18. Haemostasis and Thrombosis Flashcards
What is haemostasis?
Arrest of blood loss from damaged vessels
What is thrombosis?
Pathological formation of a haemostatic plug within vasculature in absence of bleeding
What are the factors of Virchow?
Factors that predispose to thrombosis
- Injury to vessel wall
- Altered blood flow
- Abnormal coaguability
What defects can lead to haemostatic disorders?
Platelets too low or dysfunctional
Coagulation factors
Fibrinolytic system
What system is DIC a defect in?
Fibrinolytic
Where is it common to have venous thrombi?
Lower limb
Lungs
Where are less common sites for venous thrombi?
Upper limb Mesenteric veins Hepatic Cerebral Portal
What are the symptoms of a DVT?
Pain
Erythema
Swelling
What are the symptoms of a PE?
SOB
Tachycardia
Tachypnoea
Haemoptysis
What is the best choice of imaging to show a PE?
Pulmonary angiogram
How is a PE diagnosed?
History and exam
Ultrasound for lower limb, or pulmonary angiogram
Well’s score for PE
Why is a left sided DVT more common in pregnancy?
due to uterus position
How are DVTs treated in pregnant women?
Low Molecular Weight Heparin
When is the highest risk for pregnancy related DVT?
6 weeks post partum
Why is cancer high risk for DVT?
Tumour might cause obstruction to veins
Associated surgery
Prothrombotic signals from tumour cells
Central lines and chemotherapy
What score is used to assess the risk of DVT in cancer?
Khorana score
How is DVT treated in cancer patients?
6 months LMWH or DOACS
What are the diagnostic criteria for Antiphospholipid Antibody syndrome?
One of: Arterial/venous thrombosis 3 consecutive 1st trimester miscarriages Loss in 2nd or 3rd trimester AND positive test on 2 occasions 12 weeks apart
What are the treatment options for VT?
- LMWH (5 days) and warfarin
2. DOACs (may need LMWH lead-in)
How long does treatment last for provoked venous thrombosis?
3-6 months
How long does treatment last for unprovoked VT?
Longterm
What does DIC stand for?
Disseminated Intravascular Coagulation
What is DIC characterised by?
Presence of both thrombin and plasmin
How is DIC treated?
By treating the underlying cause
What are the lab results for DIC?
High prothrombin time and activated partial thromboplastin time
Low fibrinogen
high D-dimers
Low platelet count
