Pleuritic Chest Pain Flashcards
where is a thrombus (that leads to PE) usually formed?
systemic veins - pelvis and abdominal veins
rarely in right heart
what percentage of clinical PE’s are fatal?
10%
what causes clot formation?
combination of sluggish blood flow, local injury or compression of the vein and hypercoaguable state
what happens in the lungs following PE?
- lung tissue is ventilated but not perfused causing intrapulmonary dead space and impaired gas exchange and after some hours after non perfused lung it no longer produces surfactant
- alveolar collapse which exacerbated hypoxaemia
- reduction in cross sectional area of pulmonary arterial bed causing increased pulmonary arterial pressure and reduction in cardiac output
- the zone of lung no longer perfused by pulmonary artery may infarct but may not do so as oxygen continues to be supplied by bronchial circulation and airway
what are the clinical features of pulmonary embolism?
- sudden onset unexplained dyspnoea
- pleuritic chest pain and haemoptysis only happen when infarction has occured
- 3 typical clinical presentation (small/medium PE, massive PE, multiple recurrent PE)
where does a small/medium PE occur?
embolus impacted in terminal pulmonary vessels
What are the signs and symptoms of a small/medium PE?
- pleuritic chest pain and breathlessness, 30% have haemoptysis often >3 days after the initial event.
- On examination they may be tachypnoeic with localised pleural rub and course crackles.
- Exudative pleural effusion (often blood stained) can develop.
- May have a fever and cardiovascular examination normal
what are the CXR findings of a small/medium PE?
often normal
linear atelectasis or blunting of costophrenic angle may occur
these develop after time
may have raised hemidiaphragm
what are the ECG findings for a patient with small/medium PE?
usually normal except sinus bradycardia sometimes AF or another tachyarrythmia
evidence of right ventricular strain
what would blood tests in a patient with a small/medium PE show?
polymorphonuclear leucosytosis
elevated ESR
increased lactate dehydrogenase levels in serum
what is the role of D dimer in diagnosing small/medium PE?
if undetectable it rules out PE
what is the role of ultrasound scanning in diagnosing small/medium PE?
detect clots in pelvic or iliofemoral veins
what tests are used in diagnosis of small/medium PE?
- CXR
- ECG
- bloods
- D-dimer
- radionuclide ventilation/perfusion (V/Q scan)
- ultrasound
- CT
- MRI
what is a massive PE?
rarer condition
sudden collapse occurs because of an acute obstruction of the right ventricular outflow tract
-severe central chest pain
-shocked, pale and sweaty
-syncope if cardiac output is reduced and death may occur
what would be seen on examination in a patient with massive PE?
tachypnoeic
tachycardia with hypotension
peripheral shutdown
JVP raised with prominent a wave
what investigations would be used in a patient with massive PE?
- CXR
- ECG
- blood gases
- Echo
- pulmonary angiography
what would CXR show in a patient with massive PE?
may show pulmonary oligaemia sometimes with dilatation of pulmonary artery in hila
what would ECG show in a patient with massive PE?
right atrial dilatation with tall peaked P waves in lead II
Right ventricular strain and dilatation causes right axis deviation, degree of right bundle branch block and T wave inversion in right precordial leads
classic ECG patter with an S wave in lead I, and Q wave and inverted T waves in lead III is rare