Bleeding disorders Flashcards
What are the four main types of bleeding disorder?
Von Willebrand disease
Haemophilia A
Haemophilia B
Disseminated intravascular coagulation
What is Von Willebrand factor?
A glycoprotein found in blood plasma that plays a role in platelet adhesion
What can Von Willebrand bind to?
Subendothelial collagen
GP IIb / IIIa
What clotting factor is Von Willebrand bound to when inactive in circulation?
Factor VIII
What protein activates VWF to release from Factor VIII and bind to other platelet receptors?
Thrombin
How may patients with a bleeding disorder present?
Which type of VWD does a patient have a complete absence of VWF?
Type 3
(there’s only three types, 3 is most severe)
What drug can be given to patients with VWD in preparation for trauma or surgery?
Desmopressin - stimulates the release of VWF from endothelial cells.
What percentage of people have clinically significant VWD?
0.01%
What causes haemophilia A?
Deficiency in factor VIII
What causes haemophilia B?
Deficiency in factor IX
What type of inheritance are haemophilia A and B?
X-linked recessive (therefore almost exclusively affects males)
When do most cases of haemophilia present?
As neonates or in early childhood
Spontaneous bleeding into which parts of the bodies is a classic feature of haemophilia?
muscles and joints (haemoarthrosis)
How can acute episodes of bleeding be managed in haemophilia?
Infusions of either Factor VIII or IX
Desmopressin to stimulate VWF release
Antifibrinolytics e.g tranexamic acid
