Blood components and preparation

basic information about preparation of blood products and its uses in clinical practice

1. Blood components and Preparation R.Srihari

2. Topics for discussion Introduction General Principles Blood Collection Anticoagulant/Preservative Solutions Blood Components Storage conditions Blood Replacement products: Recommended uses and effects in adults

3. 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

4. General Principles Components of whole blood Plasma RBCs WBCs Platelets Cryoprecipitate They have requirements for optimum storage and preservation of function

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. } Packed Red Cells } Buffy Coat } Plasma Centrifugation - Principle Blood cells have different Sedimentation Coefficients

16. Protocol for preparation of Red Cells and FFP Whole Blood Soft spin at 4 o C Red cells Plasma freeze at -30 o C FFP Within 8 hours

17. 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?

18. Platelet concentrates: Single donor apheresis platelets: ( cytapheresis )

19. 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?

20. Preparation of Platelets from whole blood Whole blood Soft spin at 22 o C within 8 hrs Red cells Platelet rich plasma (PRP) Hard spin at 22 o C Plasma Platelet Conc.

21. 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

22. 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

23. 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

24. Fresh Frozen Plasma Slow thaw at 4 o C in Cold Room or Hard spin at 4 o C Blood Bank Refrigerator Cryopoor plasma Cryoprecipitate Preparation of Cryoprecipitate

25. WBCs: Contain Granulocytes + 20% plasma Plasma derivatives: Rh immune globulin Albumin Globulin

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