Bleeding Disorders Flashcards
Describe disseminated intravascular coagulation and its causes
It is an acquired disease which causes microthrombi due to activation of the coag cascade and bleeding due to exhaustion of the coag cascade.
Caused by sepsis, malignancy, massive haemorrhage, severe trauma and pregnancy complications (pre-eclampsia, placental abruption, amniotic fluid embolism).
What are the laboratory investigations for DIC?
- Coagulation PT, APTT, Fibrinogen
- D-dimer
- FBC, Platelets and blood film which shows RBC fragments (Due to fibrin which lays down in the vessel and cuts the RBCs as they travel past)
What is the treatment for DIC?
Fresh frozen plasma +/- platelets if bleeding/high risk for bleeding.
How do you treat a major bleed for a patient in warfarin
- Stop warfarin,
- Give 5mg IV vitamin K,
- intravenous factor concentrate (prothrombin complex concentrate)
What can you do if there is a prolonged APTT?
50:50 dilution. mix patient plasma with normal plasma. If the patient has a factor deficiency then there will be full correction. If the patient has an inhibitor then there will only be partial correction
What is lupus anticogulant?
Phospholipid dependant antibody which interferes with phospholipid dependant tests eg, APTT. If it persists then it may be associated with a prothrombotic state
How can you test for lupus anticoagulant?
- APTT is often prolonged and only partially corrected with an APTT 50:50 dilution.
- DRVVT ration prolonged and it corrected with excess phospholipids
Explain acquired thrombophilia
- It is an antiphospholipid syndrome caused by the presence of antiphospholipid antibodies. This could be lupus anticoagulant, anti cardiolipin antibodies or beta-2 glycoprotein-1 antibodies.
They disrupt annexin V sheild which expose excess phospholipid. Can cause venous/arterial thrombosis or recurrent miscarriages.
Describe features of haemophilia A
- An x-linked deficiency of factor VIII.
- Results in prolonged APTT
What is the treatment for coagulation factor deficiencies
- Education,
- Desmopressin (increases endogenous release of factor 8)
- Replacement therapy (FFP, plasma derived factor concentrate and recombinant produced factor concentrate)
What is the role of Von Williebrand factor?
- Facilitates platelet adhesion and aggregation in primary haemostasis,
2.Binds to factor VIII and prolongs its half life in plasma
Describe features of Von Williebrand disease
- Autosomal dominant condition with variable penetrance.
- Leads to muscosal type bleeding patteern
- Will cause reduced VWF, and possibly reduced platelet aggregation and reduced factor VIII
What are the different classes of Von Williebrand disease?
Type 1 - Partial quantitative deficiency
Type 2 - Functional deficiency
Type 3 - Almost complete deficiency of VWF
Name some different severe inherited platelet disorders
- Glansmanns Thrombasthenia (normal platelet count bit absent/defective GP IIb/IIIa)
-Bernard Soulier Syndrome (Absent/defective GP Ib/V/IX and macrothrombocytopenia) - Both are rare autosomal recessive disorders with mucosal type bleeding pattern
Inherited platelet disorders are BullShit and Great Threats
How can you treat bleeding in a person with an inherited platelet disorder?
- Pressure to wounds
- Tranexamic acid/desmopressin
- Platelet transfusion
- Recombinant factor VIIa
