulating inventory

30 minutes

how long do you have to complete a blood transfusion

four hours

definition of massive transfusion

the administration of 8-10 units of blood in an adult recipient in <24 hours or acute adminsitration of 4-5 units within 1 hour

what is the ratio of product transfusion according to the ACS (american college of surgeons)

1:1:1

what type of donor units are selected for intrauterine transfusions

group O, Rh negative RBC units that are fresh (< 7 days old), leukocyte-reduced, irradiated, negative for sickling hgb, and antigen negative

what is used to trap red cells in gel technology

dextran acrylamide gell particles

pricniple of gel technology

ultilizes a microtube attached to a card that containd an upper reaction chamber and long, narrow portion

the column contains gel particles which combine with reagents

centrifugation of RBCs occurs through the gel and measured volumes of red cells and plasma/serum are added to allow red cell sensitization to occur

centrifuged again to allow contacts with antisera and gel

reaction of tube A

4+

reaction of tube B

3+

reaction of tube C

2+

reaction of tube D

1+

reaction of tube E

0

advantages of gel technology

standardization

stable, well-defined endpoints

simple procedures (very fast)

objective, reproduceable, and consistant

decreased sample volume needed (don’t need full blood tube to preform)

enhanced sensitivity and specificity (picks up a lot of insignificant stuff though)

disadvantages of gel technology

sample restrictions

special equiptment needed

calibrated pipette must be used

immucor principle of solid technology test

test plasma and LISS added to microwells already coated with antigen

incubate microplate so antibodies can bind to antigen

wash with buffered saline

add IgG-coated indicator cells and centrifuge to force the indicator RBCs into close contact with antibodies

how does the use of LISS affect agglutination

if ab-ag complex occurs, it adheres to the walls of the test well

what color does the solid technology indicator change to

purple to blue

circle one grade

4+

circle 2 grade

3+

circle 3 grade

2+

circle 4 grade

1+

circle five grade

0

advanatges of solid phase

standardized

stable, well defined endpoints

no predilution of reagents

can test hemolyzed, lipemic, and icteric samples

enhanced sensitivity

long shelf life of microplates (120 days)

disadvanatges of solid phase

need specialized equiptment

technique can affect the results of a manual test

may detect weak autoantibodies