Pulmonary Emboli and Pulmonary Hypertension Flashcards
Why don’t pulmonary pressure increase with increased cardiac output, for example, during exercise?
Dilatation and recruitment of pulmonary vessels
What are the causes of pulmonary hypertension?
Increased left atrial pressure
Increased pulmonary blood flow
Increased pulmonary vascular resistance
What are some causes of increased left atrial pressure?
Mitral stenosis
Left ventricular dysfunction
Diastolic dysfunction
What are some causes of increased pulmonary blood flow?
Left to right shunts
High flow states
Excess central volume
What are the causes of increased pulmonary vascular resistance?
Vasoconstriction - Low alveolar O2 Obstruction - Embolism - Primary pulmonary hypertension Obliteration - Arteritis - Emphysema - Pulmonary fibrosis
What is the mechanism of right ventricular failure?
Pulmonary hypertension (PA pressure >25 mmHg) > right ventricular dilatation and hypertrophy >
- Increased systemic venous pressure > extravasation of fluid into tissues and peritoneal/pleural space
- Poor cardiac output > gas exchange reduced > hypoxaemia, particularly with exertion
What are the symptoms of pulmonary vascular disease?
Shortness of breath - Sudden - Gradual onset Syncope/collapse Lassitude Swelling of ankles Cough Chest pain, often pleuritic Haemoptysis
What are the signs of pulmonary vascular disease?
Signs of pulmonary hypertension - Right ventricular heave - Loud P2, 4th heart sound - Prominent V wave in JVP Sings of right heart failure - Elevated JVP +/- v waves - Tricuspid regurgitation - Ascites - Pulsatile liver Signs of cause
Where do pulmonary emboli come from?
Most commonly detach from deep vein thrombosis in leg
Fat; eg: post trauma
Air; eg: post laproscopic surgery
Amniotic fluid
What is the pathogenesis of thrombosis?
Stasis - Inpatient - After some surgical procedures - Prolonged immobility Hypercoagulable state - Genetic abnormalities; eg: factor deficiencies - Malignancy - Polycythaemia - Pregnancy - Medication Abnormal vessels; eg: post trauma
What are the clinical features of pulmonary embolism?
Need to have high level of suspicion in certain clinical situations Collapse and hypoxaemia Widened Aa gradient of unclear cause Pleuritic chest pain of unclear cause Unexplained breathlessness Evidence of pulmonary hypertension of unclear cause Risk factors Evidence of DVT - Calf pain - Calf swelling Medium clot burden - Dyspnoea - Pleuritic chest pain - Cough - Haemoptysis - Fever Examination - Tachypnoea - Tachycardia - Pleural rub/effusion
What is Wells criteria?
Clinical assessment of pulmonary embolism
What are the investigations for pulmonary embolism?
D-dimer Troponin ECG Ventilation/perfusion (VQ) scan CTPA
Describe the D-dimer test
Fibrin degradation product
Good sensitivity
Not specific
Negative predictive value excellent with low clinical probability of PE
Describe measuring troponin in the diagnosis of pulmonary embolism
Elevated in 30-50% of large PEs
Not sensitive nor specific
Can be marker of prognosis
Describe using an ECG in the diagnosis of pulmonary embolism
Abnormal in up to 70% of patients
Not specific
Describe the use of a VQ scan in the diagnosis of pulmonary embolism
Combine with clinical probability
- High clinical and high probability VQ = 95% likelihood of having PE
Normal scan virtually rules out PE
Many patients fall into intermediate group so further tests often needed
Describe the use of a CTPA in the diagnosis of pulmonary embolism
Diagnostic test of choice
May detect other pulmonary abnormalities
Low risk of PE if negative
Combine with clinical probability
What are other, less common, investigations for diagnosing pulmonary embolism?
Echocardiogram - Abnormalities present in 30-40% of PE cases - May be useful in massive PE Venous ultrasound - Not routine - May be helpful Pulmonary angiography - Gold standard - Rarely done
What is the treatment of PE?
Respiratory support Haemodynamic support Thrombolytic therapy - Reduces some complications - Reserved for most severe cases Inferior vena cava (IVC) filter - If failure of/contraindication to anticoagulation/further PE might be lethal Anticoagulation - ASAP - Heparins - Warfarin for longer-term use (3-6 months standard)
What are some newer agents available for anticoagulation in the treatment of pulmonary embolism?
Rivaroxiban
Apixaban
Dabigatran
What are the investigations required for COPD with right heart failure (cor pulmonale)?
Basic bloods - FBE - U&Es - LFTs Arterial blood gases CXR Lung function ?Sleep study Echocardiogram
What is the management for COPD with evidence of right heart failure?
Cease smoking Oxygen Pulmonary rehab Bronchodilator therapy Diuretics
What are the diagnostic classifications for pulmonary hypertension?
Pulmonary arterial hypertension
Pulmonary hypertension with left heart disease
Pulmonary hypertension with chronic lung disease/hypoxaemia
Pulmonary hypertension due to chronic thrombotic and/or embolic disease
Miscellaneous
What are the possible causes of pulmonary arterial hypertension?
Idiopathic Familial Related to - Connective tissue diseases - HIV - Portal hypertension - Anorexigens - Congenital heart diseases Persistent pulmonary hypertension of the newborn Pulmonary arterial hypertension with venule/capillary involvement
What are the possible causes of pulmonary hypertension with left heart disease?
Atrial/ventricular
Valvular
What are the possible causes of pulmonary hypertension with chronic lung disease or hypoxaemia?
COPD
Interstitial lung diseases
Sleep-disordered breathing
Developmental abnormalities
What are the possible causes of pulmonary hypertension due to chronic thrombotic and/or embolic disease?
Thromboembolic obstruction of proximal pulmonary artery
Thromboembolic obstruction of distal pulmonary artery
Non-thrombotic pulmonary embolism
What are the possible causes of miscellaneous pulmonary hypertension?
Sarcoidosis
What is the prognosis for pulmonary hypertension if left untreated?
Very poor prognosis
