Abstract
Background and Objectives: Peripheral vascular access in infants is a frequent but technically challenging procedure due to the anatomical characteristics of this population. Repeated failed attempts may increase complications and emotional stress for both patients and healthcare professionals. This systematic review aimed to evaluate the efficacy and safety of ultrasound-guided peripheral vascular cannulation compared to the conventional or "blind" technique in infants. Materials and Methods: A systematic review was conducted in accordance with PRISMA guidelines. The PubMed database was searched for studies published between 2017 and 2025. Studies comparing both techniques in infants under two years of age were selected, evaluating variables such as the number of punctures, first-attempt success, healthcare staff perception, associated stress, and the role of simulation in training. Results: Eleven studies were included, comprising clinical trials, observational studies, and training program assessments from different countries. Most reported a higher first-attempt success rate with the ultrasound-guided technique (often exceeding 85%), along with fewer punctures and complications, particularly among less-experienced professionals. Improvements in staff perception were also observed following structured training. The impact on stress experienced by patients and families was less frequently assessed directly, although some studies reported indirect benefits. Conclusions: Ultrasound-guided peripheral vascular cannulation appears to be more effective and safer than the conventional technique in infants, particularly in complex or critical care contexts. Its implementation requires specific training and appropriate resources but could significantly improve clinical outcomes and the pediatric patient experience.