108. Blood and Blood Products Flashcards
Blood banking: RBC aims for viability of ?% of cells 24 hours after infusion
75
Blood banking: RBC contain anticoagulant that make half life ? days
vs additives contribute make half life ? days
35 vs 42
Blood banking: RBC changes secondary to storage (4):
- loss deformability
- leak K
- Irreversible membrane changes
- biochem alterations
Blood typing: what is this?
process of categorizing blood by antigens expressed on RBC and antibodies contained in serum
Blood typing: How many blood system types?
> 30
Blood typing: what blood system type main categories do we care about?
- abo
- rh
- Kell, duffy and Kidd
- type and screen/ type and cross match
- titer testing (whole blood donation)
Universal donor blood type for RBC
why?
O -
has no antigen A or B, so has anti A and anti B antibodies in the serum (so not whole blood universal donor!!)
Universal recipient blood type RBC ?
AB+
Rh: what is most immunogenic?
D antigen
+ means present
Rh+ what is needed for a significant reaction
person Rh- and prior exposure so body has. time to build antibodies (ie through pregnancy or blood transfusion)
What does a type and screen get you?
abo grouping
rh type
antibody screen for unexpected non abo or rh antibodies
Type and crossmatch - what has to be done first, and how is this accomplished? what does it get you?
type and screen first
mixes receipient serum with donor rbc to observe for agglutination
antibody screen and abbreviated crossmatch require 45-60 min to watch for this agglutination and if occurs, has to undergo complet crossmatch (can take several days)
Titer testing - whole blood donation - what is this?
O has anti A nad B which can cause destruction of A/B RBC
can mitigate this by giving type specific blood or low titer O universal blood (if titer <256 saline dilutions)
Low titer O blood does not cause hemolysis with up to ? units given
4
RBC volume
300ml
Storage temp RBC
1-6 deg
Prep type RBC in transfusion
10-45 mins
2 ways to get platelets?
Buffy coat from 4 units
apheresis
Vol buffy vs apheresis platelets
350ml vs 330
Vol buffy/ apheresis platelets - storage limit
5d
Vol buffy vs apheresis platelets storage temp
20-24 deg both
Vol buffy vs apheresis platelets - time to prep?
both 5 mins
Frozen vs apheresis plasma: vol?
290 ml vs 500ml
Frozen and apheresis plasma, cryoprecipitate: storage limit?
1 year
Frozen and apheresis plasma, cryo: storage temp?
-18 or colder
Frozen and apheresis plasma, cryo: time to prep?
30mins
Cryoprecipitate: approx vol?
10ml
How are RBC transfusions administered?
filter, IV and IO with NS
3 main preparations for PRBC:
washed
leukocyte reduced
irradiated
RBC preparation: Washed RBC: why done?
remove residual plasma and any remaining leukocytes, plt, microaggregates, plasma PRO and free hemoglobin
to reduce titer of anti a nad anti b antibodies
for recurrent allergic reaction to transfusion or IGA deficiency
RBC preparation: Washed RBC: which pt require this? (3)
recurrent allergic reaction to transfusion or IgA or paroxysmal nocturnal hemoglobinuria
RBC preparation: Washed RBC: how long does this take and what does it do to viability?
1hr
reduced to 24h
RBC preparation: Leukocyte reduced RBC: why is this done?
wbc can cause febrile reactions, immune sn and transmission of disease (viral, bacterial)
RBC preparation: Leukocyte reduced RBC: how is this done and for which 3 gr of pt?
through leukocyte filter, reduces wbc by 99.9%
chemo pt
multiparous females
pt receiving multiple transfusions
RBC preparation: Irradiated RBC: why is this done?
reduces GVHD by destorying donor lymphocytes
RBC preparation: Irradiated RBC: how often does GVHD occur and how high is mortality?
1/1 mill
90% mort
RBC preparation: Irradiated RBC: which 8 populations of patients may benefit from this?
Immunocomp
HLA match to donor
neonatal or IU transfusion
hematologic malignancy
stem cell transplant/harvest
hodgkin lymphoma
directed donation from family
congenital cellular immune deficiency
pt with antithymocyte globulin or chemo with purine analogs (fludarabine ex)
Whole blood: is this as good as components in hemorrhaging pt?
yes and actually lit recommends whole blood when available
What are the benefits of whole blood?
- stored whole blood less dilute than composite parts
- physioologic balance
- smaller vol of anticoagulant/preservative required
- higher levels of hemostatic factors
- fibrinogen delivery higher
- hemolytic transfusion rate is lower as less donor exposures
- Improved time to completion of transfusion
- Errors with transfusion or type sp blood minimized
- Cost effective
Drawbacks of using whole blood
shelf life shorter
concern for low titer O universal whole blood - isoimm causing hemolytic disease of newborn (but consider candidate for rhogam)
What is an autotransfusion?
giving pt back own blood
Advantages of an autotransfusion:
immediately available
blood compatible
elimination donor to pt disease transmission
lower risk circulatory overload
fewer direct complicartions related to transfusion (low ca, high k, hypothermia, metabolic acidosis)
acceptable to religious inds
Disadvantages of autotransfusion
impractical as low number of appropriate trauma pt
requires sp training
time to set up
Which 3 groups of pt need CMV testing on their RBC?
seronegative pt (pregnant)
fetal or IU transfusion
solid organ, stem cell or BM transplant recipients who are CMV negative
What is the goal of an RBC transfusion?
improve o2 delivery to tissue at microvascular level
What is the commonplace transfusion threshold?
70g/L
What specific patients may benefit from a transfusion threshold of 80g/L?
ortho surgery
cardiac surgery
pre-existing CV disease
Clinical judgement is still important when deciding to transfuse - what might you consider as key signs to continue/start transfusion?
ongoing sign inadequate perfusion - elevated lactate, ams, decreased u/o
1 unit of PRBC incr hbg by ?
adult vs ped
10 vs 10ml/kg
how fast should you give most transfusions?
60-90 mins
not more than 4 hours as bacteria can grow
Indications for RBC transfusion:
- active hemolysis with hemoglin <70 (to keep hemoglobin >70)
- consider 80 of unstable or ACS, CAD, uncontrolled/unpredictable bleed - anemia in CC: hemoglobin <70
- chronic anemia - probably consider IV iron or minimal to get no sx of anemia
chelation therapy if pt iron overload, transfusion dependent or life expectancy more than 1 year
How many transfusions do you then typically see iron overload?
2 units
Fresh frozen plasma: what does this have?
all clotting factors
Fresh frozen plasma: vol?
200-250ml
Fresh frozen plasma: must be ? compatible
abo
Indications Fresh frozen plasma:
- INR >/= 1.8: active bleed or prior sign operation *liver disease pt often have preserved thrombin generation despite elevatred INR and often do not need abnormality correction)
- results not availbe for inr/ptt - microvascuular bleed orv massive transfusion and pt cannot wait 30-45 minsc for inr/ptt results
- any - TTP
Fresh frozen plasma: use for warfarin reversal, xa or IIa inhib anticoag reversal or heparin/LMWH reversal?
no!