Acoustic shadowing combined with dynamic needle tip positioning facilitates teaching of ultrasound guided radial artery cannulation in standardized training for residents: a randomized controlled trial

Background: Radial artery cannulation is challenging for residents, so it is necessary to establish a simple teaching strategy. The aim of this study was to evaluate the efficiency of three ultrasound-guided radial artery cannulation techniques in the standardized training of residents. Methods: 93 residents, who had not performed radial artery cannulation, undergoing standardized residency training in the Department of Anaesthesiology were randomly divided into a traditional ultrasound-guided teaching group (Group C), acoustic shadowing-facilitated ultrasound-guided teaching group (Group AS); and acoustic shadowing combined with dynamic needle tip positioning-facilitated ultrasound-guided teaching group (Group AS-D). Residents received theoretical and practical training before the assessment. After the training, the first-attempt puncture success rate, first-attempt cannulation success rate, ultrasound localization time and puncture time were compared uniformly among the three groups. Results: The success rate of first puncture was similar in the AS-D and AS groups and was higher than that in group C. However, the success rate of first-attempt cannulation was significantly higher in the AS-D group than in the AS group, and the incidence of local haematoma was lower. In addition, the ultrasound localization time was shorter in both AS-D and AS groups compared with group C. However, the puncture time was significantly longer in the AS-D group than in the AS group. Conclusion: Acoustic shadowing combined with dynamic needle tip positioning-facilitated ultrasound-guided radial artery cannulation improves the success rate of the first-attempt cannulation, which is beneficial in the standardized training and teaching of residents.