Emergency Life-Saving Technician-Performed Focused Assessment with Sonography for Trauma in Moving Ambulances: A Pilot Innovation Report
Kohei Ageta, Chiaki Kuriyama, Akiko Ohira, Hikaru Oba, Jota Maki, Toshiharu Mitsuhashi, Jun Sakurai, Yoshinobu MaedaAbstract
Introduction:
In Japan, Emergency Life-Saving Technicians (ELSTs) cannot independently perform diagnostic ultrasound under the current legal framework. If ELST-performed focused assessment with sonography for trauma (FAST) is to be introduced in the prehospital setting, technical feasibility during ambulance motion and the viability of remote physician observation must be established.
Study Objective:
The study aimed to evaluate the feasibility of ELST-performed FAST in moving ambulances in a controlled manikin setting and to descriptively assess an integrated monitoring system for remote observation.
Methods:
A prospective observational pilot study was conducted at the Okayama City Fire Department Training Center in Okayama Prefecture, Japan on March 3, 2025. Twenty ELSTs completed structured e-learning and a hands-on workshop using standardized FAST/ER FAN manikins. Participants performed FAST under three fixed-order conditions: stationary (STOP), 15km/hour, and 30km/hour on a 250-m circular course. The primary outcome was the total Task-Specific Checklist (TSC) score (0-24 points). Secondary outcomes were examination time, site-specific TSC subscores, inter-rater agreement, and a descriptive assessment of transmitted image quality by two specialist physicians.
Results:
All 20 ELSTs completed the study. Mean total TSC scores were 23.4 (SD = 0.8) in the STOP condition, 23.4 (SD = 0.9) at 15km/hour, and 23.7 (SD = 0.6) at 30km/hour. Compared with the STOP condition, the mean difference in total TSC score was 0.08 points (95% CI, −0.24 to 0.39; P for noninferiority < 0.001) at 15km/hour and 0.33 points (95% CI, −0.04 to 0.69; P for noninferiority < 0.001) at 30km/hour. Both moving conditions met the pre-specified noninferiority criterion relative to the STOP condition. Mean examination times were 36.7 (SD = 14.4) seconds in the STOP condition, 30.3 (SD = 9.8) seconds at 15km/hour, and 31.9 (SD = 14.8) seconds at 30km/hour. Inter-rater agreement for TSC scoring was moderate (weighted kappa, 0.56). Descriptive ratings suggested that transmitted image quality was generally favorable for remote review in this controlled setting.
Conclusions:
In this controlled manikin-based pilot study, ELST-performed FAST was technically feasible during moderate ambulance motion, and remote physician observation was feasible. These findings may help inform staged prehospital ultrasound training and future clinical validation under legal and operational constraints.