Untitled Deck Flashcards
What are the main antifibrinolytic agents used in coagulation support?
Tranexamic acid.
How is warfarin reversal achieved?
With vitamin K or Octaplex (factors II, VII, IX, X).
What is used in patients with inhibitors during bleeding?
Factor VIIa or increased doses of factor VIII to overpower antibodies. FEIBA or Octaplex can also be used.
What is disseminated intravascular coagulation (DIC)?
An acquired thrombophilia where widespread clotting and bleeding occur.
Why do many elderly patients not switch from warfarin to DOACs?
Warfarin is cheaper but requires complex management, whereas DOACs are simpler but more expensive.
What is haemarthrosis?
Bleeding into joints, often seen in untreated haemophiliacs, leading to joint fixation.
How much factor level is required to maintain hemostasis?
At least 25% of factor levels, but up to 100% is targeted before surgery to reduce transfusion needs.
What is desmopressin (DDAVP) and how does it work?
Desmopressin increases von Willebrand factor (vWF) and factor VIII levels by 2-6 times. It is cheap, safe, and widely available.
What is the half-life of desmopressin (DDAVP) and its implication in surgery?
12 hours. If surgery is delayed beyond 24 hours, factor levels return to baseline.
What is the role of tranexamic acid in coagulation?
It is an antifibrinolytic that prevents clot breakdown by inhibiting the conversion of plasminogen to plasmin.
How are patients with von Willebrand disease (vWD) treated?
Type 1: Desmopressin or tranexamic acid mouthwash.
Type 2: Treated with vWF concentrates like Willate.
Type 3: Requires vWF concentrates; DDAVP is ineffective.
What is the preferred method for managing warfarin reversal in severe cases (INR > 20)?
Octaplex is preferred over plasma to avoid adding fuel to the fire.
What factors are included in Octaplex?
Factors II, VII, IX, X, as well as proteins C and S.
Why is Hepatitis B considered particularly resilient?
It is highly durable and survives in various conditions.
What led to significant HIV and Hepatitis C transmission in haemophiliacs in the past?
Contaminated plasma-derived products before the advent of viral inactivation methods.
How are plasma-derived products inactivated to ensure safety?
Through methods such as solvent detergent treatment, dry heat, and pasteurization.
What is the Ristocetin cofactor assay used for?
To test if vWF is effectively binding platelets.
How is cryoprecipitate discovered and what does it contain?
Discovered accidentally; it contains fibrinogen, vWF, and factor VIII.
What are the advantages of recombinant factors over plasma-derived products?
Recombinant factors are safer, with no risk of viral transmission, although human-derived products are cheaper.
What is the role of FEIBA in haemophilia management?
It is used to bypass inhibitors by providing activated clotting factors.
How is tranexamic acid used in dental procedures for coagulation disorders?
It can be applied as a mouthwash every 6 hours or incorporated into tissue packs to control bleeding.
What makes vWF a ‘sticky’ protein?
It binds platelets and factor VIII, playing a key role in clot formation.
Why are human-derived products still used in some countries?
They are cheaper, although they are now viral-inactivated to ensure safety.
What cells are used to produce recombinant factor VIII?
Chinese hamster ovary cells, as they allow proper glycosylation required for function.
What is the treatment of choice for haemophiliacs with intracranial hemorrhage?
Rapid infusion of factor concentrates to restore adequate clotting factor levels.
What is the role of monoclonal antibody columns in coagulation product preparation?
They are used to purify specific clotting factors, such as factor VIII, enhancing product safety and efficacy.
Why is factor VIII often administered with von Willebrand factor (vWF)?
vWF stabilizes factor VIII in circulation, enhancing its half-life and efficacy in preventing bleeds.
What is the effect of prosthetic joints on haemophilia treatment?
Prosthetic joints can improve mobility for haemophiliacs with chronic joint damage caused by repeated bleeds.
What is the primary cause of haemarthrosis in children with haemophilia?
Repeated bleeding into joints due to low clotting factor levels.
What happens if surgery for a haemophiliac is delayed beyond 24 hours?
Factor levels, increased by treatments like DDAVP, return to baseline, necessitating repeated dosing.
How is haemophilia treatment different for ‘low responders’ with inhibitors?
Increased doses of factor VIII can be used to overpower antibodies, or alternative agents like FEIBA are employed.
What is the primary advantage of recombinant products over plasma-derived products?
They eliminate the risk of viral contamination.
What is the impact of delayed recognition of moderate haemophilia?
Patients may only be diagnosed during events like dental extractions, leading to unanticipated bleeding complications.
Why is octaplex used in Ireland for coagulation support?
It is a cost-effective option that provides multiple clotting factors along with proteins C and S.
How do antifibrinolytics support haemostasis?
By preventing the breakdown of clots, thus stabilizing formed thrombi in bleeding patients.
