Bleeding disorders Flashcards
What disorders are included in bleeding disorders?
Vascular defects (bruising)
Platelet disorders (low function)
Coagulation (factor def)
Mixed (DIC)
Which types of disorders present with immediate superficial bleeding after injury?
Platelet disorders
Vascular defects
Which types of disorders present with prolonged bleeding into deep tissues?
Coagulation disorders
Congenital vascular defect examples?
- Osler Weber Rendu syndrome
- Connective tissue disease e.g. ehlers danlos
Acquired examples of vascular defects?
- Senile purpura
- infection
- steroids
- scurvy
What can cause acquired decrease in platelet function?
Aspirin use
Cardiopulmonary bypass
Uraemia
What can cause congenital decrease in platelet function?
Storage pool disease
Thrombasthenia (glycoprotein deficiency)
What causes thrombocytopenia via decreased production?
Bone marrow failure (many disorders cause this)
What causes thrombocytopenia via destruction?
Auto-immune thrombocytopenic purpura (AITP / ITP)
Drugs : heparin, DIC, HUS, TTP
What is the common presentation of acute Immune thrombocytopenic pupura
Children 2-6
Abrupt onset preceding infection, lasts for 2-6 weeks and usually self limiting
What is the common presentation of chronic Immune thrombocytopenia?
Adult women, abrupt and indolent.
Long term with acute flares - autoimmune disease connection
Unlikely to resolve
What is the underlying deficiency in Haemophilia A?
Factor VIII deficiency
What is the inheritance pattern of Haemophilia A?
X-linked recessive (affecting 1 in 10,000 males)
How does Haemophilia A typically present?
Often early in life or as prolonged bleeding after surgery/trauma
What are the diagnostic tests for Haemophilia A?
↑ APTT
Normal PT
↓ Factor VIII assay
How is the severity of Haemophilia A classified?
Severe: Factor VIII <1%
Moderate: Factor VIII 1-5%
Mild: Factor VIII 5-25%
How is Haemophilia A managed?
- Avoid NSAIDs and IM injections
- Prophylaxis with factor VIII in severe cases
- Factor VIII treatment for bleeds in milder cases
Can Haemophilia A be acquired? If so, how is it treated?
Yes, it can be a rare autoimmune condition treated with immune suppression
What is the underlying deficiency in Haemophilia B?
Factor IX deficiency
What is the inheritance pattern of Haemophilia B?
X-linked recessive (affecting 1 in 50,000 males)
How does Haemophilia B present?
: Clinically similar to Haemophilia A
How is Haemophilia B managed?
Factor IX concentrates (either as prophylaxis or for bleeds)
What are the two broad types of Von Willebrand’s Disease (VWD)?
- Quantitative (deficiency of VWF)
- Qualitative (poor function of VWF)
What are the three types of Von Willebrand’s Disease?
- Type 1: Low levels of VWF
- Type 2: Deficiency in VWF function (mutations causing poor function)
- Type 3: Absent VWF – can present like haemophilia
How does Von Willebrand’s Disease affect coagulation factors and platelets?
↓ Platelet function
↓ Factor VIII (VWF carries factor VIII in circulation)
What is the inheritance pattern of Von Willebrand’s Disease?
Mostly autosomal (affecting 1 in 10,000)
How does Von Willebrand’s Disease typically present?
- Bleeding indicative of platelet disorders (e.g., mucocutaneous bleeding)
Can also include bleeding indicative of coagulation disorders
What are the key diagnostic findings in Von Willebrand’s Disease?
- APTT & INR: Can be normal, but APTT may be prolonged
- ↓ Factor VIII
- ↓ VWF antigen (VWF Ag) (or normal antigen with reduced function in type 2)
- Normal platelet count
- Abnormal Ristocetin co-factor assay
How is Von Willebrand’s Disease managed?
Prophylaxis in some patients
Treatment of bleeds:
- Tranexamic acid
- Desmopressin (induces release of VWF from Weibel-Palade bodies in endothelial cells)
- Combined VWF and Factor VIII concentrates
What is DIC?
Disseminated intravascular coagulation
- widespread activation of coagulation using up clotting factors and platelets causing a risk of bleed
What are the causes of DIC?
Cancer
Sepsis
Trauma
Obstetric complications
TOxins
What is the biochemistry of DIC?
Low plts, low fibrinogen, high FDP/D-Dimer, prolonged PT/INR
What does liver failure do to bleedingg?
↓ synthesis of II, V, VII, IX, X, XI and fibrinogen
- High levels of VIII / VWF
- absorption of vitamin K
- abnormalities of platelet function
- note that chronic liver disease is often a prothrombotic state despite having prolonged INR/APTT
What vitamin is needed for synthesis of factors 2, 7, 9 and 10?
Vitamin K
What causes vitamin K deficiency?
Warfarin, vitamin K malabsorption/malnutrition, Abx therapy, biliary obstruction
How to treat vitamin K deficiency?
IV vitamin K or FFP for acute haemorrhage
