Training Systems for Female Trauma and Prolonged Casualty Care: Time for New Approaches
Authors
William Y. Pike, PhD1, Mark V. Mazzeo, MS1
1US Army Combat Capabilities Development Command Soldier Center Simulation and Training Technology Center, Orlando, Florida
Conflict of Interest Statement
The authors declare no conflict of interest.
Corresponding Author
William Y. Pike, PhD, US Army Combat Capabilities Development Command Soldier Center Simulation and Training Technology Center, Orlando, Florida
(Email: William.y.pike.civ@army.mil)
Brief Description
In the commercial world, technological innovations often occur over a period of time, and can be traced back to a series of timely events that make a disruption, or leap ahead in the technology possible. For the U.S. military, it is often a change in doctrine that causes military research organizations to push for technology solutions to meet the needs of the new doctrine and adapt to emerging threats. A notable example is the development of self-contained, wireless patient simulators that operate without requiring a cumbersome rack of equipment. Army research and development personnel saw the need for patient simulators to be more mobile to support changing doctrine. Once Army research and development produced the first wireless patient simulator, all manikin manufacturers followed suit. The paper explores two capability gaps in medical training systems, Prolonged Casualty Care (PCC) and female trauma, and presents a case that it is time to reconsider medical modeling and simulation technologies to properly support training of these two areas.
Background
In the late 1990’s, the military led industry to reconsider the design of human patient simulators. Manikins at the time were extremely robust, but they were tethered to large racks of equipment, which limited their movement to just a few feet. The principles of Tactical Combat Casualty Care, or TCCC, require patients be moved to a safe location, out of the line of fire, as soon as possible (Butler, Hagmann, & Butler, 1996). Tethered manikins were forcing instructors to teach one thing, and trainees to practice another. The Army challenged industry to develop patient simulators that were not tethered to immobile racks of equipment, a challenge that resulted in the first Standalone Patient Simulator. Within a few years of this research and development project, all patient simulator companies were marketed as self-contained, wireless patient simulators. The Standalone Patient Simulator, and other commercial models that followed, were tailored specifically to military trauma, allowing trainees to treat the leading causes of battlefield death. More importantly, they allowed trainees to carry the manikin from the point of injury to a casualty collection point, load it in an ambulance, take it to a field surgical hospital, perform battlefield handoff, and continue treatment. Civilian emergency response mass casualty exercises can likewise simulate an active shooter casualty that can be treated at the scene, taken in an ambulance to a hospital, and treated in an emergency department.
The primary driver of the development of this technology was the emergence of TCCC principles. Developed by Special Forces in the late 1990s (Butler, Hagmann, & Butler, 1996), TCCC was soon adopted by conventional forces (Savage et al., 2011). TCCC is composed of three stages: Care Under Fire, Tactical Field Care, and Combat Casualty Evacuation Care (CASEVAC) (Butler, Hagmann, & Butler, 1996). While Care Under Fire can occur at the point of injury, a tenet of Tactical Field Care is that the medic and the casualty are no longer under enemy fire. Suppressing enemy fire is one method to ensure the medic and casualty are safe; moving the casualty to a “safe” location is another. During CASEVAC, care is still rendered.
A capability gap thus existed for training: manikins that could replicate battlefield trauma could only be moved a few feet from the equipment that controlled fluid exchanges and the manikin's physiology (e.g., simulated breathing and bleeding). As stated earlier, this capability gap drove the Army science and technology (S&T) community to develop the Standalone Patient Simulator.
Training to Treat Female Trauma
In 2015, then-Secretary of Defense, Ash Carter, removed gender restrictions on females serving in combat roles (U.S. Department of Defense, 2015). Even before Secretary Carter removed the restrictions, a 2014 study showed 12% of the U.S. veterans of operations in Iraq and Afghanistan were female (Rivera & Johnson, 2014). This created a capability gap in medical modeling and simulation. Unlike the capability gap that drove the Standalone Patient Simulator, the military was not teaching one thing while technology limited training to another. There simply was no capability to train trauma on a female patient simulator.
To further illustrate the need for realistic female trauma patient simulators, Cross et al. (2011) indicated mortality appeared higher for women than men in both Iraq and Afghanistan. While later research (e.g., Schauer et al. (2019)) disputed higher mortality rates for females, peacetime research indicates females should survive at a higher rate than men (e.g., Deitch et al. (2007)).
Following Secretary Carter’s removal of gender-based restrictions, the military’s medical modeling and simulation community began a multi-year S&T effort to develop realistic female trauma patient simulators and explore whether the lack of such simulators was a capability gap that could lead to more trauma-related deaths of females on the battlefield. The initial approach was a “Gender Retrofit Kit” (GRK) that made the patient simulator fielded at the Medical Simulation Training Centers more female in anatomical appearance, while not altering physiology. The GRK was tested in a variety of user tests (e.g., Mazzeo et al. (2018), Craig et al. (2022), Craig et al. (2022)) and was used in mentoring cadets over three years of capstone projects at the United States Military Academy to assess its utility and effectiveness. Two issues were evident in many of the tests: medics and non-medics alike hesitate to remove undergarments, a necessary step in treating an upper chest wound, and performance was consistently suboptimal when placing a chest seal over wounds that required partial placement over breast tissue. The GRK has since undergone operational testing and has been licensed by the major manikin manufacturer it fits.
In addition to the GRK, the Army led development of a full-fidelity patient simulator, designed to realistically simulate a female in both anatomy and physiology – not simply converting an existing male manikin. Measurements were based on a comprehensive 2012 anthropometric survey of Army personnel undertaken by the U.S. Army’s Soldier Center (Gordon et al., 2012). This manikin is designed for all critical TCCC tasks and procedures, in addition to some Prolonged Casualty Care procedures. The manikin has a full physiology engine, and condition deteriorates in the absence of treatment. In addition to the ability to place wounds in the upper chest, the manikin has an optional inguinal (groin) wound which can be set to bleed and requires removal of underpants to see and pack. This manikin likewise underwent a series of usability tests and is on schedule for operational testing in early 2024.
Prolonged Casualty Care
The nature of future conflicts is expected to change. The US may no longer be able to evacuate casualties quickly – the “golden hour” of medical treatment. Instead, a near-peer conflict in which casualties may need to remain with their operational units for longer periods of time is increasingly likely. Therefore, the concept of Prolonged Casualty Care, or PCC, is becoming more important (Aker, 2022). Medics may need to not only treat casualties at the point of injury but continue to treat them for an extended amount of time until friendly forces are able to reach them to evacuate casualties. Like TCCC, PCC has its roots in the Special Operations community. Called Prolonged Field Care, or PFC, the treatment guidelines were based on the necessity of a unit not risking providing opposing forces with information on its location.
Providing technology to train for PCC is quite complex. First, the element of time makes training difficult. Training a TCCC scenario, which may involve a short, simulated firefight or explosion, a few minutes of Care Under Fire, a few more minutes of Tactical Field Care, then preparing the casualty for evacuation, takes typically 30 minutes to an hour – certainly not a taxing requirement for a training day. PCC takes considerably more time. While doctrine does not set limits on what constitutes “prolonged,” a unit may need to maintain their casualty or casualties for days, perhaps while additional unit members are injured. Such a multi-day training exercise is difficult to fit into a unit’s training regimen.
Second, an injured casualty’s physiology will improve, or worsen, over time based on initial and on-going treatment. Most human patient systems (as well as virtual and extended reality training systems) rely on a human physiology engine to provide physiological feedback. Physiology engines model human physiology and run separately from the patient simulator (be it live or virtual). This allows developers of patient simulators to focus on what they do best and allow a validated physiology model to run in the background (Barnes, et al., 2020). Physiology engines, however, were originally designed to run in real time. To overcome the tyranny of time, physiology engines must receive an initial injury and treatment, and then allow time to pass at different speeds. Physiology engines should then be able to return to real-time to allow medics to read vitals and perform follow-on treatments, then speed up again.
Third, injuries will likewise improve or deteriorate over time. Simply applying a new piece of moulage provides a low-tech, inexpensive method to solve this problem. Virtual simulations can easily display a change in an injury. Thin film displays may also provide a method for human-worn or manikin-worn injuries.
Finally, PCC does not always equate to a field environment. Patients may be forced to stay longer in a Role 2 facility for longer than normal. Similar to nurses in an ICU, medics must be trained in how to properly care for a patient for extended periods of time. Current patient simulators, built to simulate and train point of injury and trauma, are not optimized to train injuries such as rashes, blisters, pressure ulcers (bedsores), and similar injuries caused by lying in a bed too long.
A simple solution to teaching PCC concepts is to present students with a patient simulator, moulaged and programmed to show an injury and physiological response. Students can then treat the simulator. Instructors can brief students on additional PCC concepts while another instructor re-programs the simulator and changes moulage. While effective for a “show-and-tell” demonstration, this approach will not work well for a mass casualty exercise. Furthermore, the breaks in training may limit simulating the stress of the operational environment (Cole et al., in press).
In a 2022 article, LTC Matthew Marsh and CPT Ryan Hampton analyzed the vital role Army medical training will have in future, large-scale combat operations, or LSCO (Marsh & Hampton, 2022). Marsh and Hampton reference a 2021 report from the Center for Army Lessons Learned explaining how larger numbers of casualties will overwhelm conventional medical evacuation capabilities. To combat this limitation, training must focus on building and rehearsing plans for casualty management, evacuation, and logistics to gain efficiency of movement and increase casualty survival rates. In their interview with U.S. Army Surgeon General, LTG Raymond Dingle confirms that “LSCO may result in a significant increase in casualties from what [the] DoD experienced... in Iraq and Afghanistan,” adding that operations must change “due to the sheer number of patients presented.” In a LSCO situation with numerous casualties, evacuation “may not be an option (Marsh & Hampton, 2022).” For these reasons, medical training and the patient simulations it requires must evolve to incorporate realistic rehearsal for triaging, treating, and/or moving dozens, even hundreds of patients at the division or company level. This will require a rethinking of current patient simulators, as scenarios can be expected to last well beyond the “Platinum 10 Minutes” (Bendall & Parsell, 2005) or even the “Golden Hour” timeframes.
The Path Forward
Female Trauma Manikins
The progression from tethered manikins to the first Standalone Patient Simulator was not easy. Industry pushed back on the necessity for an untethered manikin. Likewise, the initial user test of the first female patient simulator caused a senior medic instructor to wonder why the Army was paying for the development of a female manikin, since he considered the difference in male and female anatomy to be insignificant (a paraphrase of his actual quote). Medics having been trained for so long in point of injury care, and the concept of the “Platinum Ten Minutes” having become almost synonymous with the role of a medic, the concept of simply adapting current technologies rather than inventing new technologies will seem more attractive to industry.
The Standalone Patient Simulator was ultimately designed from the inside out. Reinventing the manikin meant first understanding what untethering would mean to the internals of the manikins. Developing a highly realistic female trauma patient simulator means so much more than making a manikin built to male standards look like a female by adding breasts and a wig and changing the appearance of the genitalia. The anatomical appearance is easy, but that is only the very beginning. Tissues behave and feel differently. Physiological differences are critical. Blood from a blood sweep in the groin of on a male could mean a potentially fatal wound, whereas on a female it might only mean menstruation.
Prolonged Casualty Care Training
The tyranny of time is the biggest issue to resolve in PCC training. How to compress a 48–72-hour PCC scenario into a 1–2-hour training period while capturing all the physiology changes, and changes to injury patterns, necessarily means changing how we think about training medics, as does considering issues involved with a casualty staying in the same bed in the same treatment facility for an extended period of time.
The Challenge
The Standalone Patient Simulator arose from the implementation of TCCC. Just as a human would not stay where injured but would be moved to a safe location, then to a casualty collection point, and ultimately to an evacuation vehicle, a human patient simulator should be capable of being moved. The need for a female trauma patient simulator does not come from any real change in doctrine, but from the fact the military did not push for a simulator that faithfully represented, in all aspects, 17% of its enlisted personnel. A system, or more likely systems, to train PCC is based on changing guidelines, and must consider the variety of ways it will be used and concepts it will train, all while overcoming the tyranny of time.
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