Clotting Disorders Flashcards
What is the role of the coagulation cascade?
Clots blood
What is the role of the plasminogen/ plasmin system?
Dissolves clots
What is the role of Factor XIII?
Stabilises fibrin clot
What impact does warfarin have?
Reduces coagulation factors
What impact does heparin have?
Acts to inhibit the coagulation cascade (similar action to antithrombin - a natural inhibitors)
What is the role of recombinant tissue plasminogen activator (rtPA)?
Increases plasmin activity
Name 4 blood tests which should be ordered for a bleeding patient.
- FBC with platelet count
- PT
- APTT
- Fibrinogen
How can you determine if the issue is due to a factor deficiency or the present of a coagulation factor inhibitor?
50/50 mixture study of patient/ normal plasma
If corrects = deficiency
If no correction = inhibitor
Which clotting factors affect APTT?
VIII, IX, XI, XII and von Willebrand factor
Which factor is implicated in Haemophilia A?
FVIII
Which factor is implicated in Haemophilia B?
FIX
List some basic principles in the treatment of haemophilia
- Treatment centre/ multidisciplinary
- . Treat early (if in doubt, treat)
- Fast Track triage in A&E
- Do not wait for clinical signs to develop
- Take care of veins
- Avoid drugs like aspirin
- Early home therapy
What does R.I.C.E stand for?
Rest, Immobilise, Cool, Elevate
In what form do factors VIII and IX come when treating haemophilia?
Recombinant
Describe the distribution of recombinant factor VIII
Large molecule so small distribution
How often does recombinant factor VIII need to be given?
Half life of 8 hours so once to three times daily
Describe the distribution of recombinant factor IX
Small molecule so large distribution
How often does recombinant factor IX need to be given?
Half life 18-25 hours so once daily
What is desmopressin (DDAVP) used for? And how does it work?
Haemophilia A only. It releases stored factor VII and so is useful for mild haemophiliacs. It raises VIII by 2 or 3 times. It should be tested with a trial of the drug since it has a variable effect. Can be given SC, IV or IN
What is transexamic acid used for? And how does it work?
Haemophilia A and B. It is an anti-fibrinolytic. It is given orally
What would prompt the progression from primary prophylactic treatment of haemophilia to secondary?
After 3 joint bleeds have occurred
What is the commonest coagulopathy?
Von Willebrand’s Disease
