Haematology - Bleeding Disorders Flashcards
What is primary haemostasis?
Platelet adhesion + aggregation
What is secondary haemostasis?
Coagulation cascade
What causes thrombosis disorders?
Defect in a part of Virchow’s triad
What are general symptoms of a patient with vascular defects or platelet disorders?
- Superficial bleeding into skin, mucosal membranes
- Bleeding imediately after injury
What are general symptoms of a patient with coagulation disorders?
- Bleeding into deep tissues, muscles, joints
- Delayed, but severe bleeding after injury
- Bleeding often prolonged
What are congenital and acquired causes of vascular defects?
Congenital:
- Osler-Weber-Rendu syndrome
- Connective tissue disease (e.g. Ehlers-Danlos Syndrome)
Acquired:
- Senile purpura
- Infection
- Steroids
- Scurvy
What are some acquired and congenital causes of decreased platelet function?
Acquired:
- Aspirin
- Cardiopulmonary bypass
- Uraemia
Congenital:
- Storage pool disease
- Thrombasthenia (glycoprotein deficiency
What are some causes of thrombocytopenia?
Decreased platelet production:
- Bone marrow failure
Increased platelet destruction:
- Autoimmune Thrombocytopenia Purpura (AITP/ITP)
- Drugs (e.g. heparin)
- DIC
- HUS
- TTP
What are some features and management of Acute ITP?
- Children 2-6yrs
- Male:Female = 1:1
- Precedes infection
- Symptom onset = abrupt
- Platelet count <20,000
- Lasts 2-6wks
- Spontaneous remission common, self-limiting
Tx:
- Steroids
- IVIG (if plts low)
What are some features + management of Chronic ITP?
- Adults
- Male:Female = 3:1
- No trigger (rarely precedes infection)
- Platelet count <50,000
- Long-term illness with acute flares (long-term relapsing-remitting)
Tx:
- IVIG
- Steroids
- Immune suppression
- TPO agonists
- Splenectomy
What is Factor V Leiden and its treatment?
Most common inherited prothrombotic disorder
- Resistance to Protein C results in failure to degrade Factor V leading to a hypercoagulable state
- Pre-disposes to VTE
- Tx: Long-term antioagulation
What is Haemophilia A, its inheritance, presentation and management?
- Factor VIII deficiency
- X-linked recessive
Presentation:
- Early in life
- Prolonged bleeding + haemarthrosis after surgery + trauma
Tx:
- AVOID: NSAIDs + IM injections
- Prophylaxis with Fx VIII in severe cases
What is Haemophilia B, its inheritance, presentation + management?
- Factor IX deficiency
- X-linked recessive
Presentation:
- Early in life
- Prolonged bleeding. haemarthrosis after surgery + trauma
Tx:
- Fx IX concentrates prophylactically or after bleeding
What is seen on clotting studies for haemophilia?
- Increased APTT
- Normal PT
- Decreased FVIII/FIX assay
- Normal plts
- Normal bleeding time
What are the different types of vWD and their inheritance pattern?
Type 1: (AD) Low levels of vWF - Quantitative defect
Type 2: (AD) Deficiency in function of vWF compared to level (mutations cause poor function) - Qualitative defect
Type 3: (AR) Absent vWF - Qualitative + Quantitative defect (can present like haemophilia)
What is the presentation and management of vWD?
Presentation:
- Bleeding indicative of platelet disorders
- ?Bleeding indicative of coagulation disorders
Tx:
- Prophylaxis in some pts
- Tx of bleeds = tranexamic acid, desmopressin + vWF + FVIII concentrates
What is seen on clotting studies for vWD?
- Increased APTT
- Normal PT/INR
- Decreased FVIII
- Decreased vWF Ag (or normal in type 2)
- Normal plts
Why is decreased FVIII seen in vWD?
vWF carries FVIII around in circulation
What is disseminated intravscular coagulation (DIC), its causes + treatment?
- Widespread activation of coagulation + fibrinolysis
- Clotting factors + platelets are consumed so causes increased risk of bleeding
Causes:
- Malignancy
- Sepsis (MOST COMMON)
- Trauma
- Obstetric complications
- Toxins
Tx:
- Treat cause
- Transfusions (coagulation Fx), FFP, Platelets, Cryo etc.
What is antithrombin deficiency, its mode of inheritance, diagnosis and management?
- VTEs develop in unusual locations (e.g. splenic/mesenteric veins)
- Autosomal dominant
Dx: Antithrombin assay
Tx: Long-term anticoagulation with warfarin + argatroban
What is seen in Liver Disease?
- Decreased synthesis of Fx II, V, VII, IX, X, XI + fibrinogen
- High levels of Fx VIII + vWF
- Decreased absorption of Vitamin K
- Abnormalities in platelet function
- Prolonged INR/APTT in chronic disease
What causes Vitamin K deficiency, what are some differential diagnoses + what is its treatment?
Causes:
- Warfarin
- Vitamin K malabsorption/malnutrition
- Abx therapy
- Biliary obstruction
DDx:
- Liver disease
- Scurvy
Tx:
- IV Vitamin K
- FFP for acute haemorrhage
What factors are reliant on vitamin K for their synthesis?
Factors II, VII, IX, X
+ Protein C/S
What is seen on clotting studies of Vitamin K deficiency?
- Normal plts
- Normal bleeding time
- Increased APTT
- Increased PT
