Transfusions Flashcards
What are the ABO groups and how do they get placed on RBC surface?
they are carbohydrates
placed on outer-membrane facing proteins through glycosylation
what does plasma normally contain?
antibodies
what is the universal plasma donor?
AB blood since the plasma has no antibodies in it
what is the universal plasma receptor?
O blood since antibodies will not interact with it
What is a common example of blood protein group?
Rh
3 functions of glycosylation
1) antigen recognition
2) protein modification
3) protein anchoring
How long do ABO antibodies take to develop?
about 1-3 months
IgM vs. IgG antibodies
IgM is produced by A or B patients
IgG is produced by O patients
what is the most common blood type?
O
What percentage of the population is positive for Rh?
85%
What response is triggered in an Rh- patient that recieves Rh+ blood?
IgG antibody production
How can a baby be Rh+ and a mother be Rh-?
if baby receives only one Rh copy from father, the baby will be Rh+
Rh- is haploinsufficent
What do you do if a baby is Rh+ and mother is Rh-?
start RhoGAM
prevent mother from ever producing Rh+ antibodies
How do Rh differences between mother/fetus cause hydrops fetalis?
if mother is Rh- she will produce antibodies against the Rh+ fetus
during her SUBSEQUENT pregnancies, an immune response will attack the fetus’s RBCs that are Rh+
this will lead to anemia in the baby and hydrops fetalis
How do you blood type for ABO/Rh compatibility?
type and cross!
forward typing and equivalent test
patient’s RBCs are tested against commercial antibody
RBCs will clot with different antibodies depending what antigen they express
direct coombs
reverse typing and equivalent test
patient’s serum is tested again commercial RBC
serum contains antibodies that may clot with RBC
indirect coombs
antibody screen
test patient serum against RBC with known protein expression (all other proteins besides the patient’s ABO type)
final test to match patient with unit of blood
patient’s plasma is mixed with a sample of donor RBC
did the patient’s plasma attach the RBC?
3 indications for RBC transfusion
acute blood loss >15% TBV
Hb <7
chronic transfusions (thalassemia, sickle cell)
indication for platelet transfusion
quantitative OR qualitative platelet defects and bleeding
Plts < 10,000 with bleeding
Plts < 50,000 for major surgery
indications for plasma transfusion
multiple coagulation factor deficiencies (liver failure, DIC)
rapid reversal of warfarin (vitamin K will take too long)
Dilutional coagulopathy from massive
transfusion
indicates for cryoprecipitate transfusion
Dysfibrinogenemia or
hypofibrinogenemia
complex coagulation factor deficiency
deficiency of specific factors
examples of coagulation factor deficiency
DIC, liver failure
side effect of bacterial contamination of a blood unit
can lead to fatal sepsis?
acute hemolytic transfusion reaction
occurs due to incorrect blood type transfusion
mismatched blood triggers IgG antibody response
preformed antibodies immediately bind
can trigger coagulation and complement
DIC and massive hemolysis
DIC stands for
Disseminated intravascular coagulation
activation and dysregulation of both thrombosis and fibrinolysis
delayed transfusion reaction
rapid hemoglobin decrease over 3-14 days after transfusion
prior exposure to an RBC protein antigen made antibodies in the past
now these antibodies will kick up in transfusion with a larger response
examples of some RBC protein antigens
Kelly, Duffy, Rh
TRALI
transfusion associated acute lung injury
TACO
transfusion associated cardiac overload
transfusion infections
can occur if blood contains a bloodborne pathogen such as HIV or HBV
