atients often require venous access. The lack of a scale to predict this difficulty in the emergency department makes the validation of an instrument all the more necessary. The use of ultrasounds to locate veins makes it easier to catheter patients with difficult venous access. The ultrasound technique, and the pain or satisfaction that may result, requires further examination and comparisons with the traditional technique. Research conducted with a mixed quantitative and qualitative methodology that consisted of three stages: the validation of an instrument to measure puncture difficulty for peripheral intravenous catheterization (A-DICAVE scale). Qualitative phenomenological study. Conclusions: The A-DICAVE scale is a valid and reliable...