Page 69 - JSOM Spring 2023

Motion Analysis

An Objective Assessment of Special Operations Forces and
Tactical Medics Performing Point-of-Care Ultrasound

Vincent Baribeau, BS ; Kadhiresan R. Murugappan, MD ; Aidan Sharkey, MD ;
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Derek N. Lodico, DO *; Daniel P. Walsh, MD ; Dustin C. Lin, MS ; Vanessa T. Wong, BS ;
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Jeffrey Weinstein, MD ; Robina Matyal, MD ; Feroze Mahmood, MD ; John D. Mitchell, MD 11
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ABSTRACT
Background: Point-of-care ultrasound (POCUS) is commonly which encompasses a wide range of assessment and manage-
employed to image the heart, lungs, and abdomen. Rapid ultra- ment techniques utilizing ultrasound (US) imaging, provides
sound for shock and hypotension (RUSH) exams are a critical real-time information to better manage patients in emergency,
component of POCUS employed in austere environments by military, and remote situations. The significant potential for
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Special Operations Forces (SOF) and tactical medics for triage POCUS applications in the Tactical Combat Casualty Care
and diagnosis. Despite its utility, training for POCUS remains (TCCC) setting continues to be highlighted. The RUSH
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largely unstandardized with respect to feedback and markers exam is an example of POCUS often used by medics for triage
of proficiency. We hypothesized that motion analysis could in these settings. This exam is used to evaluate the heart, lungs,
objectively identify improvement in medics’ performance of and abdomen and is a broader assessment protocol than the
RUSH exams. Furthermore, we predicted that motion met- more commonly used Focused Assessment with Sonography
rics would correlate with qualitative ratings administered for Trauma (FAST) and extended FAST (eFAST) exams for
by attending anesthesiologists. Methods: A team of civilian trauma, which screen primarily for blood.
and military attending anesthesiologists trained 24 medics in
POCUS during a 5-day course. Each medic performed eight As the use of US to diagnose and manage patients has grown,
RUSH exams using an ultrasound probe equipped with an robust training and assessment has become essential for
electromagnetic motion sensor to track total distance travelled POCUS-related skills. 1,4,5 While training programs focused
(path length), movements performed (translational motions), on individual US-guided procedures for military medics have
degrees rotated (rotational sum), and time. Instructors (ex- been implemented successfully, no comprehensive US train-
perts) observed and rated the exams on the following items: ing program with objective measures to assess performance
image finding, image fine-tuning, speed, final image accuracy, has been implemented before. 5,6–10 Furthermore, the value of
and global assessment. Motion metrics were used to provide standardized metrics to assess military medical personnel on
feedback to medics throughout the course. Generalized esti- their TCCC knowledge and procedural skills has been empha-
mating equations were used to analyze the trends of motion sized. Our team recently described a training course designed
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metrics across all trials. Correlations amongst motion metrics to teach SOF combat and tactical medics on how to effectively
and expert ratings were assessed with Pearson correlation co- use POCUS. At the time, an objective structural clinical ex-
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efficients. Results: Participants exhibited a negative trend in amination (OCSE) and a knowledge test were used to assess
all motion metrics (p < 0.001). Pearson correlation coefficients participants’ skills and knowledge in POCUS. This manuscript
revealed moderate inverse correlations amongst motion met- details how three additional cohorts of SOF medics progressed
rics and expert ratings. Conclusion: Motion analysis was able through an enhanced course that implemented additional,
to quantify and describe the performance of medics training in objective measures of performance in the form of motion
POCUS and correlated with expert ratings. analysis. Motion analysis has been previously used to assess
performance in residents learning POCUS and other proce-
Keywords: Medic; motion analysis; point-of-care ultrasound; dures. 12–15 In theory, as trainees practice a skill, their motions
pocus; rapid ultrasound for shock and hypotension become more deliberate and efficient, resulting in decreased
overall movement. Therefore, negative trends in motion met-
rics are regarded as positive indicators of performance.
Introduction
The purpose of this study was to determine whether objective
SOF combat and tactical medics routinely use POCUS in re- methods of analysis could be used to quantify improvements
mote settings to determine a casualty’s severity, evacuation in medics performing POCUS. We hypothesized that motion
priority, and to advise commanders on the most appropriate analysis could objectively identify improvements in the per-
trauma referral pathway and evacuation platform. POCUS, formance of medics learning RUSH exams. Furthermore, we

*Correspondence to jmitch28@hfhs.org
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1 Vincent Baribeau is affiliated with the Geisel School of Medicine, Hanover, NH. Dr Kadhiresan R. Murugappan, Dr Aidan Sharkey, Dr Daniel
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P. Walsh, Dr Jeffrey Weinstein, Dr Robina Matyal, and Dr Feroze Mahmood are physicians affiliated with Beth Israel Deaconess Medical
Center, Boston, MA. CDR Derek N. Lodico is a physician affiliated with the Uniformed Services University of Health Sciences, Bethesda, MD.
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6 Dustin C. Lin and Vanessa T. Wong are affiliated with Beth Israel Deaconess Medical Center, Boston, MA. Dr John D. Mitchell is a physician
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affiliated with Henry Ford Health, Detroit, MI and Michigan State University College of Human Medicine, East Lansing, MI.
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