Ultrasound-guided peripheral intravenous catheters insertion in patient with difficult vascular access: Short axis/out-of-plane versus long axis/in-plane, a randomized controlled trial.

No differences were found between short-axis and long-axis techniques in terms of success rate, intraprocedural pain, and local complications. Despite this, a slightly higher success rate, a lower number of venipunctures, and a higher rate of positive blood return at 72 and 96 h together with an easier ultrasound technique could suggest a short-axis approach.