CP38 - Acquired Bleeding Disorder Flashcards
how can you determine whether the clotting factors are deficiency or inhibitor?
APTT test repeat with 50:50 patient to normal plasma - if deficiency, then the normal clotting factor in blood will correct the clotting factor if no correction then inhibitors present
why does patient with liver diseases have low platelet count
because 1/3 platelet sit on the spleen and liver disease might block the duct so spleen can not be released
what are the Vit K dependent clotting factors?
clotting factos II, VII, IX, X
where are all the clotting factors synthesed in the body?
liver
what happens to the clotting factors II , VII, IX, X when they are finished synthesised in the liver?
gemma glutyl carbroxylase add on the ending to the factors which are essential to the activity
what happens to the VIt K after the step of adding proteins by gemma glutyl carbroxylase
they become Vit K epoxide which is not usable as a co-factor for gemma glutyl carbroxylase
what enzyme return VIt K epoxide to Vit K
Vit K reductase
what enzyme does warfarin affect
Vit K reductase
how can Vit K be absorbed
fat soluble ie by intestine
what can cause Vit K deficiency
obstructive jaundice
prolonged nutritional deficiency
broad spectrum antibiotics
neonates (classical 1-7 days)
what does bacteria in gut do to Vit K
absorb them
what can cirrhotic coagulopathy cause?
liver produce all the clotting factors and so damage to liver = reduction to clotting factor production
what can liver impairment cause to haemostatsis
impaired - thrombocytopenia, platelet dysfunction, reduction plasm conc of all coagulation factors expect factor 8
definiton for massive transfusion
transfusion of a voluime equal to the patient’s total blood volume in less than 24 hours
or
50% blood volume loss within 3 hrs
why does massive transfusion syndrome happen
because when transfusing only blood cells are transfused
how can massive transfusion affect haemostasis
Due to dilutional depletion of platelets and coagulation factors
Due to DIC - risk factors are extensive trauma, head injury, prolonged hypotension
Due to underlying disease, eg liver or renal drug treatment or surgery
which clotting factor usually deplete first in massive transfusion?
factors 5 & 8 & fibrinogen
what is the DIC
Disseminated Intravascular Coagulation
what is the underlying pathogenesis of DIC
Generalised disruption in the physiological balance of procoagulant and anticoagulant mechanisms.
what happens in DIC
Consumption of clotting factors and platelets.
Microvascular thrombosis: tissue ischaemia and organ damage
Activation of fibrinolysis
Microangiopathic haemolysis - due to the fibrinolysis digesting on clotting factors
what are some causes to acute DIC
sepsis
obsteric complications
trauma/tissue necrosis
acute intravascular haemolysis eg ABO incompatbile blood transfusion
what are some cause chronic DIC
Malignancy
End stage liver Disease
what are the management of DIC
treat underlying cause
supportive treatment
main tissue perfusion
