Abstract Background: Survival for avalanche victims is time-dependent, and survival is often reliant on ground companion rescue. Due to the time-critical nature of burial, remote locations, and high frequency of concomitant severe trauma, helicopters are often dispatched to these incidents. While helicopter-based transceiver searches are standard, the most efficient deployment strategy, either using an underslung antenna or hoisting a rescue paramedic (RP) with a handheld transceiver, remains unknown. This study compared the operational efficiency of these two methods in the Norwegian Search-and-Rescue (SAR) Helicopter Service. Methods: A dual randomized, experimental field trial was conducted with the on-duty SAR helicopter and crew at the Ørland Main Airforce Base (Trøndelag, Norway). A simulated avalanche area of 80 × 150 meters was used, and six avalanche transceivers were buried at approximately 0.5m depth across the area. Only one transceiver was active at each run, and the locations were randomized to prevent crew memorization. The sequence of which procedure to use was also randomized. Four operational timestamps were recorded: First Signal, Optimal Signal, RP on Ground, and Transceiver Found. Results: Over three days, a total of 25 trial runs were performed, 13 with Antenna Search and 12 with RP Hoist Search. The RP Hoist Search was significantly faster in both time to Optimal Signal, with a difference between the groups of 29 seconds (95% CI, 9 – 50), and time for RP on Ground, with a difference between the groups of 124 seconds (95% CI, 98 – 151). For the total time to Transceiver Found, the difference between the groups was 143 seconds (95% CI, 113 – 172; P <0.001). Furthermore, the RP Hoist Search resulted in significantly faster fine search on the ground. Conclusion: This randomized, experimental field trial comparing two currently used standard search procedures in the Norwegian SAR service showed that the RP Hoist Search was significantly more efficient than the Antenna Search for localizing buried avalanche victims, reducing total localization time by more than two minutes. Given that survival probability is reduced after 10-15 minutes of burial, this time saving may be clinically significant. The findings support that RP Hoist Search is an effective localization strategy for SAR helicopter services with comparable hoist systems.
Abstract 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.
