Blood loss & Fluid therapy Dr. Ambrisko Flashcards
What is a blood transfusion
the process of transferring blood or blood-based products from one individual into the cirulatory system of another individual of the same species
Purpose of transfusion
incr. Hgb
incr. volume
incr. albumin
provide coagulation factors
provide platelets
loss of 50% circ vol is fatal but loss of 50% of Hgb may not be
Types of blood products
Fresh whole blood (PCV ≈ 40%)
Packed RBCs (PCV ≈ 70%)
Fresh frozen plasma (FFP)
cryoprecipitate (contains coag factors)
how to incr Hgb content of blood
Whole blood
acute blood loss & TP < 3.5
Packed RBCs
TP >3.5
When should you consider transfusion
Acute blood loss > 20% of blood volume
Clinical signs more important than arbitrary values!
- >10-15 % if loss was perioperative*
- Acute anemia: PCV <20%*
- Chronic anemia: PCV <15%*
- Anemia + Anesthesia: PCV<20%*
CS of blood loss
pale MM
incr HR
decr BP
weak pulse
blood in sponges & suction
Caution: acute bloo loss may not change PCV & TP!
How to estimate blood loss
surgical sponge holds ≈ 5mL of blood
Blood loss (mL) = PCV of suctioned fluid x Volume in canister (mL)
Preoperative pt PCV
How much blood to give
Acute: loss = replacement
General rule: 2ml whole blood / kg BW raises PCV by 1%
- *Blood to be transfused (ml) =**
- *[PCV required – PCV recipient] x blood volume of recipient (ml)**
- *PCV of donor**
How to increase plasma albumin content
Will not be effective if using FFP
consider supplementation with concentrated albumin
Providing coagulation factors
Best option: cryoprecipitate
Fresh whole blood
Fresh plasma
FFP
Providing functional platelets
Use fresh whole blood (plastic container platelets adhere to glass!)
transfuse within 8 hours
considerations for Blood collection
Types of anticoagulant
Plasma separation
Storage
Closed collecting systems
Open system: use blood within 12 hours
Transfusion reactions
incompatibility
anaphylaxis
- alteration of immune system:*
- problems during next transfusion*
- neonatal isoerythrolysis (equine)*
Possible side effects of transfusion
Circulatory overload
Transfusion Related Acute Lung Injury (TRALI)
Citrate induced hypocalcaemia (tetany)
Sepsis (baterial contamination)
Transmission of infectious dz (FIV, FELV, hemobartonella, anaplasma, etc.)
Examining the risk/benefit ratio of transfusions
Give only if absolutely necessary to save life!
Reaction types with blood type incompatibility
Acute
- Hemolysis (horses & cattle)
- agglutination
Slow
Decr RBC life span (few days)
Signs of acute reaction
incr HR, decr BP, incr RR, dyspnea
tremors, vomiting, wheals, urticaria, fever
Pain @ injection site
Hemolysis, Hemoglobinuria, renal failure, DIC
CV collapse
Signs will be less noticible under anesthesia!
Tx of acute reaction
Stop tranfusion!
depending on CS:
Epinephrine IV
Antihistamines IV
Fast acting steroids (?)
Fluids (if needed)
O2 supplementation
Analgesia, etc
Canine blood groups
Dog Erythrocyte Antigen (DEA)
DEA 1.1 & 1.2 incompatibility may cause acute hemolysis
No naturally occurring antibodies, therefore:
1st incompatible transfusion usually uneventful
2nd incompatible transfusion may cause acute transfusion reaction
Feline bloo groups
A, B & AB
- A is common, B rare except in certain breeds*
- naturally occuring antibodies*
1st blood transfusion can be fatal
Blood typing is compulsory!
Mik recently identified 2nd important blood group system in cats
Equine blood groups
Type Aa & Qa most antigenic
Cross matching
serological compatibility
agglutination reaction
Major cross-match: donor RBC + recipient plasma
Minor cross-match: recipient RBC + donor plasma
