Pulmonary Embolism Flashcards
define pulmonary embolism:
occlusion of pulmonary vessels, most commonly by a thrombus that has traveled to the pulmonary vascular system from another site.
what are the main causes of pulmonary embolism?
they are caused by thrombi
- 95% arise from DVT in the lower limbs
- in AF patients can arise in the right atrium.
what are other causes of embolus?
Amniotic fluid Air Fat Tumour Mycotic(infection of the arterial wall)
what are the risk factors for a pulmonary embolism?
Surgical patients Immobility Obesity OCP Heart failure Malignancy
what is the epidemiology of a pulmonary embolism?
- it is relatively common
- occurs in 10-20% of patients with a proximal DVT
what are the types of pulmonary embolism?
small
moderate
large
how might a small PE present?
might be asymptomatic
how might a moderate PE present?
- sudden onset SOB
- cough
- hemoptysis
- pleuritic chest pain
how might a large PE present?
- severe central pleuritic chest pain
- shock
- collapse
- acute right heart failure
- sudden death
when might one get multiple small recurrent PEs?
- pulmonary hypertension
what scorings can be used for PEs?
- PERC score to predict a PE
- Wells criteria to decide investigations for a PE
How to use the Wells score for PE?
- low probability 4 or less =
d-dimer - high probability higher than 4 = use imaging = CTPA
what other investigations should be carried out for a PE?
- Bloods - ABG and thrombophilia screen
- ECG
- CXR
- VQ scan
- pulmonary angiography
- doppler US of lower limb
- echocardiogram
what might an ECG show after a PE?
- May be normal
- May show tachycardia, right axis deviation or RBBB
- May show S1Q3T3 pattern
what might CXR show after a PE?
- often normal but might exclude other diagnoses
what might a CTPA show after a PE?
- poor sensitivity for small emboli
- high sensitivity for medium to large embolisms
what might a VQ scan show?
- Identifies areas of ventilation and perfusion mismatch
- this might show an area of the infarcted lung due to the PE
why are pulmonary angiograms not often used?
- they are invasive
why might a doppler US of the lower limb be used?
- allows assessment of venous thromboembolism
what might an echocardiogram show?
- right heart strain
How might a small PE show on physical examination?
- no signs
- may be tachycardia and tachypnoea
How might a moderate PE show on examination?
- Tachypnoea
- Tachycardia
- Pleural rub
- Low O2 saturation (especially after walking)
How might a severe PE show on examination?
- Shock
- Cyanosis
- Signs of right heart strain
what are signs of right heart strain?
- signs of pulmonary hypertension
- signs of right heart failure
what is the primary prevention for pulmonary embolism?
- compression stockings
- Heparin prophylaxis
- Good mobilization and adequate hydration
what is primary management for a hemodynamically stable PE patient?
- provide O2
- anticoagulation with heparin or LMWH
- then switch to warfarin for at least 3 months
- provide analgesia
what is primary management for a hemodynamically unstable PE patient?
- Resuscitate
- O2
- IV fluids
- thrombolysis if cardiac arrest is imminant
complications of a PE?
- Death
- Pulmonary infarction
- Pulmonary hypertension
- Right heart failure
the prognosis for pulmonary embolism?
- 30% mortality untreated
- 8% of mortality treated
- the increased future risk of thromboembolic disease
