Which laboratory test is primarily monitored for pulmonary embolism (PE)?

• A. D-dimer
• B. Troponin
• C. Creatinine
• D. Complete Blood Count (CBC)

Answer: (A)

The primary laboratory test monitored for pulmonary embolism (PE) is D-dimer. This test measures the presence of fibrin degradation products in the blood, which are generated when a blood clot dissolves. Elevated levels of D-dimer can indicate the presence of an abnormal clotting process, such as that seen in PE. While D-dimer is not specific and can be elevated in other conditions, a significantly increased level can support the diagnosis of PE when considered alongside clinical evaluation and imaging studies.

In patients suspected of having a PE, a negative D-dimer test can help rule out the possibility of a clot, thus guiding further diagnostic steps. However, if the D-dimer is positive, it prompts further investigation, often through imaging studies like a CT pulmonary angiogram.

While troponin is important in assessing for heart injury, especially during acute coronary events, it is not specific for PE. Creatinine levels are used to assess kidney function, and a complete blood count can provide information about overall health but is not directly related to the diagnosis of PE.