components and prep Flashcards
when is whole blood transfusion used
need both volume and Hgb replacement
whole blood donation standard ratio
14 mL additive solution for every 100 mL of whole blood collected
what is reconstituted blood
group O cells with AB plasma (universally compatible)
24 hrs til expiration
soft spin yields
platelet-rich plasma
cryoprecipitate is rich in what coag components
factor 8
fibrinogen
RBC storage requirements
temp: 1-6
shelf life: 42 days w AS-1
(35 with CDPA-1)
fresh frozen plasma storage requirements
temp: <-18
shelf life: 1 year
“thawed plasma” storage requirements
temp: 1-6
shelf life: 5 days
thawed fresh frozen plasma storage requirements
temp: 1-6
shelf life: 24 hrs (up to 5 days)
platelets storage requirements
temp: 20-24
shelf life: 5 days from collection
frozen cryo storage requirements
temp: <-18
shelf life: 1 year
thawed cryo storage requirements
temp: 20-24
shelf life: 4 hours
packed red cell prepared by
removing as much plasma as possible
AS-1 must be added within 3 days of collection or CDPA
what is used to collect double red cells
apheresis
final RBC product needs hematocrit of
55-65%
how does RBC aliquot work
bag gets zeroed on a scale and requested amount is expressed into aliquot bag
-closed system doesn’t compromise sterility so expiration is unchanged
RBC aliquot syringe
syringe can be used to draw blood out of unit
expiration is changed to 24 hrs because sterility is broken
preparing long term storage RBC by
frozen, glycerolized RBC
stable at -65 for 10 years
when time to use: thawed, washed, deglycerolized cells
when are RBC used for long term storage settings
-rare blood types
-autologous donation
-military use in remote areas
high glycerol
40% weight per volume
-more cryoprotection to the cells so they can be frozen “slowly” in a normal -65 freezer
wash carefully when thawing to avoid contamination
low glycerol
20% weight per volume
-must be rapidly frozen with LN2 and stored in much more expensive -120 degrees freezer
-more sensitive to lysis from overhandling and temperature fluctuations
reduced change of GVHD
irradiated cells
FDA requires every irradiated unit to receive at least 25 Gy to center of the unit and no less than 15 Gy to any single part
new expiration date for irradiation
28 days from time of irradiation OR original outdate
-whichever comes first (only really applies to RBC unit)
for each RBC transfusion what bump should you get in Hgb
1 g/dL per unit
-depends on final Hct of unit and pt size
indication for RBC transfusion
general- anemia
HGB <7.0
active bleed
hemoglobinopathies
platelets must be prepared within
8 hrs of collection if made from whole blood
platelet units are screened for
presence of NSAIDs which damage the platelets
-done by removing platelet-rich plasma and pelleting the platelets with hard spin
platelet units must have
a device to detect bacterial contamination OR
pathogen reduced units
-continuously agitated while stored
random donor platelets from whole blood should have
5.5 x 10^10 platelets
single donor platelets from apheresis should have at least
3.3 x 10^11 platelets
-more concentrated
single donor units can be matched how
HLA
-RDP tend to be pooled to get required amount
-SDP more expensive
indications for platelet transfusions
thrombocytopenia or
less than 50,000 during an active bleed/ pre- or intraoperative
-or trauma setting
how much bump of platelets is received when transfused
10-40,000 plt
-depends on product type, actual plt count of unit and pt size
small increase of plt difficult to see refractoriness
platelet- poor plasma that is frozen within 8 hrs is labeled
FFP
if plasma is frozen within 24 hrs it is labeled as
PF 24
-good for 1 year
plasma can be kept liquid up to
5 days but only good for volume replacement like thawed plasma
thawed FFP has all the stable and labile clotting factors present but
factor V and factor 8 degrade within 24 hours at 2-8 degrees
-PF24 lacks these factors
after 24 hrs the plasma unit is
“thawed plasma”
-anything beside coag needs
convalescent plasma
apheresis plasma collected from a donor that has recovered from particular illness and it will be given as a form of passive immunity
-MERS, SARS,Ebola, Flu, Measles, etc
indications for plasma transfusion
INR>1.5 or PT> 1.5x normal limit
-DIC
-liver failure
-nonspecific coagulopathy
-correct warfarin overdose
-massive trauma
-therapeutic plasmapheresis
plasma retains most of
coag factors for several days
-now we use thawed plasma up to 5 days even to correct coagulopathy
how is cryo prepared
slow-thawing FFP
-the clotting factors (factor 8 and fibrinogen) sediment and can be separated and frozen
units of cryo can be made from pools of
up to 10 donors to get a good dose
-became a big problem during HIV
-doctors prefer to given recombinant coag factors
who is cryo used for
hemophiliac patients when having a bleeding episode
-volume is not needed
indications for use of cryo
fibrinogen < 100 mg/dL
massive trauma
hemophilia in emergency setting when factor 8 not available
what is either purified from FFP or recombinant and pathogen inactivated
factor 8, 9, 7a, protein S and C
-factor 8 includes vWF
what is purified from pooled plasma
IV immunoglobulin
-mainly IgG
RhIg can be used to treat
ITP in D + pts
-D+ RBC’s distract RES from killing platelets until problem gone
what is apheresis
removing a specific component from whole blood and returning the remainder to donor
-Edwin Cohn
therapeutic apheresis
pathological substance removed from circulation
apheresis procedure
single or double phlebotomy
-takes 45-120 min
-may also have co-infusion of saline to prevent hypovolemia
blood from the send tube us immediately mixed with
citrate to anticoag it
after mixing with citrate it enters the system either through
intermittent flow centrifugation (IFC) or continuous flow centrifugation (CFC)
-CFC requires second venipuncture
for erythrocytapheresis must have a way to measure total
RBC loss (not just donation volume ) so don’t exceed max amount of loss
intermittent flow centrifugation
blood drawn in batches or cycles
-citrate mixed with blood as it is pumped into bowl, spun, and desired component pumped into collection bag
-remainder pumped into reinfusion bag and returned to donor
IFC may take how many cycles
6 -8 to remove sufficient component
continuous flow centrifugation
blood is withdrawn, processed, and reinfused in a continuous manner
-requires 2 venipuncture sites OR PICC line with double lumen
-reduces amount of blood processed which needs to stay below 10.5 mL/kg
changes in blood volume can cause reactions in
younger patients
-donor must be monitored for total volume of lost RBC’s
double RBC apheresis freq
once every 112 days
plasma frequent apheresis freq
every 2 days (not more than twice a week)
plasma infrequent apheresis freq
every 4 weeks (not more than 13 times/year)
platelets single unit apheresis freq
every 2 days
(no more twice a week and 24 times a year)
platelets 2x/ 3x apheresis freq
every 7 days
specific testing ordered by doctor for apheresis
CMP, PT/aPTT, CBC
for freq plasma/platelet donors
why not just prepare plasma from whole blood?
donor benefits: fewer rxn
product benefits: larger volume collected
why larger plasma volume better?
-allows collection of specific ABO types
-allows collection of greater amount of specific products
-collection of sufficient product to make cryo, IVIG, hepatits IG
platelets removed by apheresis can replace a unit of
6-8 pooled units harvested from whole blood
for platelet donation donor must have plt count of
150 x 10^9/L
-except for initial donation or if 4 or more weeks have elapsed since last apheresis ???
most platelet units are produced with a
leukocyte filter
granulocyte units can be used to
treat infections that are unresponsive to drugs
(sepsis in neonates)
what is the only efficient way to capture enough granulocytes
apheresis
leukocyte donor will be given
corticosteroids or G-CSF to increase number of circulating cells
-hydroxyethyl starch will be added to removed blood to help sediment RBC (better separation from buffy coat)
RBC exchange
erythrocytapheresis
rather than collecting bone marrow
hematopoietic progenitor cells
