1) Pulmonary embolism refers to obstruction of a pulmonary artery, most commonly by a thrombus originating from the legs or pelvis. 2) Risk factors include conditions contributing to Virchow's triad of venous stasis, hypercoagulability, and endothelial injury. 3) Presentation includes dyspnea, chest pain, cough, hemoptysis, and leg swelling or pain. Investigations include D-dimer, chest imaging, ventilation-perfusion scan, and pulmonary angiogram. Management focuses on oxygenation, fluid resuscitation, and anticoagulation.

1. Rawan Alsulmi
PULMONARY EMBOLISM

2. • Relevant anatomy
• Definition
• Risk Factors
• Pathology
• Clinical features
• Investigation
• Deferential Diagnosis
• Management
CONTENT

3. The lungs are supplied
with deoxygenated
blood by the
paired pulmonary
arteries.
Once the blood has
received oxygenation, it
leaves the lungs via four
pulmonary veins .
RELEVANT ANATOMY

4. WHAT IS PE?
A pulmonary embolism refers to the obstruction of a
pulmonary artery.
The most common emboli are:
Thrombus – responsible for the majority of cases and
usually arises from ilio-femoral veins or pelvic veins.
Fat – following a bone fracture or orthopaedic surgery.
Air – following cannulation in the neck.
Amniotic fluid.

5. RISK FACTORS:
“VIRCHOW’S TRIAD”

7. A massive embolism obstructs the right ventricular outflow tract and therefore
suddenly increases pulmonary vascular resistance, causing acute right heart failure.
A small embolus impacts in a terminal, peripheral pulmonary vessel and may be
clinically silent unless it causes pulmonary infarction. Lung tissue is ventilated but not
perfused, resulting in impaired gas exchange.
PATHOLOGY

8. CLINICAL FEATURES
• Dyspnea
• Tachypnea
• Pleuritic chest pain
• Fever
• Unilaterally swollen and painful posterior lower
extremity,
• Cough, Hemoptysis
• Patient prefers to lie flat, dyspnoea improves due to
increased venous return and right heart loading.

9. INVESTIGATIONS
Lab:
- ABG
Low PaO2, low or high PaCO2, and a metabolic acidosis.
- D-dimers
Sensitivity = 95-98%
A normal value probably excludes a pulmonary embolus

10. INVESTIGATIONS
Imaging :
1- X-ray:
• Fewer vascular markings (pulmonary oligaemia)
• Hampton’s hump sign
Wedge-shaped infarct
• Westmark’s sign
Hyperlucency in the lung region supplied by the affected
artery

12. CONT.…
2- ECG:
Sinus tachycardia
S1Q3T3—S wave in lead I, Q wave in lead III, and inverted T
wave in lead III , tachycardia, right axis deviation, right
bundle branch block, P pulmonale.
3- Echocardiogram: may reveal evidence of pulmonary
hypertension and acute right ventricular strain.

14. CONT..
4- Ventilation-perfusion scan:
Sensitivity = 98%; specificity = 40%
5- Pulmonary angiography:
is the Diagnostic test of choice

16. DDX
Condition Differentiating signs/symptoms
MI Retrosternal pressure radiating to the jaw, arm, or neck.
Risk factors include long-standing hypertension, diabetes, or
hypercholesterolaemia.
Pneumonia Cough, purulent sputum.
Fever above 39.0°C generally higher than in PE.
Pneumothorax History of recent trauma to the chest.
Decreased breath sounds unilaterally
Hyperresonance on percussion of affected side.
Deviation of the trachea away from the affected lung.
CHF, acute exacerbation Orthopnoea, paroxysmal nocturnal dyspnoea,
Increased bilateral lower extremity swelling.
Diffuse crackles on pulmonary auscultation.
Elevated jugular venous pressure.
Pericarditis Chest pain improves when sitting up and worsens when supine.
Tamponade, cardiac Beck's triad of hypotension, muffled heart sounds, and elevated
jugular venous pressure
Panic disorder Sudden-onset anxiety, feeling faint, and palpitations.
Recurrent, discrete period of intense fear/discomfort.

17. MANAGEMENT
General management
• FIO2 0.6–1.0 to maintain SaO2 93–98%.
• Lie patient flat to increase venous return.
• Fluid challenge to optimize right heart filling.
• Epinephrine infusion if circulation still
compromised.
• Mechanical ventilation may be needed. Gas
exchange may worsen due to loss of preferential
shunting and decreases in cardiac output.

20. PULMONARY EMBOLISM IN
PREGNANCY
Ultrasonography of the legs is the
initial investigation.
CTPA is required if ultrasound is
normal
Warfarin is teratogenic and confirmed
PE is treated with LMWH.

21. REVERENCES
Oxford critical care
BMJ
Kumar and Clark’s clinical medicine

22. THANK YOU