From the Guidelines
When considering a workup to rule out pulmonary embolism (PE), focus on key symptoms including unexplained shortness of breath, chest pain—particularly pleuritic chest or back pain—tachycardia, apprehension or tachypnea, syncope, and hypoxemia, as outlined in the NCCN Clinical Practice Guidelines in Oncology, Version 2.2024 1.
Key Symptoms to Consider
- Unexplained shortness of breath
- Chest pain, particularly pleuritic chest or back pain
- Tachycardia
- Apprehension or tachypnea
- Syncope
- Hypoxemia These symptoms are crucial in identifying patients who may require further evaluation for PE. The workup for PE should prioritize these symptoms, as they are commonly associated with the condition, with dyspnea, pain, and tachypnea present in 85%, 40%, and 29% of patients with PE, respectively, according to the MASTER registry 1.
Diagnostic Approach
The diagnostic approach for PE should involve a comprehensive medical history and physical examination, followed by laboratory tests and imaging studies as needed. The NCCN guidelines recommend a workup that includes:
- Comprehensive medical history and physical examination
- CBC with platelet count
- PT, aPTT
- Liver and kidney function tests
- N-terminal prohormone B-type natriuretic peptide evaluation
- Chest x-ray
- Electrocardiogram
- CT pulmonary angiography (CTA) as the preferred imaging technique for the initial diagnosis of PE
Imaging Studies
CTA is the gold standard imaging test for diagnosing PE, offering accurate imaging of mediastinal and parenchymal structures, as well as visualization of emboli in many regions of the pulmonary vasculature 1. Alternative imaging modalities, such as ventilation-perfusion (VQ) scans, may be used in patients with contraindications to CTA.
Risk Assessment
Risk assessment should begin with clinical decision tools like the Wells score or PERC rule, as recommended by the American College of Physicians 1. For patients with moderate to high pretest probability, a D-dimer blood test should be ordered, and if elevated, imaging studies should be prompted. The American College of Radiology also recommends the use of clinical scoring algorithms, such as the Wells criteria and the Geneva score, to guide the diagnostic evaluation of patients with suspected PE 1.
Patient-Specific Considerations
Patients with suspected PE and hemodynamic instability should receive immediate imaging and potential treatment without delay. PE should be considered particularly in patients with risk factors such as immobility, recent surgery, cancer, pregnancy, oral contraceptive use, or history of clotting disorders, as these conditions increase the likelihood of thrombus formation and subsequent embolism. The ACR Appropriateness Criteria also highlight the importance of considering PE in pregnant patients, as it is a leading cause of pregnancy-related mortality in the developed world 1.
From the Research
Symptoms to Consider for Workup to Rule Out Pulmonary Embolism
The following symptoms should be considered when working up a patient to rule out pulmonary embolism:
- Sudden onset dyspnea 2, 3
- Chest pain 2, 3
- Syncope or fainting 2, 3
- Hemoptysis 2, 3
- Limb swelling 3
- Unilateral leg swelling 4
Clinical Presentation and Risk Stratification
Pulmonary embolism presents with a spectrum of symptoms, ranging from asymptomatic cases to life-threatening events 3. The clinical presentation varies based on thrombus burden, demographics, and time to presentation 3. Risk stratification using tools like Wells score, Pulmonary Embolism Severity Index, and Hestia criteria aids in determining the severity of PE 3.
Diagnostic Evaluation
Diagnostic evaluation involves assessing symptoms, physical examination findings, and utilizing laboratory tests, including D-dimer 3, 5. The diagnosis is determined by chest imaging 4. In patients with a systolic blood pressure of at least 90 mm Hg, the following 3 steps can be used to evaluate a patient with possible PE: assessment of the clinical probability of PE, D-dimer testing if indicated, and chest imaging if indicated 4.
Exclusion of Pulmonary Embolism
Pulmonary embolism need not be pursued in patients with no symptoms of PE in the present or recent history (dyspnea, chest pain, cough or syncope), and always normal vital signs 5. When clinicians have a low clinical suspicion for PE or a Wells score<2, they can reasonably exclude PE with the Pulmonary Embolism Rule out Criteria (PERC rule) 5. For patients with a "PE-unlikely" pretest probability (Wells or simplified revised Geneva score<5), PE can be ruled out with a normal or age-adjusted D-dimer concentrations 5.