Bleeding Disorders Flashcards
Normal haemostatic mechanisms
Vessel wall
Platelets
vWF
Coagulation factors
vWF
von Willebrand Factor
Primary haemostatic response
Platelet plug formation
Secondary haemostatic response
Fibrin plug formation
What is haemorrhagic diathesis?
An unusual susceptibility to bleed mostly due to hypocoagulability
History of bleeding
Bruising Epistaxis Post-surgical bleeding Menorrhagia Post-partum haemorrhage Post-trauma
How is severity of bleeding disorders determined?
How appropriate the bleeding is
What is the platelet type pattern of bleeding?
Mucosal bleeding Epistaxis Purpura Menorrhagia GI bleeds
What is the coagulation factor pattern of bleeding?
Articular bleeding
Muscle haematoma CNS
How can you tell petechiae are petechiae?
They dont blanche
What is coagulation factor VIII deficiency?
Haemophilia A
What is coagulation factor IX deficiency?
Haemophila B
How are haemophilias A and B inherited?
X-linked
What is severe haemophila?
Spontaneous bleeding
<1% factor activity
What is moderate haemophila?
Bleeds only with provocation (never spontaneous)
1-5% factor activity
What is mild haemophilia?
5-30% factor activity
Clinical features of haemophilia
Haemarthrosis Muscle haematoma CNS bleeding Retroperitoneal bleeding Post surgical bleeding
Which joints are more affected by haemophilia?
Ankle and knee joints - weight bearing
Hip joints less affected
Hinge joints moree affected than ball and socket
Complications of haemophilia
Synovitis
Chronic Haemophilic Arthropathy
Neurovascular compression (compartment syndromes)
Other sequelae of bleeding (Stroke)
How does haemophilia cause synovitis?
Macrophages in joint eat blood and release cytokines - synovial hypertrophy - lose joint cartilage
Haemophilia treatment of bleeding diathesis
Coagulation factor replacement
Prophylaxis in severe haemophilia
General haemophilia treatment
Splints Physiotherapy Analgesia Synovectomy Joint replacement
Haemophilia treatment complications
Viral infection (HCV from transfusion before 1987) DDAVP - MI/hyponatraemia in babies
What is the inheritance of von Willebrand disease?
Autosomal dominant
What type of bleeding does von Willebrand disease involve?
Platelet type bleeding
What is type 1 vW disease?
Quantatitive deficiency
What is quantatitive deficiency?
Don’t have enough of all of vWF
What is type 2 vWD?
Qualitative deficiency - determined by the site of mutation in relation to vWF function
What is type 3 vWF function?
Severe (complete) deficiency
DDAVP
Desmopressin
Used to help stop bleeding in patients with von Willebrand’s disease or mild hemophilia A
Causes the release of von Willebrand’s antigen from the platelets and the cells that line the blood vessels where it is stored
What is vWF?
The protein that carries factor VIII
Treatment of vW disease
vWF concentrate or DDAVP
OCP etc
Acquired bleeding disorders
Thrombocytopenia Liver failure Renal failure DIC Drugs
Causes of thrombocytopenia
Decreased production
Increased consumption
What is thrombocytopenia?
Low platelet count
Causes of decreased platelet production
Marrow failure
Aplasia
Infiltration
Causes of increased consuption of platelets
Immune ITP
Non immune DIC
Hypersplenism
ITP
Immune thrombocytopenic purpura
A bleeding disorder in which the immune system destroys platelets - blood isolated thrombocytopenia
DIC
Disseminated intravascular coagulation
Condition in which blood clots form throughout the body, blocking small blood vessels
Clinical presentation of thrombocytopenia
Petechia
Ecchymosis
Mucosal bleeding
Rare - CNS bleeding
Ecchymosis
Discoloration of the skin resulting from bleeding underneath, typically caused by bruising
What is the most likely location of petechiae?
Ankles
Associations of ITP
Infection esp EBV, HIV
Collagenosis
Lymphoma
Drug induced
Treatment of ITP
Steroids
IV IgG
Splenectomy
Thrombopoietin analogues
NOT transfusion as problem is that immune system is destroying platelets so adding more won’t help
Which clotting factors are made in the liver?
I, II, V, VII, VIII, IX, X, XI
APTT
Activated partial thromboplastin time - blood test that characterises coagulation of the blood
PT
Prothrombin time
How long it takes the blood to clot
PT and APTT in liver failure
Prolonged
Vitamin K dependent clotting factors
II, VII, IX, X
How is haemorrhagic disease of the newborn prevented?
IM vitamin K administered at birth
