Question

A 58-year-old man presents to the emergency department with sudden pleuritic chest pain and dyspnoea. He has a history of recent knee replacement surgery. Vital signs: BP 122/78 mmHg, HR 104 beats/min, RR 24 breaths/min, SpO₂ 93% on room air. Clinical examination is otherwise unremarkable. What is the most appropriate next step in diagnostic evaluation according to evidence-based PE assessment strategies?

Accepted Answer

Apply a validated pre-test probability tool (e.g., Wells score) and use D-dimer to rule out PE in low-probability patients

Answer

Order CT pulmonary angiography immediately without further assessment

Answer

Request a D-dimer test without clinical probability assessment

Answer

Start anticoagulation and defer imaging for 48 hours

Answer

Order a ventilation-perfusion (V/Q) scan in all patients with suspected PE regardless of risk

Practice question