03-Casualty care implications of large-scale combat operations

<h1>Casualty care implications of large-scale combat operations</h1>Remondelli, Mason H.; Remick, Kyle N. MD; Shackelford, Stacy A. MD; Gurney, Jennifer M. MD; Pamplin, Jeremy C.; Polk, Travis M. MD; Potter, Benjamin K. MD; Holt, Danielle B. MD<a href="https://journals.lww.com/jtrauma/fulltext/2023/08001/casualty_care_implications_of_large_scale_combat.26.aspx">Author Information</a>Journal of Trauma and Acute Care Surgery <a href="https://journals.lww.com/jtrauma/toc/2023/08001">95(2S):p S180-S184, August 2023.</a> | DOI: 10.1097/TA.0000000000004063 <img alt="IMG_256" src="/media/202408//1724856445.0830982.png" /><a id="en-media:image/jpeg:178c29321e242a7fa29915515e640693:none:none"></a><a href="https://journals.lww.com/_layouts/OAKS.Journals/ImageInfoService.svc/GetImagePptx/jtrauma/2023/08001/00026/ga">Export</a>While the prior two decades of counterinsurgency operations in the Middle East have resulted in critical advances in battlefield medicine with the lowest case fatality rate in history, the US military must prepare for future warfare involving peer or near-peer adversaries equipped with large, modern standing armies. The resulting operational environment, known as large-scale combat operations (LSCOs), will increase the scope of wounded service members to levels not seen since World War II (WWII). Lack of reliable air superiority will restrict evacuation and will preclude the ability to provide advanced surgical support within the “golden hour” for many, if not most of those wounded. In the last 20 years of conflict, the United States had the luxury of air superiority, rapid evacuation to surgical care, and robust resources, such as blood, medical personnel, and surgical teams. Injured service members will require prolonged far-forward care followed by delayed or lengthy evacuation to the next point of care. On the back end of trauma care, definitive care military facilities in the continental US will be overwhelmed by the sheer magnitude of required hospital bed capacity and will require a whole-nation approach that integrates civilian trauma systems. An integrated military-civilian trauma system was proposed in the 2016 NASEM Report, and while a small amount of progress has been made toward a national trauma system, there is still a long way to go.1Large-scale combat operation leverages multiple corps and divisions, encompassing 100,000 or more military personnel.2 Conflicts using advanced technology, such as long-range fires and advanced artillery will generate widespread destruction that may consume logistical resources within 72 hours to 96 hours, as well as demand large capacities for health services support and personnel replacement.2 Large-scale warfighter exercises estimate approximately 50,000 casualties (10,000 killed, 30,000 requiring evacuation, 10,000 returned to duty) with a daily estimate of up to 3,000 casualties in a battle of 100,000 soldiers.3 Success in LSCO leverages multidomain operations (MDOs) across land, maritime, air, space, and cyberspace, as well as consideration of the physical, informational, and human dimensions. To provide health services support in MDO, military medicine must identify casualties, provide combat casualty care, perform medical evacuation, and logistical resupply over prolonged distances with challenged communications and transportation capabilities. Medical MDOs (M2DO) synthesize casualty care across the evacuation spectrum to include direct patient care, logistics, patient monitoring devices, health records, patient transport and bed capacity, telemedicine, clinical practice guidelines, artificial intelligence, decision support, and registry data within joint operational defense communications and networks (Fig. 1). Medical performance optimization, leveraging the Department of Defense (DoD) Joint Trauma System's evidence-based methods to rapidly analyze casualty data to bring best clinical practices, resourcing, and training to the battlefield, will be crucial to increase survivability on the battlefield. Medical MDO also requires medical leader development to integrate health system support and force health protection concurrently within combat operations.Figure 1:M2DO involves the provision of health care on land, sea, in air, cyber, and space across the human, informational, and physical domains.By learning from the past, examining the present, and anticipating the future, this article will consider the implications of LSCO on combat casualty care during WWII, the current conflict in Ukraine, and a potential future conflict in Taiwan. Management of massive casualties, rapid clearance of the battlefield, medical evacuation, patient administration, triage, operating with constrained medical logistics, blood products, damage-control surgical capabilities, and definitive care represent key considerations that require further M2DO advances. This article seeks to further understand the requirements for M2DO to enhance force regeneration, casualty rehabilitation, and return to duty in a protracted, large-scale conflict.<h2>Past, Present, and Future Analyses of LSCO</h2><h3>LSCO in the Past: WWII</h3>World War II was the last conflict in which the US military fought a large-scale war against peer adversaries involving more than 50 countries and approximately 100 million service members. The peacetime medical force grew from approximately 1,200 doctors to more than 50,0000 by the war's end.4 The Invasion of Normandy, named Operation Overlord, best demonstrates the massive number of casualties that can be seen in LSCO.5 The sheer magnitude of patients (<a href="https://journals.lww.com/jtrauma/fulltext/2023/08001/casualty_care_implications_of_large_scale_combat.26.aspx&quot; \l &quot;T1">Table 1</a>), the transfer of casualties back to hospital ships from the beach, and the distance of travel to definitive care were some of the largest obstacles to care. Allied medical forces established 97,400 hospital beds in Great Britain, mobilized 8,000 doctors and 10,000 nurses, and gathered more than 800,000 pints of blood.4 Evacuation and treatment were conducted via 15 hospital ships and 50 Red Cross airplanes.4 The initial Invasion of Normandy resulted in an estimated 10,000 casualties with another 200,000 in the subsequent 85 days of Operation Overlord.6 More than 40 auxiliary surgical groups augmented far-forward casualty care at Normandy.7 The auxiliary surgical groups used during WWII were typically located within 30 miles of the front and were moved to the field and evacuation hospitals as needed rather than attached to them.8,9 The supplementation of fixed, large field hospitals away from the front lines with far-forward surgical support enabled immediate surgical stabilization before evacuation to higher levels of care. TABLE 1 - WWII Casualties During Major Events/Operations<table><tr><td>Historical Event</td><td>Duration, d</td><td>Casualties (KIA and WIA)</td><td>Average</td></tr><tr><td>Operation Overlord</td><td>~85</td><td>~209,000</td><td>2,459/d</td></tr><tr><td>Battle of the Bulge</td><td>~45</td><td>~75,000</td><td>1,666/d</td></tr><tr><td>Battle of Hürtgen Forest</td><td>~91</td><td>~34,000</td><td>373/d</td></tr><tr><td>Battle of Iwo Jima</td><td>~32</td><td>~26,000</td><td>814/d</td></tr><tr><td>Battle of Peleliu</td><td>~73</td><td>~11,000</td><td>145/d</td></tr><tr><td>Battle of Okinawa</td><td>~82</td><td>~50,000</td><td>609/d</td></tr></table>Adapted from the National World War II MuseumThe island-hopping campaigns in the Pacific theater revealed how extensive maritime distances and amphibious battles generated complex obstacles to medical command and control, far-forward surgical care, and evacuation capabilities.10 Interservice rivalries between the Navy and Army strained joint medical operations.11 The Battle of Iwo Jima resulted in an average of six casualties evacuated per minute within the first 8 hours of fighting.12 In the 6 days of fighting on Peleliu Island, the 7th Marine Regiment saw a 46% casualty rate.13 Surgeons had to weigh the risk-benefit of saving lives versus saving limbs. Mobile surgical groups and field hospitals were unable to debark onto the beachhead until it was fully secured, approximately six or more hours after the initial assault.10 The logistics of evacuating casualties under fire from enemy-held beaches resulted in prolonged delays. For instance, evacuating casualties from the beaches of Guadalcanal and New Georgia to an island with advanced surgical support took an estimated 72 to 84 hours.10,14 <h3>Current LSCO: Russian Invasion of Ukraine</h3>On 24 February 2022, the Russian Federation invaded Ukraine, a combat operation that has involved anti-tank missiles, thermobaric missile barrages, and naval bombardments which has escalated into intense urban ground combat, extensive drone attacks, and trench warfare. Combat casualty care challenges to providing life-saving damage control resuscitation and surgery have rapidly ensued as long-range munitions strike well beyond the front lines. The Russian Federation has been unrelenting in artillery usage targeting both military and civilian infrastructure including health care facilities, as well as electricity, water, gas, and internet services which have affected medical resupply.15Massive casualties from the Russo-Ukrainian war (<a href="https://journals.lww.com/jtrauma/fulltext/2023/08001/casualty_care_implications_of_large_scale_combat.26.aspx&quot; \l &quot;T2">Table 2</a>) present inherent challenges of casualty evacuation with the lack of air superiority and increased drone utilization restricting movement by air or ground. Medical communications are frequently interrupted and often hospitals receive no notice to prepare for MCE.16 Patients are being evacuated to hospitals by train carriages that have been refitted with hospital beds, generators for oxygen and medical devices, as well as capabilities for intensive care en-route.17 Polytrauma resulting from high-velocity penetrating vascular injuries, explosive injuries, traumatic brain injuries, and blast injuries have been the largest injury mechanisms reported.18 Incendiary munitions have resulted in increased burns and organophosphate poisoning that present difficulties for care due to the consumption of medical resources.16 More than 25% of patients present in hemorrhagic shock, however, the lack of power or the use of generators allows the detection of medical facilities limiting the storage and administration of blood products.16 Surgical teams operating close to the front risk do so at great personal risk suggesting the need for underground or hardened structures for medical hold. TABLE 2 - Russo-Ukraine War Casualty Numbers<table><tr><td>Breakdown</td><td>Duration, d</td><td>Casualties (KIA and WIA)</td><td>Average</td></tr><tr><td>Civilian casualties</td><td>~417</td><td>~23,000</td><td>54/d</td></tr><tr><td>Ukrainian Forces</td><td>~382</td><td>~120,000</td><td>314/d</td></tr><tr><td>Russian Forces</td><td>398</td><td>~200,000</td><td>502/d</td></tr></table><h3>Potential Future LSCO: PRC Invasion of Taiwan</h3>Predictions of future potential large-scale scenarios involving the invasion of Taiwan combine the difficulties of urban MCE care seen in the current Ukraine war with the challenges seen in the Pacific theater of WWII. A Chinese invasion of the island of Taiwan would likely result in casualties isolated and surrounded on the island as well as difficulties associated with amphibious operations and evacuation across the Pacific Ocean to definitive care. In a Center for Strategic and International Studies wargame of this potential conflict, personnel casualties averaged 6,960 during a 3-week conflict, with 3,200 killed in action (<a href="https://journals.lww.com/jtrauma/fulltext/2023/08001/casualty_care_implications_of_large_scale_combat.26.aspx&quot; \l &quot;T3">Table 3</a>).19 Winning against China would come at a high cost, resulting in immediate casualties unlike anything seen since WWII, with daily casualties on the order of 140 per day. TABLE 3 - Potential PRC-Taiwan Wargames Estimated Casualties<table><tr><td>Potential Event</td><td>Duration, d</td><td>Casualties (KIA and WIA)</td><td>Average</td></tr><tr><td>Invasion of Taiwan</td><td>7–21</td><td>~7,000</td><td>140/d</td></tr></table>In the Indo-Pacific, ships with medical capabilities will likely interface with the evacuation of casualties, prolonged casualty care, and damage-control resuscitation and surgery. While dedicated hospital ships provide robust capabilities, they also have limited maneuverability and represent potentially vulnerable targets. Wargaming suggests the United States alone will lose between 8 and 17 ships, demonstrating a need for rescue and nonhospital ships that can receive and hold patients in smaller harbors and travel vast maritime distances. Smaller, more agile medical ships that provide damage-control surgery face a bed capacity limitation. Medical hold and prolonged casualty care capabilities would likely be needed along the islands between Japan and Hawaii.<h2>CASUALTY CARE IMPLICATIONS OF LSCO</h2><h3>Massive Casualties, Medical Evacuation, and Prolonged Casualty Care</h3>As demonstrated in WWII, Ukraine-Russia, and PRC-Taiwan wargames, the immense rate at which casualties will be received sets apart LSCO from recent conflicts (Fig. 2). The improved case fatality rate seen in the wars in Korea, Vietnam, Iraq, and Afghanistan not only resulted from improvements in medical care but also the capacity for rapid medical transport.20 Large-scale combat operation presents obstacles in evacuation due to the sheer scale of a large geographic theater. Current evacuation platforms are limited by casualty capacity, available providers, and an ethical framework for order of evacuation. Rather than immediate evacuation by air, patient movement may become a prolonged process involving ground, sea transport, and ambulance transfer points. The long evacuation times to damage-control surgical capabilities will increase the need for medical personnel and en-route care providers to provide prolonged advanced emergency medical care as close to the front as possible. Figure 2:Past, present, and future predicted casualty rates. Comparing rates of casualties per day across past conflicts, the Russo-Ukraine war, and theoretical conflict with China in Taiwan.Patient transfer and administration are also limited by the lack of an automated system for patient condition, bed capacity, and health records during the evacuation process. Interventions are documented on a Tactical Combat Casualty Care card (DD Form 1380) and transferred via written or verbal communication, but ideally, this information would be captured digitally. The development of digital patient information represents a key component of M2DO that has been limited by the ability to universally adopt technical standards and materiel solutions.<h3>Triage, Medical Logistics, and Damage-Control Surgery</h3>High numbers of casualties demonstrate the need for quicker and simpler methods to triage. The scale of the MCE needs to be understood relative to available personnel and resources. This may require prioritizing casualties who can be returned to duty over the severity of injuries known as reverse triage, as well as integration of operational and logistical considerations described as situational triage.21,22 Straightforward approaches are needed for the triage of MCE that can quickly sort casualties into three categories for MCE: “ambulatory or dead” (don’t need immediate attention) and “stable or unstable” (need attention and need immediate attention) casualties.23 In the case of thousands of casualties, the entire scene will need to be secured and organized first, which will consume time that would have been used for the care of immediate life-threatening injuries. Systems of triage are contingent on the availability of skilled providers who have the clinical abilities to identify those with immediately life-threatening injuries who have a chance for survival compared with similar injuries with less chance for survival. This is truly complex decision-making and requires skills that take years to develop, underscoring the need for modernized decision support and triage tools. The use of blood near the point of injury represents a key component of medical logistics that can impact survival for those dying of hemorrhagic shock. In a study evaluating the criticality of the “golden hour,” Kotwal et al.24 determined that reaching a surgical facility in less than 1 hour reduced mortality in those most severely injured by 40%, but in reevaluation of this data, the early use of blood products was found to reduce mortality by 80%, twice the impact of evacuation time.25 Early blood product administration in LSCO can potentially overcome limitations in medical evacuation. The challenge, however, will be the delivery and storage of the correct blood components to the location most needed at the right time. Unmanned aerial vehicles have the potential to overcome the medical logistic gaps of blood product delivery within prehospital operating environments.26 The 2022 Project Crimson demonstrated successful drone-assisted delivery of blood and other medical products to the battlefield with storage in autonomous refrigeration units.27 The Ranger Regiment and Marine Corps have demonstrated the feasibility of person-to-person “walking blood bank” transfusion of low-titer O whole blood on the battlefield with conventional forces now looking to widely field.28 Freeze-dried plasma, which has been available to other militaries and certain US forces, has the advantages of room temperature storage and reconstitution with sterile water while demonstrating no differences in mortality or adverse events compared with fresh frozen plasma.29 In addition to blood product administration and resupply, control of hemorrhage via damage-control surgery remains critical to saving lives on the battlefield.30 In large-scale operations, austere surgical teams may be directly targeted and cannot be rapidly replaced on the battlefield.31 The previous practice of placing surgical teams on relatively secure forward operating bases and combat outposts during the wars in Afghanistan and Iraq was only feasible due to an established theater of operations. Austere surgical teams must remain mobile and maneuver with the operational force to “push forward” to care for casualties and then “jump back” to secure areas to minimize risk, potentially with large numbers of casualties which cannot be rapidly evacuated. The Army Forward Resuscitative Surgical Detachment doctrine includes this function, but with few exceptions, these teams have not trained or been used in this manner during the past two decades. A host of other hybrid surgical teams has been developed by all of the services, but these are not universally employed and doctrinal capability has not yet been written.32 <h3>Definitive Care</h3>The massive combat casualty numbers previously discussed will strain the care continuum, exceeding the capacity of the military health system and requiring integration within civilian trauma systems. Large theater hospitals seen in WWII represent easy targets and large numbers of dispersed beds will be required until patients can be evacuated out of the combat theater. The European and Pacific theaters each had more than 100,000 hospital beds with approximately half in the Mediterranean theater.33 The Army's current deployable hospitals have been restructured into modular hospital centers which consist of two field hospitals with a combined bed capacity of 240 beds with a total deployed inventory of approximately 4,000 beds.34 Reductions in deployed hospital beds will result in the need for patient evacuation to the United States and expansion of the federal hospital system. World War II required significant construction of hospitals with many from converted civilian buildings, such as hotels with the number of beds available totaling 153,000 general hospital beds and 101,000 station hospital beds.35 If current federal hospital beds were combined from the DoD, Department of Veterans Affairs, Department of Homeland Security, and Department of Health and Human Services, this would roughly represent 56,000 beds, clearly demonstrating a need for expansion to the civilian sector in the event of a large-scale conflict.36 As the COVID-19 pandemic has challenged “just-in-time” supply chains and hospital bed capacity, LSCO will require expansion planning for “just-in-case.” Following the 2017 US National Defense Authorization Act with the support of the US Pandemic and All Hazard Preparedness and Innovation Act (also known as the Mission Zero Act), the military services have expanded civilian partnerships which could be further integrated into a national casualty receiving system.37 Within Department of Health and Human Services, the National Disaster Medical System (NDMS) consists of trained personnel to deploy in the event of an MCE or other national emergency. Existing military-civilian partnerships could be expanded within the NDMS to form a national trauma care system as described in the NASEM report.1 In addition to the need for the rapid expansion of bed capacity, a medical draft is likely without the alignment of emergency medical personnel through the NDMS. The Selective Service System maintains a standby plan called the Health Care Personnel Delivery System which, in the event of a national emergency, would allow the draft of health care personnel including women between the ages of 20 years to 45 years.38 <h2>CONCLUSION</h2>Large-scale combat operations present unique challenges for medical support that must be planned for to not only save the most lives on the battlefield but to preserve the fighting strength by a skilled, competent, and force-multiplying deployed medical system. Improved techniques for managing MCE, delayed evacuation, prolonged field care, triage, logistical resupply, mobile damage-control resuscitation and surgery, and transfer to definitive care will require changes across the M2DO spectrum. Potential future conflicts with peer or near-peer militaries will require integration of the federal health care system with civilian trauma systems in a comprehensive NDMS to prevent the humanitarian crisis being seen with the Russo-Ukrainian war. A national trauma system that forms a comprehensive M2DO framework will best prepare the United States for responding to national emergencies and large-scale conflicts of the future.Adapted from the National World War II Museum