Blood collection and processing Flashcards
Why are donors in Australia voluntary and unpaid?
- bc more likely get altruistic (selfless) donors - continue to donate
- if it was paid it would attract ppl w/high-risk blood born pathogens
What are the two types of donation and what can be produced from each?
- Whole blood: separated into RBC, plasma & plts
2. Apheresis: plasma/plts collected (using aprehesis machine)
Describe the processing of whole blood for transfusion component production.
- blood is centrifuged = plasma, buffy coat (WBC, plt), RBC layer
- placed in a Macropress blood separator = separates plasma & RBC in different bags & buffy coat in original bag
- RBC bag: leukoreduced (removed WBC) & add SAGM (additive solution for storage)
- Buffy coat poled w/ 4 donors w/ same ABO Rh(D) group. Washed w/ plt additive solution (PAS) -> washing collected in a bag -> macropress => separate plt & RBC
What are the comonents in SAGM & function of each?
- Saline: maintain tonicity of solution
- Adenine & Glucose: storage & prodive ADP = maintain viabiltiy (still works)
- Mannitol: prevent haemolysis
What is the benefit of apheresis donation for component production?
cellular components are already separated = no further processing
In which circumstances are transfusions appropriate?
- blood loss
- Anaemic:
• [Hb] < 70g/L in healthy person
• [Hb] 70 - 100 g/L in certain populations
• ACTIVELY BLEEDING & have [Hb] > 100 g/L - replacement of cells e.g. WBC
- replace specific plasma factors
In which circumstances are transfusions inappropriate?
- undiagnosed / asymptomatic anaemia
- post-operative haemoglobin > 80 g/L
- Reversible short - term anaemia (ie. can take medication instead)
- Anaemia responsive to therapy
- Improve general “well-being”
How much should 1 unit of RBCs increase an adult [Hb] by? & significance if not reached
a) ~ 10 g/L
b) <10 g/L may indicate transfusion reaction
How much should 1 unit of platelets increase an adult [plt] by? & significance is not reached
a) 20-50 x 10^9/L
b) <20 x 10^9/L may mean plt are being destroyed
What is the shelf life of RBCs? Platelets? Why is the platelet shelf life shorter?
a) RBC stored @ 2-6ºC for max. 42 days
b) Plt stored @ 20-24ºC for 5 days (w/ gentle agitation)
c) bc stored @ room temp. = inc. risk of bacterial contamination
What are the indications for Fresh Frozen Plasma (FFP)?
- Coagulopathies (where Tx is not available)
- Bleeding patients - require factor replacement
- Warfarin overdose (OD) (prothrombin complex concentrate preferred > warfarin reversal)
What are the indications for Cryoprecipitate administration?
- Dec. plasma [fibrinogen]
- Dysfibrogenaemia
- Disseminated intravascular coagulation (DIC)
Role of Australian Red Cross Lifeblood (ARCLB)
- blood collection
- blood testing
- Component preparation
- Delivery to external parties: CSL & health providers
- Management of blood inventory
how a safe blood is maintatined
- voluntary, unpaid donors
- meet donation criteria: age, height, weight, [Hb]
- Donor Questionaire: health, lifestyle, travel Hx, Medical Hx, declaration
- Screening test for presence of transfusion transmittable pathogens
WHat lab tests are done on donated blood?
- ABO/Rh(D) grouping, Ab screen
- Routine viral screening: Look @ presence of Ag or Ab e.g. HIV Ab, Hepatitis B Ag & C Ab
- Selective screening for malaria & Cytomegalovirus (CMV)
- Not all pathogens are screen e.g. dengue so have questionnaire
What are the risks for transfusion?
Any blood sample may contain pathpgen but risk is very low bc blood is screened & questionnaire must be completed (less than 1: 1 mill risk)
Why is whole blood donated into components?
- bc only require blood components that are needed by the patient
- consider availability & cost
What are the indications for RBC?
- Replacement of traumatic / surgical blood loss
- clinically significant anaemia when other treatment options are not available e.g. Fe, B12
what are the indications for Plt?
- bleeding due to dec. production / functional abnormality
- Post-operative bleeding: <50 x10^9/L
- Thrombocytopaenia 2ºary to other cond. : <10 x 10^9/L
FFP stored @ _ ºC & once thawed must be used w/in _ days
a) -25ºC
b) 5 days
What is cryoprecipitate & how is it stored?
a) Cold-insoluble precipitate of plasma: contains FVIII, vWF, Fibrinogen, FXIII
b) Storage: -25ºC
What is cryoprecipitate depleted plasma & storage?
a) supernatant: plasma contains everything except components in cryo precip.
b) Storage: -25ºC
What are the indications for cryoprecipitate depleted plasma?
- plasma exchange in TTP (replace enzymes & remove Ab)
- Coagulopathies
- Warfarin reversal
