Acquired bleeding disorders Flashcards
Most prevalent between acquired and inherited coagulation disorders
Acquired more common than inherited
How many coagulation factors are affected in acquired coagulation disorders
More than 1
Classification of acquired coagulation disorders
Deficiency of vitamin k liver function related Antibody induced Drug/transfusion induced Interference from abnormal proteins Consumptive coagulopathy
Why will a deficiency of vitamin k cause coagulation disorders
This is because some coagulation factors are vitamin k dependant
How does poor liver function cause coagulation disorders
This is because a lot of coagulation factors are produced in the liver.
Hepatitis, cirrhosis, hepatocellular ca etc
How do antibodies cause coagulation disorders
Antibodies can be produced against certain factors necessary for coagulation
Vitamin K is important in the synthesis of these coagulation factors
factor 2, 7,9, 10
which are important factors in all the pathways, hence without it none of the pathways can function
Sources of vitamin k
green vegetables, bacterial synthesis in the gut
In what circumstances does vitamin k deficiency occur
Newborn
Biliary obstruction
Malabsorption
Inhibition of vitamin k
Why does vitamin K deficiency occur in the newborn
Newborn does not eat green vegetables, and their gut is not well developed to synthesize vitamin k
Breast milk contains low amount of vitamin k
Causes of malabsorption syndrome
surgery, tropical sprue, gluten sensitive enteropathy
warfarin and vitamin k
warfarin is a vitamin k antagonist
The abscence of vitamin k leads to the production of
PIVKA. Protein induced in vitamin k absence which in themselves lead to a bleeding tendency
Antibodies being produced against certain factors may be
Induced or spontaneous
Von willebrands disease is
Autoimmune with antibodies being produced against von willebrands factor
How does massive transfusion cause coagulation disorders
They dilute coagulation factors of receiver. Donors blood does not carry all the factors due to duration of preservation etc .
Anticoagulants are present in blood during preservation to keep it from clotting. massive transfusion will cause anticoagulant effect to be pronounced.
How does interference from abnormal proteins cause coagulation factor disorder
Abnormal proteins like plasma cell myelomas and paraproteins coat the surface of platelets leading to poor function
They also interfere with fibrin formation
Initiators of consumptive coagulopathy
vessel wall damage
tissue factor release
platelet aggregation
Initiators of consumptive coagulopathy
infections malignancies obstetric complications Hypersensitivity reaction widespread tissue damage vascular abnormalities hypothermia heat stroke acute hypoxia
Haemorrhagic disease of the newborn
Acquired bleeding disorder in the newborn
What causes HDN
Vitamin k deficiency
Liver cell immaturity
Presentation of HDN
Bleeding from second to fourth day of life
Diagnosis of HDN
Normal platelet count
Prolonged PT
Prolonged APTT
Prophylaxis for HDN
Vitamin K
Treatment for HDN
1mg of vitamin K every 6 hours
In case of severe bleeding use prothrombin complex concentrate
What causes bleeding in patient with liver dx
Biliary obstruction leads to impaired absorption of vitamin k which is fat dependent
Vitamin k dependent factors are affected
Dysfibrogenemia
Reduction of other coagulation factors
DIC
Oesophageal varices
Diagnosis of liver dx
Underlying dx features
Deranged liver enzymes
Reduced albumin
Raised PT and APTT
Prophylaxis for liver dx
5mg/day Vitamin K
If person is bleeding in liver dx
10mg iv vitamin k slowly
Prothrombin complex
Fresh frozen plasma
DIC
Coagulation system triggered into overdrive with coagulation factors used up and reduced in number and the formation of microthrombi in the vascular system
DIC characterised by
End organ damage Bleeding Consumption of platelets Thrombotic syndrome gangrene
Investigation of DIC
Check for underlying disease
Full blood count i.e low platelets, fibrinogen, increased PT,APTT, fibrin degradation products, D-dimers
Hemolytic anemia due to microangiopathy
Treatment of DIC
Treat underlying cause Treat bleeding with ; FFP Platelets Cryoprecipitate Red cells Treat thrombus with heparin
