Bloodbanking Quiz 4

Basic mechanism for HDFN

fetal cells are destroyed by maternal IgG antibodies

3 types of HDFN

ABO, Rh, Other IgG

ABO antibody for HDFN

anti-A,B

Rh antibody for HDFN

anti-D

Incidence of ABO vs Rh HDFN

1 in 5 vs 10

Blood type of mother and baby of ABO vs Rh HDFN

O mom, A/B child vs Rg neg mom, pos baby

Severity of disease of ABO vs Rh HDFN

mild vs severe

Laboratory data of ABO HDFN

weak/negative DAT, spherocytes, mild/no anemia

Laboratory Data of Rh HDFN

strong DAT, no spherocytes, moderate/severe anemia

Prevention of ABO vs Rh HDFN

no vs RhIG

Prenatal studies for evaluating HDFN

complete history, ABO/Rh, Ab screen

Significant AB screen results for HDFN

titer of 32, raises by 2 dilutions

Amniocentesis for evaluating HDFN

amniotic fluid is removed for bilirubin analysis

Postnatal studies for evaluating HDFN

tests maternal and cord blood

Tests done on maternal blood in postnatal studies

ABO/Rh, Ab screen then ID

Tests done on cord blood in postnatal studies

forwards ABO/Rh, DAT

Significance of pos DAT and negative maternal AB screen

ABO HDFN

Methods of treatment for HDFN

intrauterine transfusion to correct fetal anemia, early delivery, exchange transfusion for severe cases

Requirements for early delivery to treat HDFN

at least 34 weeks, assess lung maturity

Exchange transfusion procedure

remove some of baby’s blood and transfuse compatible blood

Goals of exchange transfusion

remove ab-coated cells, unbound incompatible abs, baby’s plasma to reduce load of bilirubin, replace incompatible RBCs

Blood used for exchange transfusion

group O packed red cells reconstituted with FFP

Requirements for blood used in exchange transfusion

Sickle cell/CMV negative, prewarmed, <7 days old, irradiated

Rh immune globulin definition

concentrated/purified solution of IgG anti-D from human plasma

RhIG purpose

prevents active immunization to D

Conditions requiring administration of RhIG

postpartum within 72 hours, prenatal at 28-30 weeks

Criteria for RhIG administration

rh neg mom, rh pos baby, no anti-D in mom’s serum, infant DAT negative for D

Massive feto-maternal bleed definition

entry of fetal blood into maternal circulation during pregnancy/delivery

Screening procedure for fetomaternal bleed

rosette test

Rosette test procedure

D pos indicator red cells form rosettes around D pos fetal cells

Definitive procedure for fetomaternal bleed

kleihaur-betke acid elution

Kleihaur-betke acid elution procedure

based on resistance of fetal Hgb to elution in acid media, calculates percent of fetal cells in circulation

Equation for volume of fetal blood (mL)

% of fetal cells x 50

Equation for number of vials of RhIG

ml of fetal blood/30

Four-fold rationale for transfusing blood components

increase oxygen carrying capacity by red cells, restore: coagulation factors w/ plasma, platelet numbers/function by PLT, maintain blood volume

Purpose of separating whole blood into components

appropriate therapy for each patient, optimal storage, maximizes resources

Features of donated blood product

anticoagulant/preservative solution, satellite bag, sterile closed system, 450 mLs

Low volume unit definition

300-400 mLs, only makes pRBCs

Anticoagulant/preservative purpose in blood product

maintain cell function and viability

Rule for blood product administration

FIFO

Purpose of satellite bag

separates products

Purpose of polyvinylchoride/plasticizer in donor unit

allows bag to breathe for blood to have gas exchange

Order of blood separation

whole blood, soft spin, pRBCs, satellite bags, heavy spin, FFP then PLT

Light spin duration

5-8 mins

Heavy spin duration

15 mins

Storage requirements for pRBCs

refrigerate at 1-6C

Storage requirements for plasma

freeze at -18C

Storage requirements for platelets

placed on rotor for agitation at RT

Storage requirements for cryoprecipitate

freeze at -18C

Purpose of soft spin

express of plasma/platelets into satellite bag

Purpose of heavy spin

express of plasma then platelets

Use of pRBCs

increase oxygen carrying capacity

Use of FFP

restore coag factors

Use of platelet concentrate

restore platelet number and function

Use of cryoprecipitate

restore certain coag factors (I, vWF)

Target patients for pRBCs

malignancy, post surgical, renal, sickle cell

Target patients for FFP

post surgical, vitamin K deficiency, burn patients

Target patients for PLT

chemo, massive blood loss, trauma

Target patients for cryoprecipitate

von willebrands patients, massive transfusion, coag disorders

How to prepare cryoprecipitate

thaw FFP, remove plasma, refreeze

Shelf live of FFP and cryoprecipitate

1 year

Shelf life of PLT

5 days

Administration procedure of routine red cells

patient ID verified, 4 hour time limit, filter to remove clots/aggregates

Function of citrate in CPD

bind calcium to prevent coagulation

Functions of phosphate in CPS

O2 binding, determine red cell function, cell metabolism

Functions of dextrose in CPD

glucose for cells, maintain cell metabolism/energy

Shelf life for red cells preserved in CPD

21 days

Function of adenine in CPDA-1

supports ATP synthesis

Shelf life of cells preserved in CPDA-1

35 days

Function of adsol in CPDAS-1

extend shelf life of pRBCs

Shelf life of cells preserved in CPDAS-1

42 days

Changes to pH/acid production in stored blood

decreased

Changes to ATP/active metabolism in stored blood

decreased

Changes to 2, 3-DPG/ability to retain it in stored blood

decreased

Changes to potassium in stored blood

increased

Testing performed on donor blood unit

ABO/Rh (weak D0, ab screen, viral markers

Storage requirements for Frozen RBCs

-65 C

Storage requirements for washed RBCs

1-6C

Storage requirements for Irradiated RBCs

1-6C

Storage requirements for granulocyte pheresis

rt

Shelf life of frozen RBCs

10 years

Shelf life of washed RBCs

24 hours

Shelf life of irradiated RBCs

28 days

Shelf life of granulocyte pheresis

24 hours

Use of washed RBCs

IgA deficient patients

Use of irradiated RBCs

reduce risk of GVHD

Use of granulocyte pheresis

neutropenia, chronic infections, stimulate donor cell production

Platelet administration guidelines

platelet count <20k, for surgery <50k

Incremental increase of Hgb with 1 unit

1 g/dL

Incremental increase of Hct with 1 unit

2-3%