Blood Loss and Transfusions Flashcards
What is a blood transfusion?
Transferring blood or blood based products from one individual to another of the same species
What is the purpose of a transfusion?
- Increase Hb content of blood
- Increase circulating volume
- Increase plasma albumin content
- Provide coagulation factors
- Provide functional platelets
What is the percentage of blood loss that is fatal?
50% total volume
Is losing 50% of hemoglobin fatal?
May not be but depends on the individual
What are the types of blood products?
- Fresh whole blood
- Packed red cells
- Fresh frozen plasma
- Cryoprecipitate
- Platelet rich plasma
What PCV does it have to be to be considered whole blood versus packed red cells?
Whole blood- 40%
Packed red cells- 70%
How do you increase Hb content of blood if TP is
Fresh whole blood
How do you increase Hb content of blood if TP is >3.5?
Packed red cells
How long do RBCs survive normally?
60-120 days
Less if there is an immune reaction
What is the percentage loss needed to require transfusions in an acutely bleeding patient?
> 20% total volume
>10-15% if perioperative
Transfusions are requred at which PCV values for:
Acute anemia, chronic anemia, anemia with anesthesia
Acute anemia-
Are clinical signs or values more important when considering transfusions?
Clinical signs
Is a higher or lower Hb content needed in cases of organ dysfunction?
Higher!
What are the clinical signs of blood loss (acute or chronic)?
- Pale MMs
- Elevated HR
- Low BP
- Weak pulses
- Blood in surgical sponges or containers
Will acute blood loss always result in changes in PCV and TP?
No! Not reliable
How much blood does a standard surgical sponge contain?
~5mL
How is blood loss calculated from fluid in canisters?
mL= (PVC fluid x Vol fluid)/ Preop PCV
How much blood volume should be given in acute blood loss?
The same amount that was lost
What is the general rule for increasing PCV?
2mL whole blood/kg raises PCV by 1%
What is the calculation for volume of blood to be transfused?
([PCVreq-PCVhave]xblood volume)/PCVdonor
What are the empirical dosages for transfusions in dogs and cats?
10-40mL/kg Dogs
5-20 mL/kg Cats
What dosage should be started to test?
0.25mL/kg for 30 min to test reaction then it can be increased
When should a transfusion be completed by?
Within 4 hours
Can blood be mixed with LRS?
No- blood will clot due to Ca content