Ultrasound-guided dynamic needle tip positioning versus conventional palpation for improving the success rate of radial artery catheterization: A randomized controlled trial

Background: Ultrasound guidance enhances arterial catheterization by enabling real-time visualization. Various ultrasound-assisted techniques have been described. This study evaluated the clinical utility of ultrasound-guided dynamic needle tip positioning (DNTP) for radial artery catheterization compared with traditional palpation. Methods: Our study included 160 patients scheduled for elective surgery at Foshan Hospital of Traditional Chinese Medicine from February 2024 to March 2025. They were randomly assigned to either the traditional palpation group ( n = 80) or the DNTP group ( n = 80) via a web-based randomization tool. In accordance with the intention-to-treat (ITT) principle, all 160 randomized patients were included in the primary analysis. Outcomes included first-attempt success, overall success, procedure time, catheter use, and complications. Subgroup analyses were based on arterial depth and cross-sectional area. Results: The DNTP group achieved significantly higher first-attempt and overall success rates than the palpation group (80/80, 100.00% vs 65/80, 81.25% and 80/80, 100.00% vs 66/80, 82.50%; all p < 0.001). Median procedure time was shorter with DNTP (27.5 s (12–98)) compared with palpation (35 s (20–173); p = 0.039). Successful cannulation within 3 min using a single attempt occurred in 100.00% (80/80) of DNTP cases versus 81.25% (65/80) in the palpation group ( p < 0.001). Single-catheter use was more frequent in the DNTP group (80/80, 100.00%) than in the palpation group (73/80, 91.25%; p = 0.007). Complication rates were significantly lower with DNTP (13/80, 16.25%) compared with palpation (40/80, 50.00%; p < 0.001). Stratified analyses showed greater benefits of DNTP in patients with deeper arteries (>2 mm) and smaller cross-sectional areas (⩽3 mm 2 ), with significant treatment–subgroup interactions for arterial depth ( p = 0.021) and cross-sectional area ( p = 0.008). Conclusions: Ultrasound-guided DNTP significantly improves the success rate, efficiency, and safety of radial artery catheterization, particularly in patients with unfavorable arterial anatomy.