Bleeding Disorders Flashcards
Responses in vessel wall damage
Primary
- platelet plug formation
- platelets bind to abnormal surface area for adherence, activation and aggregation
- vWF - bind to cells and surfaces to form an adequate platelet plug
- wall
Secondary
- fibrin plug formation
Mucosal pattern bleeding is caused by what?
Platelets problems
Von Williebrand problems
Presentation of coagulation factor bleeding
Bleed into muscles/joints Different patterns of bleedings into e.g. - knees, ankles - shoulders - elbows - less so hips
Causes of haemorrhagic diathesis
Any quantative or qualitative abnormality Inhibition of function of - platelets - vWF - coagulation factors
What is haemorrhagic diathesis?
The tendency to bleed
History of bleeding - to ask about
Bruises (girls have easy bruising) Epistaxis Post surgical bleeding - dental - circumcision - tonsillectomy - appendicectomy Menorrhagia - VERY relevant - girls who dont have menorrhagia from menarche are then very unlikely to have von Willebrand disease PPH Post trauma FH
Platelet type bleeding will cause….
Mucosal bleeding Epistaxis (both nostrils) Purpura Menorrhagia GI bleeding
Coagulation type bleeding will cause….
Articular - knees, ankles, shoulders
Muscle haematoma
CNS
muscle wasting
What questions to ask to figure out if it is a congenital or acquired bleeding disorder?
Previous episodes
age of first event
previous surgical challenges
associated history
Which factor is affected in haemophilia type A?
factor 8
Which factor is affected in haemophilia type B?
Factor 9
Genetics of haemophilia
X linked
In haemophilia, what does the severity of bleeding depend on?
The residual coagulation factor activity
- <1% = severe
- 1-5% moderate = do not bleed spontaneously
- 5-30% = precautions to be put in place for surgery etc so do not come to too much harm
Presentation of haemophilia
Hemarthrosis - hinge and weight bearing joints Muscle haematoma - calves, biceps particularly CNS bleeding (less common) Retroperitoneal bleeding (less common) Post surgical bleeding - preventable with clinical management
Complications of haemophilia
Synovitis
- can result in loss of articular cartilage due to macrophages in the blood producing an inflammatory response
Chronic haemophilic arthropathy
Neurovascular compression (compartment syndromes)
Other sequelae of bleeding (stroke)
Diagnosis of haemophilia
Clinical - present between 6 months - 2 y/o - baby walking then stops walking (due to bleeding into joints) Screening tests for coagulation - prolonged APTT - normal PT Reduced FVIII or FIX Genetic analysis
Treatment of bleeding diathesis
Coagulation factor replacement FVIII/IX (aim to keep trop > 2%)
DDAVP
tranexamic acid
Emphasis on prophylaxis in severe haemophilia
- 1 every 2 weeks or twice a week for Haemophilia A
Gene therapy
Haemophilia treatment
Splints physio analgesia synovectomy joint replacement
Haemophilia complications of treatment
Viral infection (HIV, HBV etc)
Development of inhibitors
- Anti FVIII Ab (if severe and have no FVIII antigen, will form a response to the coagulation factor replacement)
- rare in FIX as fewer null mutations
DDAVP
- desmopressin (factor 8 and 9 go up for a day which allows you to have surgery etc)
What does desmopressin/DDAVP do?
Promotes the release of von Willebrand factor
What is DDAVP/Desmopressin contraindicated in?
Elderly High risk of vascular disease Children < 3 y/o due to - MI - hyponatraemia (babies)
How common is von Willebrand disease?
Common - 1 in 200
Presentation of von Willebrand disease
Platelet type bleeding (mucosal)
Pathology of Von Willebrand disease, either ….
Quantative (dont make enough)
Qualitive (doesn’t function right)
Types of Von Willebrand disease
Type 1 - quantative deficiency Type 2 (A, B, M, N) - qualitative deficiency determined by the site of the mutation in relation to vWF function Type 3 - severe (complete deficiency)
Treatment of von Willebrand disease
vWF concentrate / factor VIII concentrate or
DDAVP
Tranexamic acid
OCP
Causes of acquired bleeding disorders
Thrombocytopenia Liver failure Renal failure DIC Drugs (the big group of disorders, most common causing bleeding) - warfarin - heparin - aspirin - clopidogrel - rivaroxaban - apixaban - dabigatran
What is thrombocytopenia?
Abnormally low levels of thrombocytes/platelets in blood
Causes of thrombocytopenia
Decreased production
- marrow failure (anaemia and thrombocytopenia symptoms)
- aplasia
- infiltration
Increased consumption
- Immune
- most common - ITP
- non immune DIC
- inappropriate activation of cascade (using up the platelets and coagulation factors)
- burns, sepsis, obstetric emergencies
Hypersplenism
- massive spleen = platelets get stuck in it
- very rarely have a low platelet count (<40)
Presentation of thrombocytopenia
Petechiae - mucosal more dangerous ecchymosis mucosal bleeding rare CNS bleeding
What level of platelet counts are rarely associated with bleeding disorders?
> 40
What does ITP stand for?
Idiopathic thrombocytopenic purpura
What is ITP?
A disorder that can lead to easy or excessive bleeding / bruising - the bleeding resulting from abnormally low levels of platelets
Associations of ITP
Infection (EBC, HIV, glandular fever)
Collagenosis
lymphoma
drug induced (quinine most common)
Treatment of ITP
Steroids
IV IgG
Splenectomy
Thrombopoietin analogues (eltrombopag and romiplostim)
Pathology of liver failure in respect to bleeding
Factor I, II, V, VII, VIII, IX, X, XI
Prolonged PT
APTT reduced fibrinogen
Treatment of liver failure affecting bleeding
Cholestasis Vit K dept factor deficiency
Factor II, VII, IX, X
Replacement FFP
Vitamin K
In liver failure, where does most bleeding occur?
From structural lesions - varices
Pathology of haemorrhagic disease of the newborn
Immature coagulation systems
Vitamin K deficient diet (esp breast)
Fatal and incapacitating haemorrhage
How is haemorrhagic disease of the newborn completely prevented?
1mg IM administration of Vit K at birth
How does tranexamic acid work?
Reversibly binds to lysine receptor sites on plasminogen or plasmin, preventing plasmin from binding to and degrading fibrin
What is the most common inherited bleeding disorder?
Von Willebrand disease
Inheritance of VWD
Autosomal dominant
Type 3 VWD is what type of inheritance?
Autosomal recessive
What % of patients have type I VWD?
80%
What is the most common cause of isolated thrombocytopenia?
ITP
What would make you think of haemophilia A/B?
Hemarthrosis without trauma
