Presentation on theme: "Date: 10/10/14 Blood products By Dr Sarah Rehman."— Presentation transcript:
Date: 10/10/14 Blood products By Dr Sarah Rehman
Blood products ✤ Packed red blood cells (PRBC) ✤ Platelets ✤ Fresh frozen plasma (FFP) ✤ Cryoprecipitate ✤ Human albumin solution (HAS) ✤ Immunoglobulins ✤ Coagulation factors
Donation ✤ Donors have their current health assessed by the Donor Health Check (DHC) ✤ ml of whole blood up to three times a year ✤ Haematocrit or haemoglobin level ✤ To ensure recipient safety the donor is also screened for health risks that might make the donation unsafe. Donors are examined for risk and signs of transmissible diseases such as: 1.HIV, 2.Malaria, 3.Viral hepatitis 4.Variant Creutzfeldt-Jacob Disease (vCJD)
Testing ✤ The blood that is collected is identified for blood type (ABO and Rh), but is also tested to minimise the risk of transmissible infections. The World Health Organisation recommends four core tests as a minimum: -Hepatitis B Surface Antigen -Antibody to Hepatitis C -Antibody to HIV, usually subtypes 1 and 2 -Serology for Syphylis ✤ For patients with specific risks from transfusion, the blood may undergo further processing: ✤ Leukoreduction is the removal of white blood cells by filtration, after which the blood product is less likely to cause alloimmunization, febrile reactions, CMV infections, and platelet refractoriness. ✤ Irradiation, helps to inactivate pathogens (viruses, bacteria and parasites), as well as inactivating white blood cells to prevent graft-versus-host disease
Treated ✤ All blood components used in the UK and Ireland since October 1999 have been leucodepleted ✤ Microaggregate-free blood is used to prevent reactions to leucocyte and platelet antigens ✤ Washed red cells usually have haematocrits of 70-80% and a volume of about 180ml. ✤ Saline washing removes residual plasma (98%), and reduces the concentration of leucocytes, platelets and cellular debris. ✤ Can only be stored for 24 hr at 1-6 ̊ C.
Leukodepleted and irradiated ✤ Irradiated red cells Gamma radiation is used to destroy the lymphocytes Prevent transfusion related graft versus host disease ✤ Leucocyte depleted red cells Leucocyte depleted red cells have had 99.9% of the white cells removed Reduces risk of cytomegalovirus (CMV), Epstein-Barr and febrile reactions.
Storage ✤ The most commonly used solution in the UK is SAGM, which contains sodium chloride, adenine, glucose and mannitol. ✤ Short-term storage of blood relies on a combination of refrigeration and the addition of preservatives. Standard temperature used is 1°- 6°C Acid-citrate- dextrose (ACD), citrate-phosphate-dextrose (CPD) or citrate-phosphate-double dextrose (CP2D), the storage is limited to 21 days Citrate-phosphate-dextrose-adenine (CPDA1) this can be extended to 35 days. ✤ Red blood cells can be stored for much longer periods, even up to 10 years, by freezing (cryopreservation) The units are then placed in special sterile containers and frozen to below -60°C
Issues with storage ✤ Granulocytes Become non-functional after 24 hours of storage Some lymphocytes may remain viable for several weeks Platelet function declines to zero after only 48 hours of storage ✤ Oxygen affinity: Stored blood has depleted levels of 2,3 Diphosphoglycerate (DPG) ✤ Coagulation: Stored blood contains an anticoagulant The labile coagulation factors V and VIII have a 50% decline in activity within the first 72 hours
continued….. ✤ Temperature: The optimum storage temperature of 2°- 6°C is well below normal body temperature ✤ Electrolytes: Constant leak of potassium out of cells and levels can exceed 30mmol/l ✤ Calcium: Each unit of blood contains approximately 3g citrate, which binds ionized calcium ✤ Acid/Base: During storage there is a gradual accumulation of lactic acid which can result in an acid load of mmol/l and a resultant fall in pH
RBC ✤ Whole blood is rarely used, the collected blood is therefore fractionated into its respective components ✤ Packed Red cells: A bag of RBCs have a haematocrit of between 60-70% ✤ The main indications for transfusion is the correction of anaemia or replacement in acute haemorrhage, ✤ A single unit of red blood cells will typically increase the Hb by 1g/dl.
Granulocytes ✤ Indicated for life-threatening infections in neutropenic cancer patients ✤ Collected by apheresis (filtration), and can only be stored for 24 hours at degree centigrade ✤ Require cross match due to presence of RBC ✤ Irradiated
Platelets ✤ Circulatory life span of 8-14 days ✤ Platelets for transfusion are collected in two ways: 1. Pooled platelets 2. Apheresis platelets (equivalent of 4-6 units of random donor platelets) ✤ Platelets last for 3-5 days if stored at 22 ̊ C and at a pH of between 6.2 and 7.8 ✤ Each bag has a volume of ml ✤ Platelet count in pack: > 2.4x1011 per adult dose ✤ The risk of transmission of bacterial infection is higher with platelet transfusions than red cells
Fresh frozen plasma ✤ It contains all the coagulation factors, albumin and a source of plasma cholinesterase ✤ It is frozen within 8 hours and may be stored for up to 1 year at -30 ̊ C. Under these conditions, the loss of Factors V and VIII is kept to a minimum ✤ The frozen plasma can be thawed using a dry oven (10 minutes), microwave (2-3 minutes) or a water bath (20 minutes) ✤ Thawed FFP is best used immediately but may be stored at 4 ̊ C and infused within 24 hours, provided it is kept at this temperature or returned to the blood bank for storage within 30 minutes of being removed from a 4 ̊ C fridge or transport box. ✤ 4-5 platelet concentrates, 1 unit single-donor apheresis platelets, or 1 unit fresh whole blood provide a quantity of coagulation factors similar to that contained in 1 unit FFP ✤ The dose is ml.kg-1 (equivalent to three to four 300-ml packs of FFP)
Cryoprecipitate ✤ Precipitatable cryoproteins are rich in Factor VIII, von Willibrand Factor (VWF), factor XIII, fibronectin and fibrinogen ✤ This is the cryoglobulin fraction of plasma obtained by thawing a single donation of FFP at 4°C ✤ Contain mg fibrinogen and 70 iu factor VIII ✤ 10 prepared units of cryoprecipitate (300 ml volumes) ✤ 1 unit of whole blood provides about 15ml of cryoprecipitate
HAS ✤ Available as 4.5% and 20% (salt poor albumin) solution ✤ Contain mmol/L sodium, latter contains less sodium per gram of albumin ✤ Albumin is heat-treated to kill viruses ✤ It has a shelf life of 2 years and stored at room temperature
Immunoglobulin ✤ IVIG is sourced from a plasma pool of donors and provides polyclonal immunoglobulins to a wide variety of pathogens ✤ Anti-D immunoglobulin is prepared from the plasma of donors who have high levels of anti-D either following exposure to RhD positive cells during pregnancy or intentional immunisation
Cross-matching ✤ Cross-matching refers to the testing for compatibility before transfusion ✤ Determined by ABO, Rh, Kell ✤ Electronic cross-matching relies on computer analysis of tests done on the donor unit of blood and blood samples from the intended recipient ✤ Serological cross-matching requires that red blood cells from the donor blood are suspended in serum from the patient (recipient)