Haemostatic Disorders - Approach & Txt Flashcards
Hemostasis is the process which causes…
bleeding to stop
Coagulation is the formation
of a clot
What are the 4 stages of hemostasis?
Vasoconstriction
Platelet plug formation
Clot formation
Fibrinolysis
Explain the process of hemostasis - Simple.
- Exposed collagen binds & activates platelets
- Platelet factors are released
- Factors attract more platelets
- Platelets aggregate into platelet plug.
What are signs of primary hemostatic disorders?
cutaneous bleeding
mucosal bleeding
excessive bleeding post-trauma or Sx
CNS or ocular bleeding
Primary hemostatic disorders impact blood vessels/endothelium how?
vasculopathy
Vasculitis
increased vessel fragility
Primary hemostatic disorders impact thrombocytopenia how?
- lack platelet production
- increased platelet destruction
- consumption
- sequestration
- loss
What are some ways Primary hemostatic disorders with thrombocytopathy occur?
- hereditary
- drug-induced
- gammopathies
- uremia
- infectious agents
Tests to assess primary hemostasis include…
-hematology and blood smear exam to assess platelet numbers
- BMBT if PLT & coags normal
- vWF assays
- platelet function tests
- viscoelastic testing
- histopath
What are the most common primary hemostatic disorders?
Immune-mediated thrombocytopenia
Von Willebrand’s Disease
Immune-mediated thrombocytopenia is an
acquired condition
Von Willebrand’s diseases is an
inherited disease
immune-mediated thrombocytopenia (IMT) can be
primary/idiopathic
Secondary
If a patient has IMT, what are some very important things that must be remembered when working with that patient?
- No IM, SQ injections
- No jugular samples
- No FNA/cystocentesis, etc.
What txts are available for IMT?
- immunosuppressive therapy/drugs
- IV fluid therapy/blood transfusion
- gastroprotectant if GI bleeding
- supportive txt
What immunosuppressive drug should never be used in cats?
Azathioprine
What are the 3 subtypes of Von Willebrand’s?
Type I: partial quantitative deficiency, residual vWF has normal structure & function
Type II: selective loss of large vWF multimers, decrease PLT-vWF & collagen interactions
Type III: complete vWF deficiency
What are some congenital coagulopathies?
FVIII - Hemophilia A
FIX - Hemophilia B
FXII deficiency
What are some acquired coagulopathies?
- severe protein-losing disorders (PLN, PLE)
- warfarin or heparin admin overzealously
- rodenticide toxicity
- liver insufficiency
What are some tests used to assess secondary hemostasis?
APTT, PT, individual coagulation factor assessments, TEG, ROTEM
What are the most common secondary hemostatic disorders?
- rodenticide toxicity
- liver insufficiency
- DIC
- infectious causes - Angiostrongylus vasorum, lepto
- hemophilia A/B
- feline FXII deficiency
Vit K is an important cofactor for production of…
Factors II, VII, IX, X
What breeds are predisposed to inheriting vit K deficiency?
labradors
devon rex
What is an acquired vit k deficiency?
Rodenticide toxicity
What clinical signs appear with rodenticide toxicity?
Epistaxis
Melena
Hematomas,
Hematuria
Pulmonary bleeding
Hemothorax
Etc.
What are some txts for secondary hemostatic disorder?
supportive txt
whole blood or pRBC transfusion as needed
Vit K txt
replacement of coagulation factors - plasma transfusion
What is a tertiary hemostatic disorder?
An imbalance between activators and inhibitors of fibrinolysis, which results in thrombosis or hemorrhage
What are tests to assess tertiary hemostasis?
- Fibrinogen levels
- Fibrin degradation products (FDPs)
- D-Dimers
- Thrombin Time (TT)
- TEG
TEG or ROTEM are used to assess…
global coagulation
What factors affect TEG/ROTEM?
Thrombocytopenia
low or high RBC/PCV/Hct
Hyperfibrinogemia
Trace of activator & handling conditions
What is one of the most common tertiary hemostatic disorders?
Hyperfibrinolysis in Greyhounds
