1. Blood Transfusion Products

2. Learning Objectives  To identify the products that can be derived from whole blood donations  To describe the conditions that can be treated with blood transfusion products  To describe the screening process of blood products

3. Blood Donation Products

4. Whole blood  In most circumstances, blood component therapy has replaced the use of whole blood.  However, whole blood is still occasionally used for massive transfusion in circumstances in which rapid correction of acidosis, hypothermia and coagulopathy is required.  This mainly occurs in military situations for trauma patients who require resuscitation.

5. Red Blood Cells  RBCs are prepared from whole blood by removal of most of the plasma.  They are indicated in both acute haemorrhage and chronic anaemia.  Red cell units have a haematocrit of 70%  Shelf life of 35 days and 42 days respectively when refrigerated at 1-6°C.

6. Platelets  Each unit of platelets is prepared from a single whole blood collection by differential centrifugation and contains at least 5.5 x 10 10 platelets in 50 ml of plasma.  They are stored at 20-24°C in plastic containers under agitation and have a shelf life of five days.  Each unit can raise platelet count by 5-10 x 10 9 /L.  Platelets are not usually cross-matched with the recipient, but ABO type-specific platelets should be provided where possible.  Platelets are given to patients with thrombocytopenia who are bleeding or those with severe thrombocytopenia.

7. Granulocytes  These are mainly given to neutropenic cancer patients developing bacterial sepsis unresponsive to conventional antibiotic therapy for at least 24-48 hours.neutropenic  Granulocyte preparations can only be stored for 24 hours at 20-24°C.  They need to be cross-matched with the recipient's serum because of the large number of red cells they contain  Granulocytes are only usually considered for patients with an absolute neutrophil count <0.5 x 10 9 /L and a good chance of marrow recovery

8. Fresh Frozen Plasma  FFP is produced by centrifugation of one donation of whole blood, and collecting the supernatant liquid. [4]4  The plasma is frozen within eight hours of collection, in order to maintain the activity of factor V and factor VII  The main indication for FFP is deficiency of multiple coagulation factors found in liver disease and disseminated intravascular coagulation (DIC)  It is also often used for urgent reversal of warfarin anticoagulationwarfarin

9. Albumin  This is available as 5% or 25% solution for the treatment of hypovolaemia and hypoalbuminaemia.  The cost-benefit of albumin in the treatment of hypovolaemia is controversial but it is still used in the management of liver disease and ascites.  It is tested for hepatitis C virus (HCV) RNA and virally inactivated, and not considered as a risk factor for viral transmission.  Its use has now largely been superseded by non-plasma colloidal solutions

10. Immunoglobulins  Intravenous (IV) immunoglobulin is used in the treatment of immuno-thrombocytopenia, Guillain-Barré syndrome and autoimmune haemolytic anaemias.  RhD immunoglobulin is used to prevent exposure to D-positive red cells causing Rh sensitisation in D-negative patients.  This is usually given in pregnancy and immediately after birth to prevent haemolytic disease of the newborn in future babies.

11. Factor VIII  Also known as human antihaemophilic fraction, this is prepared from human plasma by a suitable fractionation technique and indicated for the treatment and prophylaxis of haemorrhage in haemophilia A.  Large or frequently repeated doses in patients with blood groups A, B or AB can lead to intravascular haemolysis, this is less likely to occur with high-potency purified concentrates.  Side-effects include allergic reactions, chills and fever. [4]4

12. Screening Process

13. Prior to donation  Donors are typically required to give consent for the process and this requirement means minors cannot donate without permission from a parent or guardian  If a potential donor does not meet these criteria, they are 'deferred'.  The donor's race or ethnic background is sometimes important since certain blood types, especially rare ones, are more common in certain ethnic groups.

14.  In 2011, the UK reduced its blanket ban on MSM donors to a narrower restriction which only prevents MSMs from donating blood if they have had sex with other men within the past year.  Donors are examined for signs and symptoms of diseases that can be transmitted in a blood transfusion, such as HIV, malaria, and viral hepatitis.  Screening may include questions about risk factors for various diseases, such as travel to countries at risk for malaria or variant Creutzfeldt-Jakob Disease (vCJD).

15.  The donor is also examined and asked specific questions about their medical history to make sure that donating blood is not hazardous to their health.  The donor's hematocrit or hemoglobin level is tested to make sure that the loss of blood will not make them anemic, and this check is the most common reason that a donor is ineligible.  Pulse, blood pressure, and body temperature are also evaluated

16. Post Donation  The donor's blood type must be determined if the blood will be used for transfusions  The collecting agency usually identifies whether the blood is type A, B, AB, or O and the donor's Rh (D) type and will screen for antibodies to less common antigens.  More testing, including a crossmatch, is usually done before a transfusion.

17.  Most blood is tested for diseases, including some STDs.  The tests used are high-sensitivity screening tests and no actual diagnosis is made.  The blood is usually discarded if these tests are positive  The donor is generally notified of the test result

18.  Donated blood is tested by many methods, but the core tests recommended by the World Health Organization are these four:  Hepatitis B Surface Antigen  Antibody to Hepatitis C  Antibody to HIV, usually subtypes 1 and 2  Serologic test for Syphilis  A variety of other tests for transfusion transmitted infections are often used based on local requirements. Additional testing is expensive.

19.  Cytomegalovirus is a special case in donor testing in that many donors will test positive for it. The virus is not a hazard to a healthy recipient, but it can harm infants[ and other recipients with weak immune systems.