Comparing static versus dynamic ultrasound techniques: A randomized pilot trial of novice and advanced users

Ultrasound training requires proper instruction and guidance tailored both to novice and advanced ultrasound users. The aim of the current investigation was to compare the performance of novice and advanced sonographers using a tofu model for IV cannula placement using either ultrasound static (US) or dynamic (UD) techniques.

Eighty volunteers were allocated to either the novice or advanced group according to prior ultrasonography experience. Participants were randomly assigned (1:1) to either the US or UD group. A modified version of the global rating scale was used to assess performance. The primary outcome was the assessment scale composite score. Secondary outcomes included time to procedure completion and the number of needle passes.

In the novice cohort, the US group scored significantly higher than participants in the UD, median difference 9 (95% CI: 0-19), p = 0.01. In the advanced cohort, there was no difference in the performance score. Advanced participants performed the UD technique in less time than those using the US technique, 28.5 s (IQR 24-40) vs 42.5 s (IQR 30-55), median difference 14 (95% CI: 1-27), p = 0.02, respectively. Novices showed no difference in time to completion for either technique. In the novice cohort, the number of needle passes was less in the US group, median of 1 (IQR 1-2) compared to the UD group, median of 2 (IQR 1-3.75), median difference -1 (95% CI: -2 to 0), p = 0.03. There was no difference in the number of needle passes in either techniques involving the advanced users.

Compared to the real time UD method, the US technique for intravenous cannulation is more fitted for novice users and should be considered more widely as the introductory technique to improve their procedural efficiency of ultrasound guided intravenous cannulation.