Lecture 3 - Blood Components Flashcards
what is the storage temperature of red blood cells?
2-6 degrees
what is the storage time for red blood cells?
28 to 49 days
what is the difference in storage time for irradiated red cells?
14 days post irradiation
what is the storage time for washed red cells?
14 days
in what situation are granulocytes used?
life-threatening soft tissue damage, bacterial infection, prolonged neutropenia after chemotherapy
why must granulocytes always be irradiated?
due to high risk of white cell engraftment and graft vs host disease
why does a granulocyte component contain a lot of platelets?
because they are made from the Buffy coat
what is the storage for granulocytes?
20-24 degrees
what type of component must not be agitated?
granulocytes
what situations are platelets used in?
prevention of bleeding in patients with low count or dysfunction of platelets
how long are platelets stored for?
5-7 days
why do platelets need to be agitated?
ensures constant oxygenation and removal of CO2 which prevents granule release and lysis
in what situations does FFP need to be used?
prevention of bleeding due to clotting factor deficiencies e.g. due to massive haemorrhage or liver disease
why can’t FFP be used as a volume expander?
due to risk of allergic reaction
what is cryoprecipitate?
made by thawing fresh frozen plasma at 4 degrees
what is cryoprecipitate rich in?
cryoglobulins, rich in fibrinogen, factor VIII and VWf
what is recommended dose of cryo?
two pools of five units which raises fibrinogen by 1g/L
what is cryoprecipitate used for?
hypofibrinogenemia or acquired dysfibrinogenaemia
what is DIC?
disseminated intravascular coagulation which is blood clotting through the body
what is the maximum storage of FFP and cryoprecipitate?
36 months
how long can cryoprecipitate be stored after thawing?
24 hours
how long should FFP be used after leaving storage?
4 hours
if whole blood was to be used, what would it be used for?
rapid transfusion of plasma and platelets as well as cells
what is the difference between blood components and blood products?
components are made from whole blood donation yet products are made from the plasma component
what are plasma derivatives?
licensed medicinal products made from plasma donations
how are plasma derivatives further processed to avoid infection?
undergo pathogen inactivation steps
what is solvent detergent FFP?
prepared from pools of large donations, the solvent detergent step inactivates bacteria and encapsulated viruses
what is octoplas?
the licenced medicinal product of solvent detergent FFP
what is octoplas LG?
a prion reduced version of octoplas
what is an advantage of the pooling process?
gives a more standardised concentration of clotting factors, lowers risk of allergic reaction
where is solvent detergent FFP used?
in those who have clotting factor deficiency
what is human albumin solutions?
a solution containing proteins derived from plasma yet no clotting factors or blood group antibodies
what is 4.5%/5% HAS used for?
subacute plasma volume loss caused by burns, pancreatitis or trauma and as a replacement in plasma exchange
what is 20% HAS used for?
hypoalbuminaemic patients with liver cirrhosis or nephrotic syndrome
what factors does clotting factor concentrates are not covered?
factor V and factor II
what is riastap?
fibrinogen factor I concentrate and treats congenital hypofibrinogenaemia
in what situations are clotting factors more effective?
in situations of acquired hypofibrinogenaemia
what is octaplex?
prothrombin complex concentrate
what factors does octaplex contain?
factor II, VII, IX and X
what is octaplex extremely useful for?
rapid reversal of warfarin overdose
in what way are red cells damaged by being in storage?
the sodium potassium pump in the red cell membrane is immobilised casing a decrease in intracellular potassium and an increase in cytoplasmic sodium levels
how is acidosis caused as a result of storage?
due to decline of glucose levels due to immobilisation of NA/K pump and low pH levels occur as a result
what causes morphological changes of the red blood cells?
lipid per oxidation and oxidative stress causes formation of sphereochinocytes and osmotic fragility
how does irradiation cause shorter shelf life?
gamma radiation exacerbates storage lesions
what issues can transfusing newborns with stored blood cause?
the stored blood has increased levels of potassium and so has been associated with myocardial hyperkalaemia and neonatal arrhythmia
how can heart complications in newborns be reduced?
transfuse with blood less than 5 days old
what are blood bags manufactured with to prevent coagulation?
citrate phosphate dextrose
what does citrate do in a blood bag?
is the coagulant, removed calcium ions prevents the clotting cascade
what does phosphate do in a blood bag?
counteracts the loss of phosphate lost during storage and improve viability
what does dextrose do in a blood bag?
prevents loss of ATP
what is saline adenine glucose?
an additive that is added to the red blood cells to combat effects of storage
what does saline do as an additive?
maintaining volume and prevents uptake of glucose that occurs when cells packed together
what does adenine do as an additive?
restoration of cell shape, ATP concentration and viability
what does glucose do as an additive?
prevent loss of ATP and enable longer storage
what does mannitol do?
protects the red blood cell membrane and reduces haemolytic by acting as a free radical scavenger
why might blood be leucodepleted?
transfused leucocytes induce immunosuppressive changes so leucodepletion reduces the incidence of transfusion reactions
what is the negative effects of leucodepletion?
may induce the incidence of postoperative infection and recurrence of cancer
how is leucodepletion carried out?
filtration of multiple layers of synthetic polyester non-woven fibres that selectively retain white cells
how can leukocytes cause infection in the host?
in immunosuppressed patients, white cells can engraft and detect the host as foreign, aka graft vs host disease
what type of patients should receive phenotyped blood?
women of childbearing age, those with alloantibodies, need to be Kell and Rhd negative
what patients are seen as transfusion dependant?
those with sickle cell anaemia or beta thalassaemia
what is the Coombs test?
use a sample of patient serum against donor red cells which form complexes, anti-human Ig’s are added which join to the recipients Ig’s and therefore join the red cells together causing agglutination
what is the advantages of electronic issue?
quicker, avoid potential delays, reduce waste, virtually limitless supply
what are the disadvantages of electronic issue?
must have a reliable and validated lab, cannot perform electronic issue if no IT, some rare antibodies are not detected
