Blood and Blood Products Flashcards
Define a blood component
A blood product manufactured in a local blood centre that is derived from a single donation or a small pool (4-6) of donations
Red cells, platelets, FFP
Define plasma derivative
blood product manufactured from a large pool of plasma donations (1000s) using industrial type systems
Priorities for the national blood service
- Min risk to recipients of blood products and to the crown (liability)
- Responsive to situations e.g. emergencies or potential infection risks
- Strategic direction and leadership
- Nationally consistent and accessible service
- protection of the gift status of blood
CSL Behring Australia
- Plasma fractionator in melbourne
- Receives plasma from NZBS and manufactures into a range of plasma derivatives for use in NZ
Products: - Factor VIII (Biostate)
- Factor IX (MonoFIX, ProthrombineX)
- IV immunoglobulin (Intagram P)
- Human Albumin solution (Albumex)
Strategies for maintaining a safe blood supply
use voluntary non-enumerated donors
Exclusion of potential donors who’s behaviour or lifestyle places them at increased at risk of acquiring recognised blood borne infections
Testing all blood donations for evidence of major blood borne viruses
Use of physical and chemical methods to destroy any pathogens that maybe present
Examples of infections transmissible by blood
- Viruses
- Protozoa
- Bacteria
- Hep, HIV, Epstein- Barr
- Malaria, toxoplasma gondii
- Syphyllis, staph and strep, salmonella
Paid donation associated with?
Increased risk of blood borne virus transmission
Exploitation of the poor and disadvantaged
The precautionary principle
Risk is inherent in the use of blood products, it can never be said that there is absolutely no risk and that it is perfectly safe
Preventative agent should be taken when there is evidence that a potential disease causing agent may be blood borne, even when there is no evidence that recipients have been affected.
If harm can occur it should be assumed that it will occur
Donor eligibility criteria
between 16-70 good general health able to donate blood every 12 weeks - complete health questionarre - interview with a registered nurse - Hemoglobin check
Donor selection aims to protect
The potential recipient
- identify medical and lifestyle factors that might increase the risk to the potential recipient
The Donor
- Identify health problems that might increase risk of complications from donation
In NZ all donations tested for?
ABO, Rh(d) type and antibody screen
Hep B surface antigen and nucleic acid test for HBV DNA
HIV 1/2 antibody and nucleic acid test for HIV-1 RNA
HTLV antibody (first time donors only)
Serological test for syphilis
Mian clinical indication
- Red cells
- Platelet concentrations
- FFP
- Improve oxygen delivery to tissues in cases of anaemia or blood loss
- Management of prevention of bleeding in patients with low platelet counts
- Correction of abnormal coagulation on patients who are bleeding
Restrictive vs conservative transfusion
use associated with at least as good clinical outcome, now check their Hb after giving each unit, to see whether they need another one
Danger of using ‘older’ red cells?
One retrospective study of clinical outcomes found increased risk of postoperative complications when patients given blood two weeks or older.
However this study has been debunked
To date all control trials have failed to demonstrate any benefit from using fresh vs older blood
The factors to consider when deciding whether to transfuse red cells
Signs and symptoms of hypoxia Ongoing blood loss Risk of anaemia to patient Risk of transfusion Hemoglobin, although important shouldn't be the deciding factor
Red cell transfusion, specific factors to consider
Patients Cardiopulmonary reserve
- If pulmonary function not normal, consider transfusing at a higher threshold
Volume of blood loss
- clinical assessment should attempt to quantify the volume of blood loss before, during and after surgery, to ensure maintenance of normal blood volume
Oxygen consumption
- Affected by fever, anaesthesia and shivering
- If increased, patients may need more RBC’s
Atherosclerotic disease
- Critical arterial stenosis to major organs, particularly the heart may modify indications may modify indications for the use of red cells
Hb levels and transfusion
<70g/L lower thresholds acceptable in patients without symptoms and where specific therapy available
70-100g/L appropriate during surgery associated with major blood loss, if there are signs or symptoms of impaired oxygen transport
>80g/L appropriate to control anaemia related symptoms in a patient on a chronic transfusion regime, or during marrow suppressive therapy
>100g/L not likely appropriate
Describe platelet concentrations
A adult therapeutic dose: pool form 4 donations, or an aphaeresis machine donation
Specific component manufactured for neonatal use
Platelet con’s manufactures only from group O and A donors
What is the normal platelet count?
150-400x10^9/L
Indications for platelet transfusion
PROPHYLAXIS
Bone marrow failure
<10^9/L when NO risk factors present
<20x10^9 when fever and other risk factors present
Surgery and other invasive procedures
<50x10^9/L for normal surgery
<100x10^9/L for high risk surgeries e.g. ocular and neuro
Platelet function
may be appropriate in inherited and acquired disorders, platelet count unlikely to be helpful
Indications for platelet transfusion
Patient bleeding
- When platelet count below trigger level and significant bleeding
Massive haemorrhage/ transfusion
- use confined to patients with low platelet counts and or functional abnormalities, who have significant bleeding from this cause
- May be appropriate when count 50x10^9/l in presence of diffuse microvascular bleeding
Describe FFP
Plasma from single donation frozen within 6 hours of collection to <20 deg celsius
Vol approx 200ml
Initial dose where indicated 12-15ml/Kg
NZBS currently manufactures all FFP from male apheresis donors
Evidence from clinical audits indicates a significant level of overuse
Donor and recipient matches (in terms of blood groups for FFP)
Opposite to red cells!! O from AB, A and B (and O if it was collected but its not) A from A and AB B from B and AB AB only from AB
Indications for FFP
Replacement of single factor deficiencies where specific or combined factor concentrate not available
Immediate reversal of warfarin effect in the presence of potentially life threatening bleeding
Treatment of the multiple coagulation deficiencies associated with acute DIC
Treatment of thrombotic thrombocytopenia purpura
Treatment of inherited deficiencies of coagulation inhibitors in patients undergoing high-risk procedures where a specific factor concentrate not available
In bleeding patients with abnormal coagulation parameters following massive transfusion, cardiac bypass surgery or liver disease
FFP not considered appropriate as?
volume expander in cases of hypovolemia
Plasma exchange procedures
Treatment of immunodeficiency states
How are plasma derivatives manufactured?
industrial processes involving large plasma pools
Highly regulated
1-2 viral inactivation steps
good safety profile
