Clinical Manifestations of Pulmonary Embolism
Most patients with PE present with breathlessness and/or tachypnea >20/min; in the absence of these findings, pleuritic chest pain or hemoptysis is usually due to another cause. 1
Cardinal Presenting Symptoms
The clinical presentation of PE varies dramatically based on thrombus burden and hemodynamic status:
Common Symptoms
- Sudden dyspnea - the most frequent presenting symptom 2
- Pleuritic chest pain - sharp, localized pain worsening with inspiration 1, 3
- Cough - often non-productive 3
- Hemoptysis - less common but highly suggestive when present 1
- Limb swelling - indicating concurrent deep vein thrombosis 2
- Syncope - suggests massive PE with hemodynamic compromise 2
Critical Physical Examination Findings
In the absence of all three findings—tachypnea (>20/min), pleuritic pain, and arterial hypoxemia—a diagnosis of PE can be excluded. 1
Key examination findings include:
- Tachypnea (respiratory rate >20/min) - present in most PE patients 1
- Tachycardia - common in moderate to severe PE 4
- Hypoxia - arterial oxygen desaturation 1
- Engorged neck veins - indicates right heart strain in massive PE 1
- Right ventricular gallop - often present in massive PE 1
- Hypotension/shock - defines high-risk PE requiring immediate reperfusion therapy 1, 3
Risk Stratification Based on Clinical Presentation
High-Risk (Massive) PE
Massive PE is highly likely if collapse/hypotension AND unexplained hypoxia AND engorged neck veins are present together. 1
These patients require:
- Immediate bedside transthoracic echocardiography to differentiate PE from other acute conditions and assess right ventricular dysfunction 1, 3
- Systemic thrombolysis as first-line treatment unless absolute contraindications exist 1, 4, 3
- Alteplase 50 mg IV bolus for cardiac arrest or rapidly deteriorating patients 1
- Alteplase 100 mg over 90 minutes for stable patients with confirmed massive PE 1, 4
Intermediate-Risk PE
Patients without hemodynamic instability but with evidence of right ventricular dysfunction or myocardial injury require:
- Further risk assessment involving clinical findings, RV size/function evaluation, and biomarkers 1
- Close monitoring with contingency planning for reperfusion if deterioration occurs 1
- Anticoagulation as primary treatment rather than immediate thrombolysis 1
Low-Risk PE
Patients who are not unduly breathless, without hemodynamic compromise, may be considered for:
- Outpatient treatment if no medical or social contraindications exist and efficient protocols are in place 1
- Early discharge after initial stabilization 1
Temporal and Anatomic Patterns
PE presentation varies by:
- Anatomic location - central emboli cause more severe hemodynamic compromise than peripheral emboli 2
- Bilateral versus unilateral - large bilateral emboli indicate higher risk 4
- Subsegmental emboli - may be asymptomatic or cause minimal symptoms, though clinical significance remains controversial 1
Common Pitfalls in Clinical Recognition
A critical caveat: PE is both overdiagnosed and underdiagnosed in clinical practice. 1
Key pitfalls to avoid:
- Young women on oral contraception with isolated pleuritic chest pain, respiratory rate <20/min, and normal chest radiograph are very unlikely to have PE 1
- Post-operative patients will have elevated D-dimer regardless of PE presence, making this test unreliable 5
- Elderly and comorbid patients are at higher risk but may present with atypical symptoms 2
- Subsegmental PE on CTPA may represent false-positive findings requiring radiologist discussion before committing to anticoagulation 1
Associated Risk Factors in Presentation Context
Predisposing factors are found in 80-90% of PE patients. 1
The most common include: