Path Heme/Onc/ Blood Bank Flashcards
What are four steps of pretransfusion testing?
- ID blood and paperwork
- ABOD typing
- Ab screen
- Crossmatch donor RBC and recipient serum
ABO abs are naturally occurring Ig___ and (do/do not) require prior exposure.
IgM
do not
What do IgM abs of ABO do?
fix complement and cause intravascular hemolysis causing an immediate transfusion reaction
Rh/D abs (are/are not) naturally occuring abs and (do/do not) require prior exposure).
are not
do
Rh abs are of Ig___ and cause…
IgG
delayed hemolytic transfusion rxn and hemolytic disease of the newborn
Rh abs may cause (intravascular/extravascular) hemolysis.
they do not fix complement so would only cause extravascular hemolysis
What causes Hemolytic Disease of the Fetus/Newborn?
hemolysis in fetus from Mom’s IgG that crossed the placenta
What are symptoms of HDFN?
anemia hypoxic injury to fetus hydrops fetalis (d/t circulatory failure, severe generalized edema) hyperbilirubinemia as newborn kernicterus
What is kernicterus?
when the BBB is suboptimal due to prematurity or immunocompromization, unconjugated bilirubin that is very lipid soluble is able to enter the brain causing acquired metabolic encephalopathy -> cerebral edema; yellow staining on autopsy
What is the MCC of HDNF?
ABO incompatibility
What is the most severe cause of HDFN?
Rh incompatibility
What does RhIg (Rhogam) treat and when would I give it to someone?
Prevents HDNF by preventing antibody production in the mom
give to Rh- mom at 28 weeks gestation and then again within 72 hours of giving birth
This typing looks at pt serum and reagent cells
Reverse Typing/ Back Type
This typing looks at pt cells and reagent sera
Forward Typing/Front Type
What kind of typing tells me what antigens are on pt cells?
Forward Typing
What king of typing tells me which ABO abs are present in pt serum?
Reverse Typing
What is the universal recipient blood type?
AB +
What is the universal donor blood type?
O -
What test determines if there are any in vivo abs attached to RBCs? What conditions is this test used in?
Direct Antiglobulin (Coomb’s) Test - DAT
HDFN
AI hemolytic anemia
transfusion rxn
What test detects in vitro attachment of Ig or Complement and what is it used for?
Indirect Antiglobulin (Coomb’s) Test - IAT
Ab screening and crossmatching - detect unexpected Abs in pt serum; look for clinically significant Ab (IgG, activated above 37C, and Kell, Kidd, Rh)
What is crossmatching?
confirming ABO typing; may detect other abs; done at room temp unless Ab screen is abnl
What kind of typing is used in emergencies?
uncrossmatched: O+ or O-
takes about 5 min to prep
Who gets O- blood?
females still of childbearing age
You’re about to go into surgery, you really don’t think you will need blood for the pt, but want to have some on hand just in case. What are you going to order?
Type and screen only
You’re about to go into surgery, this dude’s a bleeder and you know you’ll need at least a few transfusions. What are you ordering?
Type and crossmatch
One unit of packed RBC will increase hgb and hct how much?
hgb will go up 1g/dl
hct will increase by 3%
How long can you store packed RBCs?
store up to 42 days at 1-6C
What is an indication for leukocyte depleted RBCs?
to decrease risk of febrile non-hemolytic transfusion reaction
to decrease CMV risk
to decrease HLA autoimmune rxn
Frozen, deglycerolized RBCs are for who? How long can they be stored this way?
rare blood types - Bombay
military
can be stored up to 10 years if at -65C
Who really needs to have washed RBCs? What does this remove from the RBCs?
for IgA deficient pt
removes platelets, plasma, and 90-99% of WBCs
Pts at risk for GVHD get what type of blood transfusion products?
irradiated blood products to prevent WBC replication and engraftment
A single donor of platelets gives the collection via…
apheresis
When a pt does not respond to a platelet transfusion, what adjustment should be made?
HLA matched single donor platelets - one of the few times there is reason for a directed donation
If you are washing blood products, how quickly must they be used after washing?
4 hours
What are two things that are not indications for platelet transfusion? why are these not indicated?
TTP/HUS or HIT
due to increased risk of thrombosis
Platelets don’t have to be crossmatched to be transfused, but it is generally best if they are…
ABOD identical
What is the expected response of a single donor unit or pooled 6-pack of platelets?
increases platelet count by about 30-60k
How long do transfused platelets normally live? What would shorten their lifespan?
normally about 6-7 days
shorter if complicated with sepsis, DIC, alloimmunization, hypersplenism, or immune thrombocytopenia purpura (ITP)
FFP must be frozen how quickly? Is there another kind?
within 8 hours or within 24 hours is considered FP24
FFP and FP24 have all coagulation factors, but FP24 has slightly less of these two factors
Factor V and Factor VIII
How long will it take FFP to thaw prior to transfusion?
about 30 min
What are four indications for FFP?
- PT or PTT is >1.5x normal with risk of bleeding
- bleeding in pt with liver disease
- bleeding due to warfarin OD
- Deficient in any of Factors II, V, X, XI
What are the only products if pt is deficient in Factors II, V, X, XI?
FFP or FP24
What is the cold, insoluble form of plasma remaining after FFO has been thawed?
Cryoprecipitate (Antihemophilic Factor)
Cryoprecipitate contains what percent of Factor VIII and fibrinogen of original plasma?
50%
20-40%
What four things does cryoprecipitate contain?
Factor VIII
fibrinogen
vWF
Factor XIII
What are three indications for use of cryoprecipitate?
hypo or afibrinogenemia
Factor XIII deficiency
burn or trauma pts
What is now used to tx von Willebrand Disease and Hemophilia A?
Factor VIII Concentrate (Antihemophilic Factor - AHF)
What Factor treats Hemophilia B?
Factor IX
What hgb range should you consider transfusing PRBCs? When would a pt be symptomatic?
6-10 consider
<6 is probably a symptomatic pt
>10 rarely needs transfusion
Why would I never add lactated ringers to blood products?
contains calcium and could cause clotting
Why would I never add D5W to blood products?
clumping and hemolysis
What is intravascular hemolysis almost always due to? What transfusion reaction is this associated with?
almost always due to ABO incompatibility (IgM)
found in Acute Hemolytic Transfusion Reaction