Pulmonary Embolism Flashcards
What are the two types of thromboembolic disease?
DVT
PE
What is a PE?
A blockage of a pulmonary artery by a blood clot, fat, tumour or air that can cause pulmonary infarction
What are the two different types of DVT?
Proximal (ileo-femoral) - most likely to embolise and lead to chronic venous leg ulcers
Distal (polpiteal) - least likely to embolise
What is the clinical presentation of a DVT?
Whole leg/calf involvement
Swollen, hot, red, tender calf
What is the differential diagnosis of a DVT?
Popliteal synovial rupture (baker’s cyst)
Superficial thrombophlebitis
Calf cellulitis
How can a DVT be diagnosed?
Ultrasound doppler legscan - excludes popliteal cyst or pelvic mass
CT scan - ileo-femoral veins, IVC and pelvis
What is the clinical presentation of a large pulmonary emboli?
CV shock, low BP, central cyanosis, sudden death
What is the clinical presentation of a medium pulmonary emboli?
Pleuritic pain, haemoptysis, breathlessness
What is the clinical presentation of a small recurrent pulmonary emboli?
Progressive dyspnoea, pulmonary hypertention, right heart failure
What are the risk factors for a DVT and PE?
Thrombophilia Contraceptive pill, HRT Pregnancy Pelvic obstruction (uterus, ovary, lymph nodes) Trauma (road traffic accident) Surgery (pelvis, hip, knee) Immobility (bed rest, long haul flights) Malignancy Obesity Pulmonary hypertension Vassculitis
How can a DVT be prevented?
Early post-op mobilisation TED compression socks Calf muscle exercises Subcutaneous low dose heparin pre-op Direct oral anticoagulant (dabigatran, apixaban)
What will the history of the presenting complaint be with a DVT?
Shortness of breath (acute onset) Chest pain (pleuritic) Haemoptysis Leg pain/swelling Collapse/sudden death
What are the clinical features of a PE?
Tachycardia, tachupnoea, cyanosis, fever, low BP, crackles, rub, pleural effusion
ABG: Low PaO2, Low SaO2
CXR: Basal atelectasis, consolodation, pleural effusion
What are investigations that can be carried out to diagnose a PE?
Pulmonary Embolism Severity Index (PESI) ECG: Acute right heart strain pattern D-dimers raised Troponin +/- V/Q scan - perfusion defect before infarction, perfusion and ventilation matched defect after infarction CTPA Leg and pelvic ultrasound for silent DVT Echocardiogram
What can cause a PE?
Surgery Pregnancy Malignancy Immobility Autoantibodies - anti-nuclear, anti-cardiolipin Thrombophilia screen
How is a low risk PE managed?
Low PESI, negative troponin, no oxygen and no co-morbidities
Ambulatory pathway then home
How is a high risk PE managed?
If CV compromise then thrombolysis may be needed
Monitor BP
HDU
How is a DVT/PE treated?
Anticoagulation prevents clot propagation
Therapeutic dose of heparin
Empirical treatment if high clinical suspicion whilst await conformation with investigations
LMWH once daily injection requires no monitoring
Start warfarin simulatenously
After 3-5 days stop heparin when INR > 2
Use DOACs - dabigatran, abpixaban
What is the target ranges of INR?
2,0-3,0 - 1st event
- 0 or more for recurrent events
- 5 if recurrent DVT/PE whilst on warfarin
What are some more invasive preventions/treatments of DVT/PE?
IVC filter to prevent embolisation from large ileofemoral/IVC clot
Thrombo-embolectomy
Intra-cathater directed thryombolysis
What is the duration of treatment of DVT?
Depends on the balance of risk between risk of repeat clot vs bleeding Unprovoked 1st PE: 6 months Provoked PE: 3 months Unprovoked low-risk distal DVT: 3 months Recurrent DVT/PE: life-long
What is pulmonary hypertension?
Pulmonary circulation is usually high -flow, low pressure system
Normal mean pulmonary arterial pressure (mPAP): 12-20 mmHg
mPAP > 25 = pulmonary hypertension (PH)
What can cause pulmonary hypertension?
Pulmonary venous hypertension (left heart disease): left ventricular systolic dysfuction, mitral regurgitation, cardiomyopathy
Primary pulmonary hypertenstion: hypoxia (COPD, OSA, pulmonary fibrosis)
Multiple PE
Vasculitis
Drugs
HIV
Cardiac left to right shunt
What is cor pulmonale?
Right heart failure secondary to lung disease
Fluid retention due to hypoxia
Can complicate COPD, fibrotic lung disease, chronic PE, chronic ventilatory failure (obesity, kyphoscoliosis)
What are the clinical signs of pulmonary hypertension/ RHF?
Central cyanosis Dependent oedema Raised JVP with V waves Right ventricular heave at left parasternal edge Murmur of tricurpid regurgitation Load P2 Enlarged liver
How is pulmonary hypertension investigated?
ECG - rhythm, axis, right bundle branch block CXR - cardiomegaly SaO2 and ABG Pulmonary function with DLCO (diffusion capacity) Echo Cardiac catheritisation to measure mPAP D dimer / VQ scan CTPA Cardiac MRI
How is chronic thromboembolic pulmonary hypertenstion treated?
Riociguat - pulmonary arterial vasodilator
Pulmonary endarterectomy
