Blood components and

Preparation

R.Srihari

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?

• Platelet concentrates:

– Single donor apheresis platelets: (cytapheresis)

• 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

Thank You