Bleeding Disorders Flashcards
What are the normal haemostatic mechanisms?
Vessel wall
Platelets
Von Willebrand factor
Coagulation factors
What is the normal haemostatic response?
Primary - platelet plug formation, platelets adhering to abnormal endothelium, become activated and aggregated, rely on vWF
Secondary - eventual fibrin plug formation
Haemorrhagic diathesis occurs due to any qualitative or quantitative abnormality or inhibition of function in what?
Platelets
vWF
Coagulation factors
What are the points you want to establish from a bleeding history?
Has the patient actually got a bleeding disorder?
How severe is the disorder? Context of other illness, trauma, severity etc.
Pattern of bleeding
Congenital or acquired
Mode of inheritance
What do you want to obtain from the history of bleeding?
Bruising
Epistaxis
Post-surgical bleeding - ask about previous surgery or trauma, may need to ask about specific common procedures as patients might not consider them as surgeries
Menorrhagia - has it been present from menarche, common in women with vWF mutation
Post-partum haemorrhage
Post-trauma
What do you want to find out about the severity of bleeding?
How appropriate is the bleeding i.e. is the severity of bleeding consistent with the severity of injury
Completely unprovoked bleeding vs bleeding with obvious cause
Completely unprovoked typically presents at an early age
What do you want to find out about the pattern of bleeding?
Platelet type, thrombocytopenia
- mucosal
- epistaxis
- purpura
- menorrhagia
- GI
- post-surgical bleeding
Coagulation factor
- articular
- muscle haematoma
- CNS
What would you ask to distinguish between congenital or acquired bleeding?
Previous episodes
Age at first event, congenital will present at early age compared to a later date of acquired
Previous surgical challenges
Associated history
What would you ask to determine if the cause of bleeding was a hereditary disorder?
Family members with similar history
Sex of affected individuals - determines kind of inheritance
X-linked - carrier women and affected males
Autosomal dominant - either sex affected
What is the inheritance of haemophilia A and B?
X-linked
Identical phenotypes
What is the incidence of haemophilia type A and B?
1/10,000 type A
1/60,000 type B
In haemophilia, what does the severity of bleeding depend on?
The residual coagulation factor activity
What percentage of haemophilia is severe, moderate and mild?
< 1% severe
1-5% moderate
5-30% mild
Factor VIII and IX genes are on what chromosome?
X
What is the aim for treatment of haemophilia?
To keep factor VIII in moderate levels, to improve quality of life, life-expectancy and reduce spontaneous bleeding
What are the clinical features of haemophilia?
Haemarthrosis - hinge joints most affected, knees and ankles more severely affected than hips
Muscle haematoma - typically in large muscles, especially iliopsoas
CNS bleeding
Retroperitoneal bleeding
Post-surgical bleeding
What are the clinical complications of haemophilia?
Synovitis
Chronic haemophilic arthropathy
Neurovascular compression
Other sequelae of bleeding
How do you diagnose haemophilia?
Clinical presentation e.g. spontaneous bleed into a joint, paediatric
Screening blood tests
- prolonged APTT
- normal PT
- normal bleeding time; detect coagulation deficiencies in different parts of coagulation cascade
Reduced FVIII or FIX depending on which is deficient
Genetic analysis - can help with management and in future pregnancies of carrier individuals
What is the treatment of bleeding diathesis in haemophilia?
Previously always coagulation factor replacement
Now almost entirely done using recombinant products - made in cell lines
DDAVP - releases stored vWF in endothelial cell into the circulation, useful for those who need to have a procedure
Tranexamic acid - also beneficial in major trauma and PPH
Emphasis on prophylaxis in severe haemophilia - converting severe haemophilia to phenotype of moderate haemophilia using recombinant products
Gene therapy
What is the treatment of acute bleeds in haemophilia?
Splints Physiotherapy Analgesia Synovectomy Joint replacement
What are the complications of haemophilia treatment?
Viral infection
- HIV
- HBV, HCV
- vCJD
Development of inhibitors
DDAVP
- MI
- hyponatraemia
What are the features of von Willebrand disease?
Commonest bleeding disorder Incidence 1/200 Variable severity - majority are mild Autosomal inheritance Platelet type bleeding (mucosal) Quantitative and qualitative abnormalities of vWF
What type of deficiency is in von Willebrand disease type 1?
Quantitative deficiency - reduction in normal vWF
What type of deficiency is in von Willebrand disease type 2?
Qualitative deficiency - determined by the site of mutation in relation to vWF function i.e. dependent on part of molecule that is non-functional
