From the Guidelines
The approach to rule out pulmonary embolism (PE) involves a stepwise process combining clinical assessment, risk stratification, and diagnostic testing, as recommended by the American College of Physicians 1.
Key Steps in the Approach
- Begin with clinical evaluation using validated tools like the Wells score or PERC (Pulmonary Embolism Rule-out Criteria) to determine pre-test probability.
- For low-risk patients who meet all PERC criteria, PE can be safely ruled out without further testing.
- For patients with low to intermediate risk, a D-dimer blood test should be ordered; a negative D-dimer (<500 ng/mL) effectively excludes PE in this population.
- If D-dimer is elevated or if the patient has high pre-test probability, imaging is required.
Imaging Options
- CT pulmonary angiography (CTPA) is the standard imaging test, providing direct visualization of emboli in the pulmonary arteries.
- In patients with contraindications to CTPA (such as renal dysfunction or contrast allergy), ventilation-perfusion (V/Q) scanning is an alternative.
- For pregnant patients, compression ultrasonography of the legs may be performed first to detect deep vein thrombosis, potentially avoiding radiation exposure.
Rationale
This systematic approach balances the risks of missing a potentially fatal diagnosis against unnecessary testing and radiation exposure, with decisions guided by the individual patient's risk factors, clinical presentation, and test results, as supported by the evidence from the American College of Physicians 1.
From the FDA Drug Label
- 3 Treatment of Pulmonary Embolism XARELTO is indicated for the treatment of pulmonary embolism (PE). The approach to rule out pulmonary embolism (PE) is not directly addressed in the provided drug label. Key points:
- The label discusses the treatment of PE with XARELTO, but does not provide information on how to rule out PE.
- There is no mention of a specific approach or diagnostic criteria for ruling out PE. 2
From the Research
Approach to Rule Out Pulmonary Embolism (PE)
The approach to rule out pulmonary embolism (PE) involves a combination of clinical probability assessment and diagnostic tests.
- Clinical probability assessment is used to determine the likelihood of PE in a patient, with categories ranging from low to high probability.
- Diagnostic tests, such as D-dimer testing, lung scans, and compression ultrasonography, are used to confirm or rule out PE.
Diagnostic Tests
- D-dimer testing is a commonly used test to rule out PE, with a normal result indicating a low likelihood of PE 3, 4, 5.
- Lung scans, such as ventilation-perfusion scans, can be used to diagnose PE, especially in patients with a low clinical probability and a nondiagnostic lung scan 6.
- Compression ultrasonography is used to detect deep vein thrombosis, which can be a sign of PE 6.
Clinical Decision Rules
- Clinical decision rules, such as the Wells score, can be used to assess clinical probability and guide diagnostic testing 7.
- The combination of a low clinical probability and a normal D-dimer result can be used to rule out PE, with a high negative predictive value 3, 4, 5.
Management Strategies
- Patients with a low clinical probability and a normal D-dimer result can be safely discharged without further testing or anticoagulant therapy 3, 4, 5.
- Patients with a moderate or high clinical probability require further testing, such as computed tomographic pulmonary angiography, to confirm or rule out PE 5.
- The use of a combination of clinical probability assessment and D-dimer testing can reduce the need for chest imaging and anticoagulant therapy, while maintaining a low risk of missed PE diagnoses 5.