A 68-year-old woman on warfarin for atrial fibrillation presents with severe epistaxis. Anterior rhinoscopy shows bleeding from the anteroinferior part of the nasal septum. After initial hemostasis, which investigation is most appropriate to identify the underlying vascular source before definitive management?

## Clinical Context A 68-year-old on warfarin with severe epistaxis from the anteroinferior nasal septum suggests a **bleeding disorder** (anticoagulation) combined with a **structural vascular source**. While coagulation correction is necessary, identifying the vascular lesion is critical for definitive management. ## Why CT Angiography is the Best Investigation **Key Point:** Contrast-enhanced CT angiography (CTA) is the investigation of choice to identify and localize the bleeding vessel (typically a branch of the sphenopalatine or anterior ethmoidal artery) before definitive intervention. ### Advantages of CTA: 1. **High sensitivity** — directly visualizes the bleeding artery and its branches 2. **Precise localization** — guides endoscopic cautery or angiographic embolization 3. **Non-invasive** — safer than conventional angiography in an anticoagulated patient 4. **Rapid acquisition** — suitable for acute hemorrhage management 5. **Defines anatomy** — identifies aberrant vessels or aneurysms ## Role of Each Investigation | Investigation | Role | Timing | |---|---|---| | **Coagulation profile** | Assess INR/aPTT; guide warfarin reversal | **Concurrent** (parallel to imaging) | | **CT angiography** | **Localize the bleeding vessel** | **Before definitive hemostasis** | | **Nasal endoscopy under GA** | **Therapeutic** — cautery or packing after vessel identified | **After CTA** | | **Doppler ultrasound** | Low sensitivity; not standard for epistaxis | Not recommended | **High-Yield:** In **recurrent or severe epistaxis**, always obtain **CTA before endoscopic intervention** to avoid blind cautery and ensure you target the correct vessel. ## Clinical Pearl Anticoagulation (warfarin) is a **risk factor** for epistaxis but not the primary cause — the underlying vascular lesion (often a septal artery aneurysm or hypertrophic vessel) must be identified and treated. Correcting INR alone will not prevent recurrence if the structural lesion is not addressed.