Enhancing the quality and safety of central venous catheter insertion using projection mapping: a prospective observational simulation study with eye-tracking glasses.

Objectives: We aimed to evaluate the effect of projection mapping (PM) on the quality and safety of central venous catheter (CVC) insertion under real-time ultrasound guidance.

Design: Prospective, observational, simulation study.

Setting: This study was conducted at the Yokohama City University Medical Center (Yokohama, Japan). Volunteer residents were enrolled over 12 months from January to December 2023.

Participants and methods: 12 rotating residents (postgraduation year (PGY) 1 and 2) and eight anaesthesia residents (PGY 3-5) placed the CVC in the internal jugular vein in a simulator under the real-time ultrasound guidance using the short-axis out-of-plane approach. The ultrasound image was provided either just caudad to the puncture site using the PM method or on the monitor of the ultrasound machine (conventional method) placed next to the simulator's right shoulder. Each resident performed four punctures alternating between the PM and conventional methods, and the first method for each resident was chosen randomly. Eye-tracking analysis was also used to evaluate differences in gaze behaviour.

Primary and secondary outcome measures: The primary outcome was the procedure time defined as the time from the application of the ultrasound probe on the puncture field until successful puncture of the vein. The secondary outcomes were incidence of complications and eye-tracking analysis data.

Results: The time to complete the line placement was significantly shorter for the PM than for the conventional method (median (IQR) 22.5 (15.5-30.6) s vs 30.0 (20.4-95.4) s; p=0.02, Wilcoxon's signed-rank test). The incidence of posterior vessel wall puncture was significantly lower in the PM method (0% vs 25%; p=0.02, McNemar's test). Eye-tracking analysis revealed that the percentage of time spent gazing at the ultrasound image was higher in the PM than in the conventional method (61.6% (55.0-69.2) vs 45.7% (34.1-54.5); p<0.01).

Conclusions: The PM method facilitates ultrasound-guided CVC placement while preventing excessive needle advancement in the inexperienced operators. This was accompanied by enhanced fixation of the participants' line-of-sight on the ultrasound image.