Blood components and preparation
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Transcript of Blood components and preparation
Topics for discussion
• Introduction
• General Principles
• Blood Collection
• Anticoagulant/Preservative Solutions
• Blood Components
• Storage conditions
• Blood Replacement products: Recommended uses and effects in adults
Introduction
• Blood components are those derived from
whole blood collected from normal donors by
phlebotomy –using the technique of
differential centrifugation
• These products are prepared in blood centres
or hospital labs
General Principles
• Components of whole blood
– Plasma
– RBCs
– WBCs
– Platelets
– Cryoprecipitate
• They have requirements for optimum storage and preservation of function
• Examples:
– Platelets left in units of red cells at refrigerator
temperatures clump and interact with red cells and
plasma proteins losing their hemostasis capacity
– Coagulation factors, especially factors V and VIII
are labile even at 4 C
• Thus to get maximum benefit from a unit of donated whole blood- plasma, red cells and platelets must be seperated from each other and stored under different temperatures and conditions
• Good manufacturing practices, with which manufacturers of blood components must comply, involve careful monitoring of these conditions and strict adherence to specified quality control measures
• Blood Donors:
– Proper manufacture of blood components begins
with careful recruitment and selection of blood
donors
• 98% - allogenic donors – volunteers
• 1% -autologous donors
• Small amount of blood comes from patients who come
for periodic phlebotomy
• 0.4%- directed donors
• Blood collection:
– At donation site , whole blood is collected from
ANTECUBITAL vein after the site has been
cleansed and sanitised with iodine-alcohol
chlorhexidine based solutions
– A clean uncomplicated venipuncture is necessary
for good flow so as to avoid platelet clumping or
fibrin activation
• 500 ml is collected in most centres
• It is collected into a plastic bag containing anticoagulant-preservative solution and should be gently and regularly mixed with the solution as the bag fills
• Thus a single whole blood donation can provide 1 unit each of red cells, platelets, cryoprecipitate and Frozen plasma for transfusion or for further manufacture into plasma derivatives
• Most blood is collected into
– double bags (red cells + plasma)
– Triple bags ( red cells +plasma + platelets)
– Quadruple bags (red cells + plasma +platelets
+plasma factors)
• Whole blood is never used UNMODIFIED
Anticoagulant/ Preservative Solutions
• Variety of preservative and anticoagulant solutions are available – all based on the use of sodium citrate as anticoagulant
• Till ’80s , the anticoagulant and preservatives were in a single solution such as ACD or CPD
• Most of the whole blood collected now is anticoagulated in the initial bag and then modified
• As soon as possible but before 72 hours of donation, red cells are centrifuged and an integrally attached solution of SALINE + GLUCOSE + ADENINE + MANNITOL(sometimes) is added to the red cells
• This additive solution results in better viability and biochemical function of red cells than is achieved with storage in an anticoagulated solution alone
• Presence of adenine preserves ATP levels providing for less red cell membrane breakdown and longer red cell surivival
• Platelets, if to be transfused, must be removed and processed within 8 hours of collection
• If plasma is frozen within 8 hours FFP
• If plasma frozen within 24 hours after phlebotomy Plasma frozen within 24 hours (PF24)
• Otherwise the plasma is removed within the 72 hour time period and sent for fractionation into gamma globulin and albumin
• Plasma used for fractionation of coagulation factors must be of same quality of FFP or atleast PF24
Blood Components
Cellular components
• Red cell concentrate
• Leucocytes-reduced red cells
• Platelet concentrates
• Leucocytes-reduced platelet
concentrates
• Platelet Apheresis
• Granulocytes, Apheresis
Plasma Components
• Fresh frozen plasma
• Single donor plasma
• Cryoprecipitate
• Cryo-poor plasma
Plasma derivatives
• Albumin 5% & 25%
• Plasma protein fractions
• Factor viii concentrate
• Immunoglobulin
• Fibrinogen
• Other coagulation factors
} Packed Red Cells
} Buffy Coat
} Plasma
Centrifugation - PrincipleBlood cells have different Sedimentation Coefficients
Protocol for preparation of Red Cells and FFP
Whole Blood
Soft spin at 4oC
Red cells Plasma
freeze at -30oC
FFP
Within 8 hours
• Red cell concentrates:
– In many centres , upto 100 percent of red cells are
subjected to filtration to reduce leukocytes prior to
storage –(LR) to reduce transfusion reactions
Washed RBCs?
• The amount of platelets from single donor apheresis platelets contain a minimum of 30000/microlitre in a volume of about 300 ml
• Equivalent to 4-6 whole blood-derived concentrates from whole blood donations
• Clinical trials : apheretic platelets vs Platelets derived from whole blood?
Preparation of Platelets from whole blood
Whole blood
Soft spin at 22oC within 8 hrs
Red cells Platelet rich plasma (PRP)
Hard spin at 22oC
Plasma Platelet Conc.
• Platelets derived from whole blood:– Approx. 20% platelet transfusion doses are provided by platelet
concentrates prepared from individual whole blood units within 8 hours of collection
– These whole blood derived platelet concentrates are administered in groups of 4-8, sometimes pooled in a single pack prior to transfusion
– Can be LR by use of filters designed esp for platelets
– Following Production of PRPs they are subjected to hard spin following which they separate into plasma and platelet concentrate
– Most platelet concentrates contain – 7000 /micro litre in volume of 50 ml
• Plasma :
– FFP and PF24 refer to plasma that is separated and frozen at -18 C within 8 hrs/ 24 hrs of collection of whole blood and can be stored for 1 year
– Documented deficiencies of Factors V VII XI XIII can be corrected by FFP/ PF24 though concentrates for Factors XI and XIII are available
– Thawed plasma, which is FFP and PF24 thawed and then stored at 1-6 C for 5 days is used routinely
• Cryoprecipitate:– Is a mixture of proteins that do not go back in to solution when
frozen plasma is thawed at 4 C
– If a unit of FFP is allowed to thaw for 24 hours, a milky white flocculum consisting of several cold insoluble globulins can be separated from liquid plasma
– Contain Fibrinogen (I), Factor VIII, Factor XIII and Von Willebrand factor
– Volume -10-15ml
– Refrozen to – 18 C : can be used upto a year
Fresh Frozen Plasma
Slow thaw at 4oC
in Cold Room or Hard spin at 4oC
Blood Bank Refrigerator
Cryopoor plasma Cryoprecipitate
Preparation of Cryoprecipitate
• WBCs:
– Contain Granulocytes + 20% plasma
• Plasma derivatives:
– Rh immune globulin
– Albumin
– Globulin