Randomized study of teaching ultrasound-guided vascular cannulation using a phantom and the freehand versus needle...

The task of ultrasound-guided vessel cannulation can be technically difficult. Needle guides have been designed to facilitate vessel puncture. We aimed to identify and compare the learning curves of participants performing vessel puncture with conventional freehand (FH) and needle guide-assisted (NG) techniques.

Thirty-six participants were randomly allocated to either the FH or the NG group. They were asked to consecutively perform as many as 30 vessel punctures on a simulated phantom model. Quantitative metrics (time taken and number of skin and posterior-wall punctures) were recorded and compared between the two groups. The cumulative sum and moving F-test statistical methods were used to delineate the learning curves.

There was a significantly lower rate of posterior-wall punctures in the NG group than in the FH group (15% versus 26%; p < 0.0001). Participants in the NG group also performed significantly fewer skin punctures than did those in the FH group (mean, 405 versus 515; p < 0.0001). Cumulative sum statistical method analysis showed that participants in the NG group surmounted the learning curve earlier (13 attempts; interquartile range, 10.3-17.0) than did those in the FH group (19 attempts; interquartile range, 15.0-27.5). The number of attempts to surmount the learning curve was significantly less for the FH group (7.2 versus 16 attempts; p = 0.007) when using the moving F-test.

The NG puncture allows a greater number of trainees to cross the learning threshold and offers the advantages of fewer posterior-wall punctures and skin punctures. The use of NG puncture may result in a shorter path to proficiency, allowing trainees to attempt needle puncture earlier and with a greater degree of safety.