Bleeding Disorders Flashcards
3 processes stopping bleeding
Vasoconstriction
Platelets plugging gaps
Coagulation cascade
Bleeding vasc defects
Osler-Weber-Rendu (hereditary haemorrhagic telangectasia)
Connective tissue disorders (e.g. Ehlers-Danlos)
Infection
Steroids
Scurvy
HSP
Bleeding platelet disorders
Aplastic/megaloblastic anaemia
Marrow infiltration/supression
Immune thrombocytopaenia and other autoimmune e.g. SLE, drug-induced, viruses
DIC, TTP, sequestration
Myeloproliferative disease, NSAIDs, increased urea all hinder platelet function
Bleeding coagulation disorders
Haemophilia, von Willebrand's Anticoagulants Liver disease DIC Vit K deficiency
What is Haemophilia A
X-linked recessive factor VIII gene inversion with high rate of new mutations (30% no family hx)
Haemophilia A presentation
After surgery/trauma, often early in life with bleeds into joints/muscles causing arthropathy + haematomas
Haemophilia A diagnosis
Increased APTT and decreased factor VIII assay
Haemophilia A management
Avoid NSAIDs + IM injections
Desmopressin 0.3mcg/kg/12h IVI over 20 mins for minor bleeds
Major bleeds recombinant factor VIII so levels are 50% of normal
Life threatening bleeds need 100% of normal
What is Haemophilia B (Christmas disease)
Inherited x-linked recessive factor IX deficiency behaves like haemophilia A
Treat with recombinant factor IX
What is acquired haemophilia
AutoAbs interfere with factor VIII, treat with steroids
Acquired haemophilia tests
Inc APTT
Factor VIII autoAbs
Factor VIII activity <50%
Bleeding disorder liver causes
Decreased synthesis of clotting factors
Decreased vit K absorption
Platelet function abnormalities
Treatment bleeding due to malabsorption
IV vitamin K (10mg) if that is deficient
In acute haemorrhage human prothrombin complex or FFP
Immune thrombocytopenia pathology
Anti-platelet autoAbs
Can be acute (2 wks self-limiting purpura usually in children) or chronic (fluctuating bleeding/ purpura/ epistaxis/ menorrhagia)
ITP tests
inc megakaryocytes in marrow
Anti-platelet Abs
ITP treatment
If mild, none
Prednisolone 1mg/kg/d, reduce after remission
No platelet transfusion as Abs destroy
If relapse, splenectomy or B-cell depletion with rituximab, Eltrombopag (oral thrombopoietin-receptor agonist) or Romiplostim (injectable thrombopoietin analogue)
Most common inherited thrombophilia
Activated protein C resistance (factor V Leiden)
Thrombophilia causes
Inherited:
Activated protein C resistance (factor V Leiden)
Prothrombin gene mutation
Protein C/S deficiency (vit K dependent factors)
Antithrombin deficiency
Acquired:
Anti-phospholipid syndrome
Oestrogens/pregnancy
Thrombocytosis/polycythaemia
Thrombophilia presentations
Arterial thrombosis/MI <50yrs
Unprovoked/recurrent VTE (/with pregnancy/contraceptives)
Neonatal thrombosis/ recurrent foetal loss
Unusual site e.g. mesenteric/portal vein
Thrombophilia management
Anticoagulate acute thrombus, only preventative anticoags if recurrent with no other RFs
Counsel on VTE RFs
Prophylaxis (heparin) in pregnancy/ pre-surgery
Disseminated intracvascular coagulation tests
Low platelets
Prolonged prothrombin time, APTT, and bleeding time
What is post-thrombotic syndrome
After DVT painful heavy calves, pruritis, swelling, varicose veins
Post-thrombotic syndrome treatment
Graduated compression stockings, only as treatment and not to be used as prophylaxis
von Willebrand’s disease treatment
Tranexamic acid for mild bleeding
Desmopressin induces vWF release from endothelial cells
Factor VIII concentrate
