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
what would blood gases show in a patient with massive PE?
arterial hypoxaemia with low arterial CO2 level (type 1 respiratory failure)
what would echo show in patients with massive PE?
vigorously contracting left ventricle and occasionally a dilated right ventricle and a clot in the right ventricular outflow tract
what is the role of pulmonary angiography in diagnosis of massive PE?
replaced by CT and MR angiography
what are the symptoms of multiple recurrent PE?
increased breathlessness often over weeks or months
accompanied by weakness, syncope on exertion and occasional angina
what are the signs of multiple recurrent PE?
due to pulmonary hypertension that has developed from multiple occlusions of pulmonary vasculature
signs of right ventricular overload with right ventricular heave and loud pulmonary second sound
what investigations would be needed in a patient with multiple recurrent PE?
- CXR
- ECG
- leg imaging
- V/Q scan
- multidetector CT scans
what would CXR show in a patient with multiple recurrent PE?
may be normal
enlarged pulmonary arterioles with oligaemic lung fields indicates advanced disease
what would ECG show in a patient with multiple recurrent PE?
can be normal or show signs of pulmonary hypertension
what would leg imaging show in a patient with multiple recurrent PE?
may show the thrombi
what are the risk factors for venous thromboembolism?
- cancer
- > 60 years
- critical care admission
- dehydration
- known thrombophilias
- obesity
- comorbidities
- family history
- hormone replacement
- varicose veins with phlebitis
- pregnancy/childbirth
what is a deep vein thrombosis?
thrombus forms in vein and inflammation of vein wall is secondary to this
usually occurs after immobilisation
often occurs in calf and often undetectable
what are the clinical features of DVT?
- aysymptomatic or with features of PE
- pain in calf
- swelling, redness, engorged superficial veins
- warmer, ankle oedema
- Homans sign (pain in calf on dorsiflexion)
- complete occlusion-cyanotic discoloration with severe oedema and venous gangrene
- can lead to PE
what investigations should be performed in patients with suspected DVT?
- D-dimer (80% sensitivity)
- Bmode venous compression
- ultrasonography
- doppler ultrasound
- below knee thrombus-only detected reliably by venography with non invasive techniques, ultrasound, fibrinogen scanning and impedance plethysmography
- venogram performed by injecting vein with contract
why may a diagnosis of PE be delayed?
signs and symptoms of small and medium sized PE often more subtle and nonspecific
when should a diagnosis of PE be considered?
if patient presents with symptoms of unexplained cough, chest pain, haemoptysis, new onset AF or signs of pulmonary hypertension if no other cause can be found
patients that are haemodynamically stable should have their clinical probability of a pulmonary embolus determined by geneva score
what investigations are performed for a patient determined to be
- at high risk of PE
- at low risk of PE
- multi detector contrast enhanced CT angiography
2. D dimer
what factors would give a score of 1 on the geneva score for PE?
Age >65
what would give a score of 2 on the geneva score for PE?
- surgery or fracture within 1 month
- active malignancy
- haemoptysis
what would give a score of 3 on the geneva score for PE?
- previous DVT or PE
- unilateral leg pain
- HR of 75-94
what would give a score of 4 on the geneva score for PE?
pain on leg DVT and unilateral oedema
what would give a score of 5 on the geneva score for PE?
HR >95
what is the clinical probability of PE based on the geneva score
low= 0-3
intermediate=4-10
high=>11
what makes up the acute management of PE?
- high flow oxygen (60-100%)
- bed rest + analgesia
- IV fluids
- fibrinolytic theraoy
- surgical embolectomy
what anticoagulation should be given to manage acute PE?
subcutaneous LMWH or fondaparinux or IV unfractionated heparin followed by warfarin
how can further emboli be prevented?
- vitamin K antagonist 3-6 months (INR 2-3)
- cancer patients/pregnant women should be given long term LMWH
describe the treatment of DVT?
- prevent PE
- anticoagulate (below knee for 6 weeks)
- bed rest (elastic stocking)
- LMWH
- thrombolytic therapy
what is the prognosis for DVT?
destruction of DVT can lead to the need for elastic support stockings for life
what measures can be take to prevent DVT?
- hospital admissions-at risk if reduced mobility for > 3days, surgical procedure >90 mins, acute inflammation, >1 risk factor
- pharmacological prophylaxis (fondaparinux or LMWH) unless risk for bleeding outweighs benefits
- mobilise, stockings
- on discharge give information about signs and symptoms of VTE
