Lecture 6 - Clinical Considerations in VTE Flashcards
What is VTE?
Undesirable blood clotting in the venous system
Define Deep Vein Thrombosis (DVT)
Usually deep vein in the leg
When fragments of a clot break away, enter arterial circle elation form a secondary embolus elsewhere such as?
Pulmonary Artery - Pulmonary Embolism
Cerebral Artery - Stroke/ Transient Ischaemic Attack (TIA)
What are the symptoms of VT?
Usually unilateral
Swollen, tender leg
Heavy ache in the affected areas
Warm erythematous (red) skin
Pitting oedema
Prominent superficial veins
What level WELLS SCORE is likely of DVT?
more than 2 DVT likely
less than 2 DVT unlikely
Symptoms of PE
May be symptomless
Concurrent DVT
Breathlessness
Cough - dry/ blood stained (haemoptysis)
Pleuritic chest pain/ upper back pain
Tachycardia (fast heart rate)
Tachypnoea (fast respiratory rate)
Hypotension
Syncope (fainting)
Hypoxia/ cyanosis (turning blue)
What WELLS SCORE is likely of PE?
more than 4 PE likely
less than 4 PE unlikely
What are the investigations for VTE?
D-dimer
Venous Ultrasound ‘Doppier Scan’
CT Pulmonary Angiography (CTPA)
Ventilation Perfusion (VQ) Scan
Define d-dimer
By-product formed when thrombus (such as that found in DVT or PE) is degraded naturally by the body
Positive levels in the blood suggest DVT/PE
Define Ventilation Perfusion (VQ) Scan
Uses radiopharmaceutical material to visualise the lungs, useful in confirming PE
Define Venous Ultrasound ‘Doppier Scan’
An imaging technique used to visualise venous blood clots in situ
Useful in confirming DVT
Define CT Pulmonary Angiography (CTPA)
An imaging technique used to visualise thrombus in the pulmonary arteries
Useful in confirming PE
What are the bleeding risk factors?
Surgery related - neurosurgery, spinal and eye
Lumbar puncture, epidural, spinal anaesthesia
Medical conditions - recent stroke, impaired liver function, bleeding disorders, hypertension, thrombocytopenia (low platelets)
Medicine - anti-coagulants
What are the clotting risk factors?
Stagnation of blood - not mobile
Vascular injury - surgery, broken bones, vasculitis, varicose veins
Medical conditions - pregnancy, clotting disorders, previous/family history, some cancers and chemotherapies, CV or lung disease, inflammatory disease, COVID-19
Others - age >60, overweight, smoking, oestrogens (HRT/COC), dehydration
When should patients have a VTE Risk assessment?
Hospitalised patients should have their clotting vs bleeding risk assessed on admission to the hospital and after every change in clinical condition
If clotting risk>bleeding risk need VTE prophylaxis with an anti-coagulant to prevent VTE from developing
Examples of Low Molecular Weight Heparin (LMWH)
Dalteparin, enoxaparin, tinzaparin
Given by sc fixed dose injections on the basis of body weight
Predominately really excreted
What can be taken when bleeding occurs on a LMWH?
Antidote - protamine (partial reversal only)
What are the main uses of LMWH?
VTE prophylaxis
Treatment of confined VTE - prevents enlargement of clots, enabling clot breakdown by the body own homeostatic mechanisms
Anti-coagulant ‘bridging’