Combat Medic eFAST with Novel and Conventional Portable Ultrasound Devices: A Prospective, Randomized, Crossover Trial.

BACKGROUND: Extended Focused Assessment with Ultrasonography in Trauma (eFAST) reliably identifies noncompressible torso hemorrhage (NCTH), a major cause of battlefield death. Increased portability of ultrasound enables eFAST far forward on the battlefield, and published data demonstrate combat medics can learn and reliably perform ultrasound exams. One medical company developed an ultrasound device with an intuitive graphical user interface (GUI) and novel, finger-worn transducer with built-in linear and phased arrays, referred to as the novel device. We evaluated combat medic eFAST performance between the novel and conventional device. METHODS: This was a prospective, randomized, crossover trial completed at a single US military installation. Subjects were US Army combat medics with no previous ultrasound experience. Subjects performed an eFAST on a live human and a simulation model with both devices after a brief training intervention. Our primary outcome was time in seconds for eFAST completion, limited to 600 seconds. Secondary outcomes included diagnostic accuracy, technical adequacy using a validated task-specific checklist, and end-user appraisal of device ease-of-use with 5-point Likert items. This study was approved by the local institutional review board. RESULTS: Forty subjects volunteered, most were male (67.5%), less than 36 years old (95.0%), and grade E-4 or below (75.0%). Subjects performed a total of 160 eFAST scans (80 novel, 80 conventional). We found no significant difference in time for eFAST completion between the novel and conventional devices (391 seconds [95% CI 364, 417] versus 352 seconds [95% CI 325, 379]; p = 0.71). We also found no significant differences between the novel and conventional devices with respect to diagnostic accuracy (91.5% versus 89.2%; p = 0.28) and technical adequacy (75.0% versus 72.5%; p = 0.28). However, we did find that subjects favored the image quality of the novel device (4.3 versus 3.6; p is less than 0.01), while favoring the conventional transducer (3.8 versus 4.3; p = 0.04). CONCLUSION: Combat medic eFAST performance utilizing both devices did not differ with respect to time to completion, diagnostic accuracy, and technical adequacy. Medics with limited ultrasound experience performed diagnostically accurate eFAST after a brief training intervention. Future research should assess learning gaps and skill retention in order to guide development of US military ultrasound training programs for combat medics.

FAST Performance in a Stationary versus In-Motion Military Ambulance Utilizing Handheld Ultrasound: A Randomized Controlled Study.

OBJECTIVE: On-scene prehospital conditions and patient instability may warrant a during-transport ultrasound (US) exam. The objective of this study was to assess the effect of ambulance turbulence on the performance of the Focused Assessment with Sonography in Trauma (FAST) with a handheld US device. METHODS: This was a randomized controlled trial in which participants were randomized to perform a FAST in either a stationary or an in-motion military ambulance. Participants were physicians and physician assistants (PAs) with previous FAST training. All exams were performed on an US phantom model. The primary outcome was FAST completion time, reported as a mean, in seconds. Secondary outcomes included image acquisition score (range of 0-24, reported as a mean), diagnostic accuracy (reported as sensitivity and specificity), and a post-participation survey with five-item Likert-type scales. RESULTS: Twenty-seven participants performed 27 FASTs, 14 in the stationary ambulance and 13 in the in-motion ambulance. All participants obtained the four requisite views of the FAST. A significant difference was detected in image acquisition scores in favor of the stationary ambulance group (19.4 versus 16.7 [95% CI for difference, 0.9-4.4]; P <.01). Significant differences in survey items between groups were related to obtaining and maintaining US images and the exam conditions. There was not a difference in FAST completion time between groups (98.5 seconds versus 78.7 seconds [95% CI for difference, -13.5 seconds to 53.1 seconds]; P = .23). Sensitivity and specificity of FAST in the stationary ambulance was 85.7% (95% CI, 67.3%-96.0%) and 96.4% (95% CI, 81.7%-99.9%) versus 96.2% (95% CI, 80.4%-99.9%) and 100.0% (95% CI, 86.8%-100.0%) in the in-motion ambulance group (P = .21). CONCLUSION: Vehicular motion did not affect FAST completion time and diagnostic accuracy; however, it did reduce FAST image acquisition scores. The results suggest timely and diagnostically accurate FASTs may be completed by experienced sonographers during moderate levels of ambulance turbulence. Further investigation assessing the utility and limitations of newer handheld US devices in various prehospital conditions is warranted.

Impact of a 4-hour Introductory eFAST Training Intervention Among Ultrasound-Naïve U.S. Military Medics.

INTRODUCTION: Advances in the portability of ultrasound have allowed it to be increasingly employed at the point of care in austere settings. Battlefield constraints often limit the availability of medical officers throughout the operational environment, leading to increased interest in whether highly portable ultrasound devices can be employed by military medics to enhance their provision of combat casualty care. Data evaluating optimal training for effective medic employment of ultrasound is limited however. This prospective observational cohort study's primary objective was to assess the impact of a 4-hour introductory training intervention on ultrasound-naïve military medic participants' knowledge/performance of the eFAST application. MATERIALS AND METHODS: Conventional U.S. Army Medics, all naïve to ultrasound, were recruited from across JBLM. Volunteer participants underwent baseline eFAST knowledge assessment via a 50-question multiple-choice exam. Participants were then randomized to receive either conventional, expert-led classroom didactic training or didactic training via an online, asynchronously available platform. All participants then underwent expert-led, small group hands-on training and practice. Participants' eFAST performance was then assessed with both live and phantom models, followed by a post-course knowledge exam. Concurrently, emergency medicine (EM) resident physician volunteers, serving as standard criterion for trained personnel, underwent the same OSCE assessments, followed by a written exam to assess their baseline eFAST knowledge. Primary outcome measures included (1) post-course knowledge improvement, (2) eFAST exam technical adequacy, and (3) eFAST exam OSCE score. Secondary outcome measures were time to exam completion and diagnostic accuracy rate for hemoperitoneum and hemopericardium. These outcome measures were then compared across medic cohorts and to those of the EM resident physician cohort. RESULTS: A total of 34 medics completed the study. After 4 hours of ultrasound training, overall eFAST knowledge among the 34 medics improved from a baseline mean of 27% on the pretest to 83% post-test. For eFAST exam performance, the medics scored an average of 20.8 out of a maximum of 22 points on the OSCE. There were no statistically significant differences between the medics who received asynchronous learning versus traditional classroom-based learning, and the medics demonstrated comparable performance to previously trained EM resident physicians. CONCLUSIONS: A 4-hour introductory eFAST training intervention can effectively train conventional military medics to perform the eFAST exam. Online, asynchronously available platforms may effectively mitigate some of the resource requirement burden associated with point-of-care ultrasound training. Future studies evaluating medic eFAST performance on real-world battlefield trauma patients are needed. Skill and knowledge retention must also be assessed for this degradable skill to determine frequency of refresher training when not regularly performed.

U.S. Army Combat Medic eFAST Performance with a Novel Versus Conventional Transducers: A Randomized, Crossover Trial.

BACKGROUND: Point-of-injury extended focused assessment with sonography in trauma (eFAST) may identify life-threatening torso hemorrhage and expedite casualty evacuation. The purpose of this study was to compare combat medic eFAST performance between the novel and conventional ultrasound (US) transducers. METHODS: We conducted a randomized crossover trial. Medic participants, previously naïve to US, were randomized to the type of transducer first utilized. The primary outcome was eFAST completion time in seconds. Secondary outcomes included diagnostic accuracy, technical adequacy, and transducer ease-of-use rating. RESULTS: Forty medics performed 160 eFASTs. We found a statistically significant difference in eFAST completion times in favor of conventional transducers (304 vs. 358 s; P = 0.03). There was no statistically significant difference between the conventional and novel transducers in terms of diagnostic accuracy (97.7% vs. 96.0%; P = 0.25) and technical adequacy (65% vs. 72.5%; P = 0.11). Median transducer ease-of-use rating (Likert 1-5 scale) was statistically significant in favor of the conventional transducers (5 vs. 4; P = < 0.001). CONCLUSIONS: Extended focused assessment with sonography in trauma exam times was faster with the conventional transducers. Combat medics performed diagnostically accurate eFASTs with both transducer types in a simulated aid station setting after a brief training intervention. Conventional transducers were rated higher for ease-of-use.

A Case of Delayed Traumatic Vertebral Artery Dissection.

Vertebral artery dissection is of special clinical importance because of its often-delayed presentation and the risk of potentially permanent neurological deficit, or even death, as a result of injury. Once a rarely discovered injury, the better availability and use of computed tomography and magnetic resonance imaging have contributed to an increased incidence. Early diagnosis and treatment can almost eliminate the threat of acute cerebral vascular injury and save lives. In this report, we review a case of delayed traumatic vertebral artery dissection and discuss the key clinical findings and management strategies.