Inherited Bleeding Disorders Flashcards
what is an inherited bleeding disorder?
an acquired defect which affects the coagulation of the blood
what are the different ways in which an inherited bleeding disorder can prevent the coagulation of blood?
- affects the coagulation cascade
- affects the platelets
- affects both of the above
what occurs in an inherited bleeding disorder that affects the coagulation cascade?
- a reduction in one or more of the coagulation factors or control proteins
what is Haemophilia?
too LITTLE clot formed
what is Thrombophilia?
too MUCH clot formed
what occurs when an inherited bleeding disorder affects the platelets?
affects the number and function of platelets
what disorder results in the deficiency of clotting factor VIII?
Haemophilia / Haemophilia A
what clotting factor is affected in patients suffering with Christmas disease / Haemophilia B?
factor IX deficiency
what occurs in patients suffering with von Willebrand’s disease?
- reduced factor VIII level
- reduced platelet aggression
what coagulation factor deficiency is common in the Ashkenazy Jew population?
factor XI definitely
what type of disease are Haemophilia A & B?
Inherited sex-linked recessive diseases
what chromosome is affected in Haemophilia A & B?
- defective gene on the X chromosome
- therefor males are affected & females are carriers
what is the severity of Haemophilia A/B dependent on?
depends upon the amount of factor produced: 1iu (international unit) is ‘normal’
describe the concentration of coagulation factor in a person with severe haemophilia A/B?
< 0.02in/ml (less than 2% activity)
describe the concentration of coagulation factor in a patient with moderate haemophilia?
0.02-0.09 iu/ml (2-9% activity)
describe the concentration of coagulation factor in a patient with mild haemophilia?
0.1-0.4 iu/ml (10-40%)
what would the concentration of coagulation factors look like in a carrier of haemophilia?
<0.5 in/ml (more than 50% activity)
what is the ‘normal’ clotting factor international unit value in healthy patients?
1iu
how is severe Haemophilia A managed?
- requires the use of recombinant factor VIII (clotting factor 8 that is produced in a library)
how are patients with mild haemophilia/carriers of the disease managed?
- occasional use of DDAVP
- very mild cases may only require oral tranexamic acid
what is DDAVP?
releases factor VIII that has been bound to endothelial cells giving a temporary boost to Factor VIII levels and clotting ability
what is tranexamic acid?
- inhibitor of fibrinolysis
- keeps any clot that is formed
how is Haemophilia B managed in severe and moderate cases?
requires the use of recombinant factor IX
how is Haemophilia B managed in mild cases and carriers?
ALSO requires the use of recombinant factor IX (no alternate treatment & DDAVP useless as factor IX doesnt bind to cell walls)
what are coagulation factor inhibitors?
these are antibodies which develop to factor VIII and IX (very important in patients that regularly require recombinant factor VIII & IX)
what type of disease is von Willebrand’s disease?
autosomal dominant (NOT transmitted by the X chromosome) - therefor both sexes equally affected
what are the different types of von Willebrand’s disease?
Type One - dominant mild
Type Two - dominant mild
Type Three - recessive severe
why does insufficient clotting occur in von Willebrand’s patients?
defective vW factor on platelets which interacts badly with factor VIII so poor clot activation by platelets
how is severe & moderate von Willebrand’s disease managed?
DDAVP enough for most
how is mild von Willebrand’s disease / carriers of the disease managed?
mild cases may only require oral tranexamic acid
what is the most common inherited bleeding disorder in the UK?
von Willebrand’s disease
where are non-bleeding dental procedures carried out for a patient with a bleeding disorder?
- these can be done in primary care
in moderate/severe Haemophilia patients, where is majority of the treatment carried out?
the haemophilia centre (dental treatment uni)
what would an example of a ‘no-risk dental treatment’ be in relation to a patient with haemophilia?
prosthodontics care
when is SPECIAL CARE required for patients with haemophilia?
- administration of local anaesthetics (ID blocks***)
- extractions
- minor oral surgery
- periodontal surgery
- biopsies
in terms of local anaesthesia, what types are SAFE to do on patients with Haemophilia?
- buccal infiltration
- intraligamentary injections
- intra-papillary injections
what types of LA are considered DANGEROUS for patient suffering with HAemophilia?
- inferior alveolar nerve block
- lingual infiltration
- posterior superior nerve block
what is the post-operative treatment like for patients suffering from severe/moderate haemophilia when undergoing an extraction?
patients should be observed overnight following surgery
what post-operative care occurs for patients suffering with mild/carrier of haemophilia after a tooth extraction?
patients must be observed for 2-3 hours after surgery
what occurs in patients with Thrombophilia?
- increased risk of clots developing (clot formation ability greater than clot breakdown ability)
what are some thrombophilia inherited hypercoagulation syndromes?
- protein C deficiency
- protein S deficiency
- factor V Leiden
- Antithrombin III deficiency
how can Thrombophilia be acquired?
- oral contraceptives
- antiphospholipid syndrome
- surgery
- trauma
- cancer
- pregnancy
- immobilisation
what is the disorder called that causes reduced platelet numbers?
thrombocytopenia
what occurs in platelet qualitative disorders?
normal platelet number but abnormal function
