Bleeding Disorders Flashcards
Causes of excess bleeding (not surgical or from diseases after atherosclerosis)
Over-anticoagulation
Disseminated intravascular coagulation
Platelet disorders
Pathophysiology of over-anticoagulation
Anticoagulation causes the blood to inappropriately avoid clotting -> Bleeding
What factors are blocked by Warfain?
2, 7, 9, 10
Aetiology of over-anticoagulation
Iatrogenic
inappropriate prescription of warfarin or heparin
Treatment of patients with excess bleeding as a result of warfarin overdose
Phytomenadione
Treatment of patients with excess bleeding as a result of heparin overdose
protamine sulfate
What is meant by disseminated intravascular coagulation
Coagulation systems (thrombin) activated inappropriately
Clinical presentation of disseminated intravascular coagulation
Underlying condition treat
Bleeding from unrelated sites (ENT, GI, response, site of venipuncture)
Confusion, fever
Skin: Purpura, petechiae, localised infarction
Pathophysiology of Disseminated Intravascular Coagulation
Clotting occurs inappropriately and diffusely, until clotting factors are exhausted.
At this point uncontrolled bleeding occurs
Aetiology of Disseminated Intravascular Coagulation
Secondary to infection, malignancy, major trauma
Diagnostic tests of Disseminated Intravascular Coagulation
Prothrombin time elevated
Activated partial thromboplastin time elevated
Platelets low
Fibrinogen low
Treatment of Disseminated Intravascular Coagulation
Consider transfusion of platelets
Complications of Disseminated Intravascular Coagulation
Organ failure by infarction, death
Examples of platelet disorders
Immune thrombocytopenic purpura
Thrombotic thrombocytopenic purpura
Clinical presentation of Immune thrombocytopenic purpura
Rapid onset of purpura (usually self limiting in children).
Easy bruising, epistaxis and menorrhage.
Major haemorrhage is rare.
What is Immune thrombocytopenic purpura
Immune destruction of platelet cells
Pathophysiology of Immune thrombocytopenic purpura
Formation of antibodies against platelets -> Autoimmune Platelet destruction -> thrombocytopenia. The spleen is the site of autoantibody
What are purpura
A rash of purple spots on the skin caused by internal bleeding from small blood vessels
Children Aetiology of Immune thrombocytopenic purpura
a result of viral infection
Adult aetiology of Immune thrombocytopenic purpura
occurs in combination with another autoimmune condition (SLE etc)
Epidemiology of Immune thrombocytopenic purpura
5/100,000 in children
2/100,000 in adults
Diagnostic test of Immune thrombocytopenic purpura
FBC - isolated thrombocytopenia
Treatment of Immune thrombocytopenic purpura
Oral corticosteroids (prednisolone) Second line: splenectomy
Clinical presentation of Thrombotic thrombocytopenic purpura
Florid purpura Fever Fluctuating cerebral dysfunction Haemolytic anaemia Often renal failure
Pathophysiology of Thrombotic thrombocytopenic purpura
Deficiency of ADAMTS 13 (protease which degrades vWF) -> Widespread adhesion and aggregation of platelets -> microvascular thrombosis -> profound thrombocytopenia
Aetiology of Thrombotic thrombocytopenic purpura
Congenital (genetic absence of ADAMTS 13) or autoantibody mediated (autoantibody against ADAMTS 13)
Diagnosis of Thrombotic thrombocytopenic purpura
Raised lactate dehydrogenase levels (from ischaemic or necrotic cells)
Treatment of Thrombotic thrombocytopenic purpura
Plasma exchange to remove autoantibodies to ADAMTS 13
Splenectomy as a last resort