Pulmonary embolism
most likely from an evolving right calf DVT
Pertinent history
- Long-haul flight ten days ago (Social History → Travel)
- Combined oral contraceptive pill started six weeks ago (Medications)
- Calf ache not volunteered — only surfaced when asked directly (Associated Symptoms)
- Maternal history of DVT (Family History)
Pertinent examination
- Right calf swelling and tenderness, asymmetric to the left (Cardiovascular)
- Heart rate persistently 95–100 through the consultation — relatively tachycardic for someone otherwise well-looking
- Rib tenderness on palpation (Respiratory) is a distractor: reproducible chest wall tenderness does not exclude PE
Investigations
- ECG: sinus tachycardia, rate 98, no acute ST changes (rhythm strip) — a normal ECG doesn't rule out PE
- No same-day D-dimer or CTPA were available in this GP setting — the correct action on a PE-likely Wells score was urgent same-day emergency assessment rather than waiting on a test this setting couldn't provide in time anyway
Pathophysiology & management
Oestrogen-driven hypercoagulability plus venous stasis from prolonged immobility on the flight promotes clot formation in the deep veins of the calf. A fragment embolises to the pulmonary circulation, causing local V/Q mismatch — the mechanism behind the pleuritic pain and breathlessness. Two-level Wells scoring here comes out as PE-likely, which routes straight to urgent same-day imaging rather than community D-dimer. COCP would be stopped and anticoagulation started once confirmed.
Why not the other differentials
Musculoskeletal chest pain
Doesn't explain the tachycardia, breathlessness, or calf findings. Reproducible tenderness alone isn't specific enough to close the case.
Pneumonia
No fever, no cough, clear chest, no focal signs on auscultation.
Anxiety / panic attack
Could explain tachycardia and breathlessness in isolation, but doesn't account for the calf findings or the risk factor combination — never the safe default once a PE differential is live.