Deep Vein Thrombosis and Pulmonary Embolus Flashcards
What is VTE?
Venous thrombo embolic disease
25,000 deaths/ye in UK
What is a thrombosis?
Intravascular solidification of blood constituents
What is an embolism?
Vascular obstruction at a site distant from the embolus origin
How common is DVT?
1 in 20 affected during lifetime
1 / 1000 people / yr
What is Virchaus Triad?
Alterations in blood flow
Alterations in blood constituents
Vascular endothelial injury
What are the 9 main acquired risk factors for VTE?
malignancy surgery trauma immobility obesity pregnancy HRT previous thrombo-embolism oral contraceptive pill
What are the 4 main inherited risk factors for VTE?
Factor V mutation
Prothrombin gene mutation
Protein ‘S’ or ‘C’ deficiency
Antithrombin III deficiency
How does DVT present?
Pain, tenderness, swellign, erythema, heat, venous engorgement
What are the differential diagnoses of DVT?
cellulitis, lymphoedema, muscle strain/tear, drug induced oedema, chronic venous insufficiency
How to investigate DVT?
D-dimer blood test
USS / Doppler
venogram
What is a D-dimer blood test?
method of investigating DVT. It looks at the products of thrombus fibrinolysis. Plasmin enzyme breaks down the fibrin mesh but it is unable to break the bonds between 1E and 2D units. The remaining protein fragment is a D-dimer
What are the problems with the D dimer test?
95% Sensitivity
50% Specificity
What are secondary results of DVT?
Venous insufficiency - hyper pigmentation, limb pain, swelling, dermatitis, ulcers, gangrene
Recurrent DVT
Pulmonary embolism
What is a pulmonary embolism (PE)?
Obstruction of a pulmonary artery or one of its branches (usually from DVT but can be from tumour or fat)
How does a PE present?
collapse pleuritic chest pain dyspnoea tachypnoea tachycardia
What is the treatment for a PE?
Uncomplicated PE - immediate anticoagulation with heparin
Major PE - systemic thrombolysis, catheter embolectomy with local thrombolysis, surgical embolectomy
Indications for thrombolysis?
Massive PE
Hypotension
Systemic hypo-perfusion
How can PE be prevented?
Calf pumping
LMWH
Early mobilisation
When should an IVC filter be used for PE treatment?
If PE with contraindication to anticoagulation or if recurrent PE despite adequate anticoagulation
What are NOACS?
Novel Oral Anticoagulants.
Developed because warfarin is awkward to use and cause a high degree of morbidity, mortality and cost.
They require minimal monitoring as can cause adverse effects through bleeding and interact with drugs which affect haemostasis
Name and describe 2 NOACS?
Dabigatran - direct thrombin inhibitor
Rivaroxaban and apixaban - direct factor Xa inhibitors
What are NOACS currently licensed for?
Prevention of VTE around surgery and being used as anticoagulation in atrial fibrillation
