The military trauma surgeon has the seemingly contradictory task of preservation in an environment of destruction. History dictates the time and location of war, each occurrence with its share of casualties. Wounded warriors provide a service to their country and in their time of sacrifice improve a generation of surgeons. The price of lessons learned is severe and many times complete.

The Global War on Terrorism (GWOT) spanning over a decade including operations in Afghanistan and Iraq represents the longest continuous period of war in the US history. During this period much has been learned—providing advances in hemostasis, resuscitation, evacuation, damage control surgery, and transfusion strategies. Unfortunately, some lessons from previous conflicts had to be relearned such as the use of whole blood and hypotensive resuscitation. It is the duty of our generation to look back in time to glean from the experience of those before us and provide a surgical time capsule to be opened when needed.

Regardless of the nation, era, or location, combat casualty care has several qualities that separate it from its civilian counterpart. It tends to occur in austere, resource limited environments. The structures, equipment, supplies, and personnel are often required to be both mobile and few. By nature, ongoing hostile gunfire may threaten treatment activities for patient and provider alike. Additionally, the mechanisms of injury are disproportionately penetrating and blast associated.

Proximity drives much of modern combat casualty care. Warfighters are often in remote locations in today’s unconventional dispersed battlefield. With the purpose of decreasing evacuation times and distances first line surgical care is pushed further forward with a smaller footprint of facilities and personnel. Figure 52-1 is typical of this type of unit, in this case a forward surgical team (FST). At these locations damage control resuscitation and surgery is implemented with the goal of stabilization to the next higher levels of care. A chain of medical treatment is established from the point of injury to the final medical treatment facility (MTF) in the United States. Currently this chain of treatment and transport evacuation is typically completed within 72 hours.

Over the course of the following pages this chapter will endeavor to convey the current state of combat casualty care. The structure of prehospital interventions, en route care, facilities, and data management will be addressed. Special attention is devoted to recent discoveries and newly implemented practices. Throughout, there remains a close relationship between military and civilian trauma care, each constantly informing the other with expertise and innovation.

Benchmarking and Progress

The ability to evaluate outcomes of combat casualties is necessary to assess the capabilities of casualty care and determine areas for improvement. Trended over time these outcomes also provide a perspective of improvements and setbacks. Such information frames the foundation of evidenced based care. Wounded and injury rates require standardization in order to make comparisons, though such a reference has been lacking until the past decade. Holcomb et al developed a standardized measure which is referred to in Fig. 52-2 and expanded upon in the remainder of this section.¹

Wounded in Action and Killed in Action

Battlefield injuries (BI) are initially classified based on their survival to the first MTF. In the deployed setting this MTF is usually a battalion aid station, FST or combat support hospital (CSH) (see the section “Roles of Care” further). Those who do not survive the initial injury and transport are considered killed in action (KIA). Those who survive to the MTF are considered wounded in action (WIA). Those who return to duty (RTD) within 72 hours are typically not included in the final WIA figures. The gross number of killed and injured troops provides general information regarding the battle characteristics, initial care, and evacuation. As injury severity increases it is expected that the ratio of KIAs would increase. Likewise evacuation times and the effectiveness of first responder efforts can result in variations in the WIA/KIA ratio. Efforts to decrease the KIA rate include body and vehicle armor, field care advances, and decreased evacuation times.

Died of Wounds

The died of wounds (DOW) rate provides a measure of mortality after arrival at the MTF. Measured as a percentage, it is determined by the fraction of those WIA who do not survive (not including RTD). As the DOW rate includes only those who survive to the MTF, it is a useful measure of the treatment effectiveness at the MTF. Key to its use as a comparative measure is the exclusion of those patients who RTD. The inclusion or exclusion of RTD in the DOW rate calculation has been variable until recently standardized. Also, the expediency and efforts of the medical evacuation crew (MEDEVAC) may result in more patients with fatal injuries surviving to arrive at the MTF only to die shortly thereafter decreasing the KIA rate and increasing the DOW rate. Thus, advances at any point in the evacuation chain can affect measures elsewhere in the system.

Case Fatality Rate

The case fatality rate (CFR) provides another proportional measure of battlefield lethality. Deaths from both KIA and DOW are included. The denominator includes all those injured on the battlefield—KIAs and WIA (not excluding RTD). It is expressed alongside the other equations in Fig. 52-3. When used to compare scenarios with similar battlefield characteristics it can provide additional insights into the aggregate effectiveness of pre-MTF and post-MTF arrival casualty care.

Research comparing the current operations with prior conflicts has been limited due to variation in amount of data, how those data are recorded, and inconsistency of terminology. It became clear that a benchmarking measure was required to have more meaningful and standardized data collection and reporting at a systems level. The civilian methods for benchmarking and capturing data for analysis on a large scale are civilian trauma registries performed at local and regional levels, the National Trauma Data Bank and the Trauma Quality Improvement Program. The Department of Defense Trauma Registry (DoDTR) was created with these civilian models in mind. Since 2004 all comprehensive, standardized data are collected from the point of injury onward and maintained by the US Army Institute of Surgical Research.²

Injury Patterns

The improvised explosive device (IED) has become the characteristic weapon of the recent conflicts in Iraq and Afghanistan. The IED and the countermeasures to mitigate its effects have shaped the distribution of injuries sustained. This transition from gunshot wounds (GSWs) to blast injuries has been in evolution since the US Civil War.³ Other explosive devices, besides IEDs, and GSWs still remain a significant source of morbidity and mortality.

IEDs have become common in the current Global War on Terrorism and recent terrorist events. Increased adoption of their use has been driven by a combination of available materials and destructive power. While their forms vary widely they all share four essential components denoted by the acronym “PIES”; P-power source, I-initiator, E-explosive, and S-switch (Table 52-1).^4,5 Adjuncts, such as formed charges or fragments are often added. All items required for construction are readily available, making their creation easy and prevention problematic.

A common utilization of IEDs has been in the form of roadside bombs. As the recent conflicts progressed, efforts were made to decrease the high number of injuries sustained in high mobility multipurpose wheeled vehicles (HMMWVs). This spurred the development of the mine-resistant ambush protected (MRAP) vehicle with characteristic armor and a V-shaped hull to deflect blast energy (Fig. 52-4).

As coalition troops became less susceptible to roadside bombs with the advent of improved vehicle armor the use of IEDs shifted. “Dismounted” IEDs became more common, targeting soldiers on foot patrols. IEDs have also been used via a variety of delivery devices, to include vehicle (vehicle-borne IED or VBIED) and suicide bombers. This interplay between development of weapons and defenses has persisted throughout history.

The torso is particularly vulnerable to penetrating projectiles such as IED created fragments or firearm rounds. In response, modern body armor provides protection to this area (Fig. 52-5). The effectiveness of body armor used by the US military has changed the distribution of combat injuries. Areas without protection, such as the extremities, are the more common sites of injury. The increased use of explosive devices by insurgent forces described earlier has also evolved in response to weaknesses in armor coverage. A recent review of 5 years of injuries in Iraq and Afghanistan revealed the presence of extremity injuries in 51.9% of combat casualties, the vast majority of wounds (74.4%) were due to explosive devices.⁶

Education and Resources

Clinical Practice Guidelines

As initial surgical interventions for combat casualties occur over a wide variety of dispersed locations, the challenge of standardization and education increases. As a response, the joint theater trauma system (JTTS) has created a series of clinical practice guidelines (CPGs). These guidelines are modeled after civilian guidelines published by several of the national trauma associations. As of this writing there are over 40 evidence-based CPGs created by subject matter experts on a wide variety subjects (Table 52-2). The CPGs are updated routinely based on the available literature. The complete list is readily available at the USAISR Web site and is available as a portable device application.⁷

Tactical Combat Casualty Care

Warfighters who sustain injuries while under fire are treated with first-aid administered by self-aid, buddy aid, or a combat lifesaver. A combat lifesaver is a nonmedical team member who has enhanced first aid training. If the injured warfighter requires more advanced care, the combat medic or medical corpsman trained in tactical combat casualty care (TCCC) provides treatment.

TCCC was developed initially as a research project in the US Special Operations Command in the early 1990s. During this period, the trauma care was reviewed, revised, and then published in Military Medicine in 1996. Guidelines for TCCC are continually reviewed and revised by the Committee on TCCC (CoTCCC; Fig. 52-6). Trauma surgeons, emergency medicine physicians, combat medics, and corpsmen with combat deployment experience from all branches of the US military participate on the CoTCCC. TCCC is partnered with many other organizations such as prehospital trauma life support (PHTLS) and the US Army Institute of Surgical Research (USAISR). TCCC describes basic management plans for care under fire, tactical field care, and tactical evacuation care.

Care Under Fire

While providing care under fire, the medic or corpsman must (1) return fire and take cover, (2) direct or expect the casualty to remained engaged as a combatant if appropriate, (3) direct the casualty to move to cover and apply self-aid if able, (4) keep the casualty from sustaining additional wounds, (5) extricate casualties from burning vehicles or buildings and move them to places of safety and stop the burning process, (6) defer airway management until tactical field care phase, and (7) stop life-threatening external hemorrhage if tactically feasible with self-aid or tourniquets and move the casualty to cover.

Tactical Field Care

Once the injured warfighter is no longer under fire or has been moved to an area providing cover, the combat medic or corpsman then provides tactical field care. The evaluation and treatment of injuries in this phase of case is similar to the care provided by civilian prehospital care providers (with a few exceptions). Any warfighter with altered mental status must be disarmed of their weapons immediately. The usual airway and breathing assessment and treatments are carried out. In the assessment and treatment of bleeding, Combat Gauze (Celox Gauze or ChitoGauze if Combat Gauze is not available) is applied with a minimum of 3 minutes of direct pressure. If the medic or corpsman is unable to apply direct pressure or the bleeding cannot be controlled with direct pressure, the placement of a tourniquet is recommended. The administration of tranexamic acid (TXA) is recommended if the casualty is in hemorrhagic shock, receiving multiple transfusions, has one or more amputations, or penetrating torso injuries. For those casualties who are awake, alert, and have a palpable radial pulse; no intravenous fluids are administered. However, if the casualty is in hemorrhagic shock, resuscitation should be initiated with the following fluids (in order of preference): whole blood; plasma, RBC, and platelets in 1:1:1 ratio; plasma and RBC in 1:1 ratio; plasma or RBC alone; Hextend; crystalloid (Lactated Ringers or PlasmaLyte A). If there are no blood products available and crystalloids must be administered, only a 500-mL bolus is recommended followed by reassessment. If the casualty regains a palpable radial pulse or improved mental status, the fluid resuscitation is stopped. There are three options for providing analgesia to injured warfighters on the battlefield. For mild to moderate pain in the warfighter who is still able to fight acetaminophen and meloxicam (nonsteroidal anti-inflammatory drug) are given. For the casualty in moderate to severe pain who is not at risk for respiratory compromise or shock, oral fentanyl lozenges can be used. If the casualty is deemed to be in hemorrhagic shock or respiratory distress, ketamine is used for moderate or severe pain.^8,9

Role 1

The first medical care a warfighter receives is provided at Role 1. First-aid can be administered by nonmedical personnel on an individual level via self-aid or buddy aid. Each warfighter is issued an individual first-aid kit containing bandages, an advanced hemostatic dressing, a nasopharyngeal airway, a combat application tourniquet (Fig. 52-7), gloves, and tape. Combat lifesavers, nonmedical personnel with enhanced first-aid training, can provide additional care prior to arrival of the combat medic/corpsman. The combat medic/corpsman is trained in tactical combat casualty care (TCCC), which includes maintaining the airway, stopping bleeding, preventing shock, protecting wounds, and immobilizing fractures. The injured warfighter is then taken to the battalion aid station or Shock Trauma Platoon.

The BAS is similar for the US Army and US Marine Corps (USMC). At the BAS, a physician, physician assistant, or medic/corpsman makes triage, treatment, and evacuation decisions. The goal of treatment is to return to duty or to stabilize and allow for the evacuation to the next role of care. There is no surgical or patient holding capacity at Role 1.

The Shock Trauma Platoon is a small emergency medical unit that supports the Marine Expeditionary Force. Like the BAS, it has no surgical capacity; however the Shock Trauma Platoon is staffed by two emergency medicine physicians and can hold patients for up to 48 hours.

Role 2

At this role of care, basic primary care can be provided to warfighters. Optometry, dental care, combat and operational stress control, behavioral health, laboratory services, radiology services, and surgical capabilities are frequently available in a Role 2 facility. Each branch of the Armed Forces has slightly different organization and capabilities.

For the US Army, the Role 2 MTF is operated by the medical treatment platoon of medical companies. The medical company is assigned to support a brigade or division. Here, the warfighter is examined and evaluated. Those who can be treated and return to duty within 72 hours or require immediate damage control surgery to preserve life, limb, or eyesight are held for treatment. The warfighter can receive packed red blood cell transfusion, dental care, limited radiographic studies, clinical laboratory services, combat and operational stress control, and preventive medicine. The FST is a 20-person team with three general surgeons, one orthopedic surgeon, two nurse anesthetists, critical care nurses, surgical scrub technicians, and combat medics. It is designed to provide lifesaving resuscitative general and orthopedic surgery. An FST is deployed by ground, fixed or rotor wing aircraft, or via airborne operations. A fully supplied FST can operate continuously for 72 hours on two operating tables for a maximum of 30 cases. However, an FST is not designed or equipped for stand-alone operation and thus must rely on the medical company for logistical support (electricity, water, and fuel) and security. In the last few years of Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF), FSTs have been split to create two teams.

In the US Air Force (USAF), the Mobile Field Surgical Team (MFST) is comprised of five team members: a general surgeon, orthopedic surgeon, anesthetist, emergency medicine physician, and an operating room nurse or technician. Much like an FST, the MFST cannot participate in stand-alone operations and supports an aid station or flight line clinic. The 10-person Small Portable Expeditionary Aeromedical Rapid Response (SPEARR) team is a MFST with an additional three person Critical Care Air Transportation Team (CCATT) and two-person preventive medicine team. A SPEARR team is stand-alone capable for 7 days and can perform up to 10 surgeries in 48 hours. The SPEARR team is designed to provide care during the early phase of deployment and is highly mobile. The Expeditionary Medical Support (EMEDS) Basic team builds on the SPEARR team, with an additional 15 personnel. In addition to resuscitative surgery, EMEDS Basic can provide 24-hour sick call, dental care, and limited radiology and clinical laboratory services. There are four holding beds, two operating room tables, and three climate controlled tents. An EMEDS+10 facility has 6 additional holding beds for a total of 10 beds and 56 personnel but retains the same surgical capability as an EMEDS Basic.

For the US Navy (USN), Role 2 care consists of a Casualty Receiving and Treatment Ship (CRTS) or aircraft carrier battle group. The CRTS is part of a three-ship Amphibious Ready Group (ARG). With 45 ward beds, 4 operating rooms, and 17 intensive care unit (ICU) beds, the CRTS has a 176-person Fleet Surgical Team with 1 surgeon, 1 nurse anesthetist, 1 ICU nurse, 1 operating room nurse, 1 general medical officer, and 12 support staff. The CRTS can be augmented with an additional two orthopedic surgeons and one oral maxillofacial surgeon. Support services include frozen blood availability, radiology, and clinical laboratory capabilities. The CRTS can triage up to 50 patients and can only hold patients for 72 hours. The aircraft carrier battle group Role 2 assets do not typically support ground forces and are not casualty receiving ships. The 52 ward beds, three ICU beds, and single operating room are staffed by one surgeon and five additional medical officers.

The USMC Role 2 care consists of a surgical company that provides surgical care for one infantry regiment of the Marine Expeditionary Force. The surgical company is comprised of four Forward Resuscitative Surgical Systems (FRSS), four shock trauma platoons (Role 1 providers), and four en route care teams. The FRSS is the basic surgical capability module which can provide resuscitative surgery for 18 patients for 48 hours without resupply. Each FRSS has 2 surgeons, 1 anesthetist, 1 ICU nurse, 2 operating room technicians, and 2 corpsmen. Like the US Army FST, the FRSS is not a stand-alone unit and relies on the main unit for resupply and logistical support. The en route care team is comprised an ICU nurse and corpsman. They can transport and care for up to two critically injured warfighters (one requiring mechanical ventilation).

Role 3

The treatment available at this role of care encompasses the entire range of medical care to all categories of patients. The US Army Role 3 care platform is the CSH, which provides services for all categories of patients within theater. Two complete hospital companies provide resources, personnel, and equipment to care for up to 248 patients. Four ICUs and support staff can care for up to 48 critically ill patients and 10 wards with intermediate nursing care for up to 200 patients. In terms of surgical capability, the CSH has six operating room tables for general, orthopedic, thoracic, urological, gynecological, and oral maxillofacial surgery. In addition to surgical expertise, radiology, clinical laboratory, blood banking, psychiatry, public health, pharmacy, and nutrition support are usually available at this role of care. Medical teams, medical detachments, or hospital augmentation teams can augment capabilities of the CSH. Augmented services can include hemodialysis, clinical pathology, infectious disease, and head and neck surgery (neurological surgery, ophthalmology, and otolaryngology). Typically, only the head and neck surgery augmentation team is authorized a CT scanner.

In the USAF, Role 3 care consists of EMEDS+25 and the Air Force theater hospital. With 84 support personnel, two operating room tables, and 25 patient beds, EMEDS+25 can provide up to 20 operations in 48 hours. Additional modules with subspecialty capabilities such as otolaryngology, neurological surgery, ophthalmology, cardiothoracic, and vascular can be added to the EMEDS+25. The Air Force theater hospital provides the largest USAF surgery capability and critical care support in theater.

Role 3 care for the USN consists of expeditionary medical facilities and the USNS Mercy and USNS Comfort hospital ships. Each hospital ship has 12 operating rooms and 999 beds with 68 ICU, 20 postanesthesia care unit, 11 respiratory isolation, 400 intermediate care, and 500 minimal care beds. These minimal care beds are usually upper bunk beds reserved for patients ready to return to full duty; 273 officers and 943 enlisted personnel staff the ship with full clinical laboratory, radiology (with CT scanner), and blood banking services with frozen blood stores. The expeditionary medical facility has four operating rooms, 40 ICU and 110 ward beds. Clinical support services and surgical specialties for the expeditionary medical facility are similar to the US Army CSH.

Role 4

Medical centers outside the theater of operations at Landstuhl Regional Medical Center in Kaiserslautern, Germany, and other regional medical centers in the continental United States (Darnall Army Medical Center, Eisenhower Army Medical Center, Madigan Army Medical Center, San Antonio Military Medical Center, Womack Army Medical Center, William Beaumont Army Medical Center, and Walter Reed National Military Medical Center) provide Role 4 care.^10,11

Evacuation and transport of combat casualties is a multiservice and often multinational endeavor. The current doctrine of US military evacuation from the point of injury is centered on the “golden hour” concept. All battlefield injuries must be transported to the nearest Role 2 or Role 3 facility within 60 minutes. In the rare events that this does not occur, the case is formally reviewed for avoidable causes. Evacuation vehicles and surgical assets are geographically placed to meet these demands. Patients are transported from the point injury serially to higher echelons of care. An arrangement of various transport platforms has been assembled and a nonexhaustive list follows (Fig. 52-8).