Ultrasound guidance versus near-infrared light versus the standard technique for first-attempt success of peripheral intravenous catheterisation in adults with difficult venous access in a medical imaging department (RÉUSSIR-VVP): protocol for a single-centre, three arms, randomised controlled trial

Introduction: Peripheral intravenous catheterisation fails at the first attempt in about one in four adults and far more often in patients with difficult intravenous access (DIVA). Repeated attempts increase pain, anxiety, infection and extravasation risk, delay imaging, consume staff time and costs. Ultrasound guidance and near-infrared (NIR) vein illumination can each improve cannulation but no trial has directly compared them in a population defined by a validated DIVA Score. We aim to compare first-attempt cannulation success between the standard technique, ultrasound guidance and NIR illumination in adults with difficult venous access referred for imaging.