Advanced Patient Assessment Practice Exam

A patient presents with acute shortness of breath and chest pain. What is the most likely initial test to evaluate for a possible pulmonary embolism?

1. X-ray chest

2. Electrocardiogram

3. D-dimer

4. CT pulmonary angiography

The correct answer is: D-dimer

In the evaluation of acute shortness of breath and chest pain, especially when considering a potential pulmonary embolism (PE), a D-dimer test is often used as an initial screening tool. The D-dimer is a fibrin degradation product that is typically elevated in the setting of thrombosis, including conditions such as PE. When a patient has symptoms suggestive of a PE, measuring D-dimer levels can help to rule out the presence of significant thrombus. A normal D-dimer level is generally indicative that a PE is less likely; conversely, an elevated D-dimer level suggests that further imaging or testing may be warranted to confirm or rule out a PE. While imaging studies like CT pulmonary angiography are definitive for diagnosing PE, the D-dimer serves as a more accessible, non-invasive first step for determining the likelihood of thrombosis. It's important to note that while an elevated D-dimer doesn't confirm a PE, it can prompt further investigation, aligning with a clinical decision-making approach that balances cost, efficiency, and patient safety.