Signs and Symptoms of Pulmonary Embolism
The most common signs of pulmonary embolism include dyspnea (80% of cases), chest pain (52%), tachypnea (70%), tachycardia (26%), syncope (19%), cough (20%), and hemoptysis (11%). 1, 2, 3
Common Clinical Presentations
- Dyspnea is the most frequent symptom (80% of cases), which can be acute and severe in central PE or mild and transient in small peripheral PE 1, 3
- Chest pain is present in over half of cases and may be:
- Syncope or presyncope occurs in 19% of patients and is associated with more severe hemodynamic compromise 2, 3
- Hemoptysis is present in 11% of cases, resulting from alveolar hemorrhage caused by small distal emboli 2, 3
- Cough affects approximately 20% of patients 2, 3
- Tachypnea (respiratory rate >20/min) is present in 70% of cases 3
- Tachycardia (heart rate >100/min) is present in 26% of cases 3
- Signs of deep vein thrombosis (unilateral leg swelling, pain) are present in 15% of cases 3, 4
- Fever (>38.5°C) is present in 7% of cases 3
- Cyanosis is present in 11% of cases 3
- Hypotension and shock are hallmarks of central PE with severe hemodynamic consequences 1, 3
Presentation Based on PE Location
Central PE
- Often presents with acute and severe dyspnea 1, 3
- May present with substernal chest pain with anginal characteristics 1, 3
- Higher probability of hemodynamic instability 1
- More frequent syncope 2, 3
Peripheral PE
- Often presents with mild and sometimes transient dyspnea 1, 3
- May present with pleuritic chest pain 1, 3
- Associated with hemoptysis 2, 3
- May present with pleural effusion (usually mild) 3
Diagnostic Findings
Chest X-ray Findings
- Atelectasis or infiltrate (49% of cases) 3
- Pleural effusion (46% of cases) 3
- Pleural-based opacity/infarction (23% of cases) 3
- Elevated diaphragm (36% of cases) 3
- Decreased pulmonary vascularity (36% of cases) 3
- Amputation of hilar artery (36% of cases) 3
Laboratory and Other Findings
- Hypoxemia is present in 75% of cases, although up to 40% of patients may have normal arterial oxygen saturation 1, 2, 3
- Hypocapnia is often present due to tachypnea 2, 3
- Electrocardiographic changes may include:
Risk Stratification
PE severity can be classified based on risk of early mortality 1:
- High-risk PE: Characterized by hemodynamic instability (persistent hypotension, obstructive shock, or cardiac arrest) 1
- Intermediate-risk PE: Hemodynamically stable but with right ventricular dysfunction and/or myocardial injury 1
- Low-risk PE: Hemodynamically stable without signs of right ventricular dysfunction 1
Special Considerations and Clinical Pitfalls
- In patients with pre-existing heart failure or pulmonary disease, worsening dyspnea may be the only symptom indicative of PE 1, 3
- PE can be completely asymptomatic and discovered incidentally during diagnostic studies for other conditions 1, 3
- Approximately 40% of patients with PE do not have identifiable predisposing factors 1, 5
- Do not rule out PE based on normal oxygen saturation, as up to 40% of patients may have normal arterial oxygen saturation 1, 2, 3
- Do not dismiss transient symptoms, as they can lead to delayed diagnosis 3, 6
- PE continues to be underdiagnosed in emergency departments, which hinders appropriate treatment 6
- In approximately 25% of patients, the first manifestation of PE is sudden-unexpected death 6
Risk Factors
- Recent immobilization or major surgery 1, 5
- Recent lower limb trauma and/or surgery 1
- Clinical deep vein thrombosis 1, 5
- Previous proven DVT or PE 1, 5
- Pregnancy or post-partum period 1, 5
- Major medical illness 1
- Malignancy 5, 7
- Obesity 6
- Psychiatric disorders (noted in 31% of sudden death cases) 6
By recognizing these signs and symptoms early, clinicians can initiate appropriate diagnostic workup and treatment, potentially reducing morbidity and mortality associated with pulmonary embolism.