A PATIENT AGED 33 YEARS WITH AN UNEXPLAINED SWELLING OF ONE LEG FOR THE LAST 2 MONTHS PRESENTS WITH 14 DAYS OF EFFORT INTOLERANCE DUE TO BREATHLESSNESS AND HAEMOPTYSIS. EXAMINATION SHOWS BREATHLESSNESS, A HEART RATE OF 110 BPM, BP 125/65, OXYGEN SATURATIONS ON AIR OF 90%, AND AN ECG SHOWING SINUS TACHYCARDIA AND RIGHT AXIS DEVIATION. WHICH OF THE FOLLOWING IS TRUE

• A. A D-dimer should be performed
• B. Immediate thrombolysis should be given
• C. A CT pulmonary angiogram should be undertaken immediately, and, if not possible, a cardiac ultrasound ✓
• D. Warfarin should be given without any further investigation
• E. A chest X-ray is unnecessary

In this scenario, the patient presents with several concerning symptoms including unexplained swelling of one leg, effort intolerance due to breathlessness, and haemoptysis. The clinical findings of breathlessness, tachycardia, low oxygen saturations, and ECG changes suggestive of right heart strain raise suspicion for a possible pulmonary embolism (PE). Given the acute onset of symptoms and the presence of risk factors such as leg swelling and hemoptysis, prompt evaluation for PE is warranted.

Reasoning:

1. D-dimer Testing: While D-dimer testing is a useful screening tool for suspected PE, it is not specific and can be elevated in various conditions. In this case, the patient’s presentation with symptoms suggestive of PE warrants further imaging to confirm the diagnosis rather than relying solely on D-dimer testing.
2. Immediate Thrombolysis: Immediate thrombolysis is not recommended without confirming the diagnosis of PE through imaging studies. Thrombolytic therapy carries risks of bleeding complications and should only be initiated after confirming the presence of a significant clot burden in the pulmonary arteries.
3. CT Pulmonary Angiogram (CTPA): CTPA is considered the gold standard imaging modality for diagnosing PE due to its high sensitivity and specificity. Given the high clinical suspicion in this case, an immediate CTPA should be performed to confirm or exclude the presence of pulmonary embolism.
4. Cardiac Ultrasound: If CTPA is not immediately available or contraindicated, a bedside echocardiogram can be performed to assess for signs of right heart strain such as right ventricular dilation or dysfunction. This can provide additional supportive evidence for the diagnosis of PE.
5. Warfarin Therapy: Initiating anticoagulation with warfarin without confirming the diagnosis through imaging studies is not recommended. Anticoagulation should be based on a confirmed diagnosis of PE to prevent unnecessary risks associated with long-term anticoagulant therapy.
6. Chest X-ray: While a chest X-ray may show nonspecific findings such as atelectasis or pleural effusion in patients with PE, it is not sensitive or specific enough to diagnose or exclude pulmonary embolism definitively. In this case, given the high clinical suspicion for PE based on the patient’s presentation, immediate advanced imaging with CTPA is warranted.

Therefore, based on the clinical presentation and guidelines for suspected pulmonary embolism, option C. A CT pulmonary angiogram should be undertaken immediately, and if not possible, a cardiac ultrasound is the most appropriate course of action in this scenario.