Indications and components Flashcards
Why are all anaemic patients not transfused
- evidence in people = improved outcome in restrictive transfusion (Hb 7 -9) maybe pro inflam changes in stored blood.
- expensive, reactions, wasting product
What factors are assessed other than Hb (PCV) when deciding to transfuse
- Major BS and perfusion parameters: Dull mentation, tachycardia (dog), bradycardia (cat), PQ, CRT, tachypnoea.
Monitoring lactate
Why are patients with acute onset anaemia less likely to tolerate low haemoglobin levels
COMPENSATORY MECHANISIMS:
- increased cardiac output
- Resdistribution of blood flow
- increased O2 extraction
- Right shifted oxyhaemoglobin curve.
What in the clinical context might prompt transfusion?
ie situations rather than clin signs
- ongoing blood loss or haemolysis
- Cardiac or pulmonary pathology (less efficient compensatory mechanisms)
- planned anaesthesia (CV depression)
- Planned surgery (risk of blood loss)
how might you decide if an anaemic patient is hypo or euvolaemic
- Hypo may have poor PQ whereas euvolaemic often have bounding pulses.
- euvolaemic have normal CRT (mm still pale)
- Hypovolaemic anaemic patients could have a low but also normal PCV (haemoconcentration)
- TS normal/low in hypovolaemia but usually normal in euvolaemia
What are the two instances when transfusion would be recommended in patients with bleeding disorders?
- severe bleeding, uncontrolled and could lead to hypovolaemia.
- small volume bleeds where organ function is compromised due to location (eg bleeding in the CNS, lung)
- do nt transfuse just to treat prolonged clotting times
what products can be useful in treating primary vs secondary coagulopathy
- Primary = platelets or vWF; whole blood, platelet concentrate FP/FFP and cryoprecipitate
- Secondary = factors; FP/FFP (cryopreciptate or cryopoor depending on the factor)
What is the difference between how FP and FFP are made and stored.
- FFP separtated and frozer withing 8 hours of collection. stored for up to 1 year.
- FP has been either stored for > 1 year, not been frozen within 8 hours of collection or is FFP which has thawed and refrozen
Which are the liable clotting factors
Mainly factors 5 and 8
What are the indications for and the storage requirements of packed red cells
- for euvolaemic anaemia or hypovolaemic anaemia whith additional fluids to resusitate.
- refridgerated at 4 defrees for 35- 42 days
- standard dose of 6 - 10ml/kg
What does FFP contain and when is it indicated
- contains all stable and liable clotting factors, vWF and plasma proteins
- can be used for any disease of secondary haemostasis or VWD.
- Might be eccomonical to reserve for factors 5, 8 haemophilia etc
What does FP contain and when is it indicated
Stable clotting factors only and some plasma proteins
- anticoagulant rodenticide tox, coagulopathies not involving 5, 8 or vWD, volume expansion
What is cryoprecipitate and what are its indications for use
- Further separation of FFP by slow thaw and centerfuge.
- contains factor 8, vWF and fibrinogen.
- used to treat haemophilia A or vWD
What is crypoor plasma and what are the indications
- It is what is left when FFP is processed to make cryoprecipitate.
- indications as per FP (coagulopathies not involving 8, 5 or vWF)
How does plasma effect COP, what is the value of plasma for oncotic support?
- COP of the healthy patient is 21-25mmHG which is the same as plasma.
- COP of Voluven is 37mmHG, therefore plasma less efficient at raising but associated with less negative effects.
may need large volumes and be expensive.
maybe used crystalloid sparing
Why is low albumin a problem in illness
- decreases COP so predisposed to interstitial oedema.
- poor tissue healing
- Reduced binding capacity of drugs
What is the use and limitations of using plasma to increase albumin
- contains physiological levels so large volumes required, so risk of fluid overload and expensive.
- approx 22.5ml/kg plasma required to raise ALB by 5g/dl
What is platelet transfusion difficult
Platelets are activated and destroyed during blood collection, storage and in the recipient
What uk options exisit for platelet transfusion
- fresh whole blood
- PBB platelet concentrate (ideally order use same day.sort shelf life agitate at roop temp for max 3 days)
What are the limitations of albumin transfusion
- HSA expensive and can cause fatal reactions.
What are some important consideration for storing PRBC
- No rough handling could rupture cells
- 4 degrees, constant temp monitoring in a rarely opened fridge.
- Bags are upright with space for air to circulate.
- mixed by gentle inversion several times weekly.
what changes do PRBC undergo whilst stored
- depletion of 2, 3 DPG ATP and nitric oxide
- acummulation of pro inflammatory substances, such as reactive oxygen species.
