Patient with History of PE Presenting with One Week of Cough
Pulmonary embolism should be considered in this patient, but the one-week duration of cough makes recurrent PE less likely than other respiratory causes such as lower respiratory tract infection, exacerbation of underlying lung disease, or pleural complications from the prior PE. 1
Initial Risk Stratification for Recurrent PE
The clinical probability of recurrent PE must be assessed first using validated criteria:
- PE is highly unlikely if ALL of the following are present: age <50 years, heart rate <100/min, oxygen saturation >94%, no recent surgery or trauma, no hemoptysis, no unilateral leg swelling, and no estrogen use 2
- PE should be considered if ANY of these risk factors exist: history of DVT or PE (which this patient has), immobilization in past 4 weeks, or malignant disease 1
- The absence of signs of DVT, immobilization, hemoptysis, pulse >100, and malignancy makes PE highly unlikely 1
Key Clinical Features to Assess
Document the following specific findings immediately:
- Respiratory rate (tachypnea >20/min is present in most PE patients) 1
- Oxygen saturation and arterial blood gases (hypoxia and hypocapnia are frequent in PE) 1, 3
- Presence of pleuritic chest pain (highly suggestive of PE when combined with pleural effusion) 4
- Hemodynamic stability (systolic BP, heart rate, signs of right ventricular strain) 1, 2
Cough alone for one week is a nonspecific symptom that can represent lower respiratory tract infection, post-PE pleural complications, or other pulmonary conditions 1, 5, 3
Diagnostic Approach
If Clinical Probability is Low or Intermediate:
- Obtain high-sensitivity D-dimer as the initial test (not imaging) 1
- Use age-adjusted D-dimer threshold (age × 10 ng/mL for patients >50 years, rather than generic 500 ng/mL) 1
- If D-dimer is below the age-adjusted cutoff, no imaging is needed and PE is excluded 1
If Clinical Probability is High:
- Proceed directly to CT pulmonary angiography (CTPA) without D-dimer testing 1
- D-dimer testing is not useful in high-probability patients 1
Additional Baseline Testing:
- Chest radiograph (abnormal in >80% of PE cases, but also helps identify alternative diagnoses like pneumonia) 1, 3
- ECG (may show tachycardia, T wave inversion in V1-V2, or other PE-related changes) 1, 3
Alternative Diagnoses to Consider
Given the one-week duration of cough, strongly consider:
- Lower respiratory tract infection (pneumonia or acute bronchitis) - particularly if fever, productive sputum, or focal chest radiograph findings are present 1
- Pleural effusion from prior PE - nearly all PE-related effusions are exudates, frequently hemorrhagic, and can cause persistent cough 4
- Cardiac failure - especially if patient is >65 years with orthopnea, displaced apex beat, or history of myocardial infarction 1
Critical Pitfalls to Avoid
- Do not assume cough equals recurrent PE - PE typically presents with sudden onset dyspnea, not isolated subacute cough 2, 3
- Do not obtain imaging in low-probability patients without D-dimer testing first - this leads to unnecessary radiation exposure and false-positive subsegmental findings 1
- Do not delay anticoagulation if high clinical suspicion exists - start therapeutic anticoagulation while diagnostic workup is ongoing unless bleeding contraindications exist 1
Management Based on Findings
If PE is Confirmed:
- Hemodynamically stable patients: Continue or initiate direct oral anticoagulants (apixaban, rivaroxaban, edoxaban, or dabigatran) which are noninferior to warfarin with 0.6% lower bleeding rates 2
- Hemodynamically unstable patients (systolic BP <90 mm Hg): Systemic thrombolysis is recommended with 1.6% absolute mortality reduction 2
- Assess right ventricular function and biomarkers for risk stratification 1