DVT and Pulmonary Embolus Dr Piers Blombery BSc(Biomed), MBBS (Hons), FRACP, FRCPA Consultant Haematologist Peter MacCallum Cancer Centre
Overview Structure of deep and superficial venous system of upper and lower limb Venous thrombosis versus Arterial thrombosis Clinical features and consequences of DVT Clinical features and consequences of PE
Clinical case 56 year old woman with past history of hypertension and gout presents with iron deficiency anaemia Gastroscopy/Colonoscopy performed ulcerated lesion in sigmoid colon Biopsied colonic adenocarcinoma Undergoes anterior resection Very difficult venous access post-operatively due to previous IVDU required left femoral vein CVC placement for fluid/antibiotics, etc D4 post-operative complains of a sore and swollen left leg
The venous system - low pressure - variable anatomy - high capacitance - redundancy
UPPER LIMB VENOUS ANATOMY
LOWER LIMB VENOUS ANATOMY Superficial Deep
LOWER LIMB VENOUS ANATOMY Superficial Deep SUPERFICIAL FEMORAL VEIN
The arterial system - high pressure - constant anatomy - low capacitance - limited redundancy
Virchow s Triad
Venous thrombosis - Post-operative - Prolonged immobility (e.g. ICU) - Cast immobilisation - Prolonged plane flight
Venous thrombosis - Post-operative - Prolonged immobility (e.g. ICU) - Cast immobilisation - Prolonged plane flight - Cancer - Pregnancy/OCP - Antiphospholipid syndrome - Genetic predisposition
Venous thrombosis - Post-operative - Prolonged immobility (e.g. ICU) - Cast immobilisation - Prolonged plane flight - Intravenous Cannula - Trauma - Cancer - Pregnancy - Antiphospholipid syndrome - Genetic predisposition
Arterial Thrombosis Ligation of artery Atheroma with plaque rupture Genetic predisposition Anti-phospholipid syndrome
Some terminology Deep venous thrombosis/dvt a thrombosis occurring anywhere in the deep venous system Common parlance lower limb Pulmonary embolus occlusion of pulmonary arterial vasculature by any substance that has travelled from elsewhere Common parlance venous thromboembolism
Clinical features of lower limb DVT History Risk factors (immobilisation, Ca, FHx, etc) Swelling Calf pain Signs Lower limb erythema Lower limb pitting oedema Calf tenderness Venous gangrene (PCD)
Wells DVT score
Diagnosis of DVT Venous ultrasound of lower limb (or affected area)
Diagnosis of DVT Negative ultrasound doesn t rule out DVT Repeat in a week if clinically suspicious
Diagnosis of DVT Venogram not really performed in real life D-dimer Fibrinolysis product detectable in the circulation
Diagnosis of DVT D-dimer Highly sensitive Low specificity (any thrombosis, pregnancy, sepsis, infection, etc..) Pre-test probability is crucial
Prevention of DVT Prevent hypercoagulability Post operative anticoagulation Treat cancer Prevent endothelial injury Treat cancer Prevent stasis Early mobilisation TED stockings Sequential calf compression
Post-operative DVT chemoprevention NO ASPIRIN Two major options Low molecular weight heparin (enoxaparin, dalteparin) Oral Xa/Thrombin inhibitors (dabigatran, rivaroxaban, apixaban, edoxaban)
Consequences of DVT Pulmonary embolus Embolus elsewhere Recurrent DVT Post-thrombotic syndrome (~50%) Chronic leg/arm swelling Chronic pain, aching, tingling, heaviness Venous insufficiency Venous Ulceration
Consequences of DVT Post thrombotic syndrome caused by Residual thrombus leading to venous hypertension Destruction of wall of vein and valves by thrombus induced activation of inflammation and scarring
Treatment Prevention Anticoagulation Duration controversial and is highly dependent on provoking cause
Clinical case 17 year old female presents with 1/7 history of suddenonset shortness of breath and right-sided chest pain. Denies any regular medications On examination SaO2 91% on RA, PR 130 sinus tachycardia, BP 110/70, lungs clear, abdomen soft, no lower limb swelling
Pulmonary Embolus clinical features Signs Tachycardia, hypoxia Hypotension Signs of DVT Pleural Rub Symptoms Shortness of breath Pleuritic chest pain Central chest pain Syncope
Pulmonary Embolus Investigations CTPA or V/Q scan ECG (S I Q III T III, sinus tachycardia) Arterial blood gases (hypoxia, hypocapnia, respiratory alkalosis) D-dimer
Pulmonary Embolus V/Q CTPA Other causes of hypoxia/chest pain Sensitive Specific Avoids intravenous contrast
Wells PE score
Pulmonary Embolus - consequences Acute Death Cardiovascular collapse Hypoxia Pulmonary infarction Chronic Pulmonary hypertension Right sided heart failure Chronic hypoxia
Summary Venous thrombosis and arterial thrombosis are different pathologically and clinically DVT in the leg followed by embolus to the lung is the most common but not the only manifestation of VTE Virchows triad crucial for understanding causes and preventative measures for DVT / PE No test is perfect for ruling in or out DVT/PE Significant morbidity / mortality from DVT/PE means it is important regardless of your chosen specialty