Transfusion reactions Flashcards
% of overt transfusion reactions in dogs
3-13%
two types:
immune rxn 5:
non-immune rxn 4:
most common immunologic - FNHTR urticaria hemolytic transfusion reactions immune suppression decreased platelet counts
infectious disease transmission (e.g., Leishmania)
sepsis from bacterial contamination of the unit (e.g., Serratia marcescens)
citrate toxicity leading to hypocalcemia (in patients receiving massive transfusions)
circulatory overload
MoA FNHTR
MoA immune suppression:
residual WBCs in transfused products
= > cytokines in the unit and
WBC - immune suppression (aberrant phagoc in NK)
thrombocytopenia
and acute lung injury in the recipient
increase with storage time
MoA TRALI (transfusion associated lung injury)
HLA (human vs canine leukocyte Ab - HLA antibody in donor plasma
(especially female donors)
=WBC aggregates in the pulmonary circulation leading to hypoxemia, respiratory distress, and often death
Hemolytic transfusion reactions MoA:
- Abs in recipient react w RBC surface Ag of donor
- IgG or IgM antibodies activate complement = membrane attack complex
- damage the lipid bilayer of the RBC membrane leading to intravascular hemolysis
- complement fragments adhering to the RBC surface increase RBC phagocytosis. If leukocytes recognize opsonized RBCs in circulation, the result is intravascular hemolysis, whereas extravascular recognition is termed extravascular hemolysis
Mild transfusion reactions:
type:
Tx:
Prev.:
FNHTR, hypersensitivity reactions to plasma proteins and mild febrile, urticarial, facial edema
diphen., slow down, resume in 15 min
no evidence pre-med helps
Moderate trans. rxn:
type:
Tx:
diphen.?
steroids?
restart?
either hemolytic or nonhemolytic transfusion fever, tachycardia, tachypnea, weakness, vomiting
fluid bolus - stop transfusion
histamine release is not a feature of hemolytic or febrile, nonhemolytic transfusion reactions, unlikely to be of benefit, unlikely to cause harm if administered
may prevent delayed reaction
only if CS resolve within 15 min
Severe transfusion:
cause:
tx:
cats:
anaphylactic shock
dogs -hypotensive collapse
Epinephrine is given for its bronchodilator (cats) and vasoconstrictive (dogs) properties (0.01 mg/kg IV)
boluses
albuterol or epinephrine can be repeated if there is no improvement within 10 minutes
cats -tachypnea
additional dx. with transfusion rxn:
PCV hemolysis and urine hemoglobinuria
recipient
Unit -PCV (hemolysis), gram stain (bacteria), and culture and susceptibility (C&S)
- placed in the refrigerator marked “Do Not Use”
-if infec. immediately begin broad-spectrum bactericidal an
Storage lesions:
- < pH = accum proinflammatory substances, release of free iron, and microparticles containing large amounts of free hemoglobin 2. microparticles
- free Hgb
- > CK
- > free iron
- > ammonia <2-3DPG
free Hgb
potent scavenger of endogenous vasodilator, nitric oxide (NO)
=decreased organ perfusion and MDS
also hypertension
free iron
overwhelm the binding capacities of transferrin and ferritin = oxidative stress
CK
“cytokine soup” promote systemic inflammation and may stimulate transfusion reactions
-accumulation of cytokines in stored blood is significantly decreased by prestorage leukoreduction (CCM adds 35$)
ammonia
only issue in:
> ammonia in canine red cell units from day 1 (73 +/– 15 mmol/L) to day 35 (800 +/– 275 mmol/L)
- no increase in ammonia concentrations was noted in five anemic dogs receiving stored blood that contained elevated ammonia levels
- abnormal hepatic function
Leukoreduction
Canada
shown to lower FNHTR virus transmission alloimmunization immunosuppression inflammation
In dogs, LR has been shown to eliminate the inflammatory response to transfusion,13 decrease microparticle formation compared with non-LR units, and decrease cytokine production compared with non-LR units.7 Leukoreduction is now standard veterinary practice in Canada and most of Europe because of the abundance of evidence supporting a reduced incidence of transfusion reactions and inflammatory responses in the recipients
