hematologic - coagulation disorders Flashcards
hemophilia A concerns which factor
factor VIII (8)
hemophilia B concerns which factor
factor IX (9)
for surgery, individual clotting factor levels of ____ provide adequate hemostasis
20-25%
what products are available to treat single deficiencies?
factor concentrates, recombinant factors, FFP, gene therapy
how much FFP is needed to obtain a 20-30% increase in the level of any clotting factor?
15-20 mL/kg
hereditary deficiencies
hemophilia A, hemophilia B, von willebrand disease
acquired deficiencies
vitamin k deficiency (antibiotics, intestinal malabsorption, impaired nutrition), liver disease (parenchymal disease), disseminated intravascular coagulation (DIC), autoantibodies
hemophilia A is deficient in factor VIII that affects males or females?
males
severe hemophilia A
<1% factor VIII activity, needs factor VIII concentrate infusions at home
diagnosis of hemophilia A
prolonged aPTT, specific factor testing, and gene testing
anesthesia and hemophilia A
hematology consult, bring factor VIII level >50% prior to surgery, FFP, cryo, TXA
mild - DDAVP 30-90mins prior to surgery
moderate to severe- factor VIII concentrate
half life of Factor VIII
12 hours, but 6 hours in kids so may need redosing for days to weeks after surgery
hemophilia B affects males or females?
males
factor IX levels below ____ are associated with severe bleeding
<1%
mild hemophilia B
levels between 5-40%, isn’t detected until surgery or dental procedure
diagnosis of hemophilia B
prolonged aPTT, specific factor testing, and gene testing
anesthesia and hemophilia B
hematology consult
replacement therapy with recombinant factor IX, purified factor IX, prothrombin complex concentrate
TXA
prothrombin complex concentrate contains which factors
II, VII, IX, X
factor IX half life
18-24 hours
what is the most common congenital bleeding disorder in the world?
von willebrand disease
von willebrand disease is a family of disorders caused by
quantitative and/or qualitative defects
von willebrand factor mediates
platelet adhesion and prolongs factor VIII’s half life
where is VWF synthesized and stored?
endothelial cells, platelets
VWF action
platelet adhesion, platelet aggregation, carrier molecule for factor VIII and cofactor for factor IX
type 1 von willebrand disease
most common (60-70% of patients)
mild-moderate reduction in level of VWF
mild bleeding symptoms
type 2 von willebrand disease
9-30% of patients
qualitative defect of VWF
4 subtypes
type 3 von willebrand disease
<1% of patients, nearly undetectable levels, severe quantitative phenotype
platelet-pseudo type von willebrand disease
defect in the platelet’s GIb receptor
treatment for type 1 von willebrand disease
desmopressin
treatment for type 2 or 3 von willebrand disease
factor VIII concentrate, monitor factor levels, platelet transfusion
replacement therapy goals in von willebrand disease in major surgery
maintain factor VIII level >50% for 1 week
prolonged treatment in type 3 patients >7 days
replacement therapy goals in von willebrand disease in minor surgery
maintain factor VIII level >50% for 1-3 days
and then >20-30% for addt. 4-7 days
replacement therapy goals in von willebrand disease in dental extraction
single infusion to achieve factor VIII levels >50%
desmopressin prior to procedure for type 1
spontaneous or posttraumatic bleeding replacement therapy goal in von willebrand disease
single infusion of 20-40 units/kg
factor VIII and IX deficiency can be treated with
FFP
in disseminated intravascular coagulation (DIC) thrombin
is generated in response to an insulting factor leading to intravascular clotting that disseminates everywhere forming blood clots throughout the body and depleting coagulation factors and platelets, fibrinolysis is also activated and causes bleeding
massive tissue destruction, sepsis, and endothelial injury causes
release of tissue factor
release of tissue factor leads to
widespread microvascular thrombosis that leads to vascular occlusion and ischemic tissue damage
activation of plasmin leads to
fibrinolysis and bleeding
consumption of clotting factors and platelets leads to
bleeding
symptoms of DIC
chest pain, SOB, leg pain, PE, DVT, ekg changes, problems speaking or moving
in DIC hemorrhages occur simultaneously from ___ sites while there is ongoing thrombosis in ____
distant sites; the microcirculation
causes of DIC
sepsis, surgery, trauma, cancer, pregnancy complications, snake bites (venom), frostbite, burns, transfusion reaction
acute DIC
processes of coagulation and fibrinolysis are dysregulated
widespread clotting with resultant bleeding
tissue factor binds with ___ and activates ___ to form ____
FVIIa; IX and Xl; thrombin and fibrin
fibrinolysis creates
fibrin degradation products that inhibit platelet aggregation, antithrombin activity, and impair fibrin polymerization —> BLEEDING
platelet consumption leads to
thrombocytopenia
excess and unregulated thrombin generation causes
consumption of coagulation factors and increased fibrinolysis
excess thrombin in DIC leads to
increased coagulation consumption, decreased anticoagulants, decreased antifibrinolysis, increased fibrinolysis, decreased platelets
blood tests in DIC
low platelets low fibrinogen high PT/INR high PTT high D-dimer
thrombomodulin
binds to thrombin and decreases the proinflammatory response
when would heparin be appropriate for DIC treatment
early or highly prothrombotic states
considerations with heparin administration for DIC
high risk of additive bleeding
shown to reduce end organ dysfunction
DC’d once overt bleeding starts
difficult to monitor because PTT is already prolonged
early hyperfibrinolysis may be treated with
transexamic acid (TXA)
