Chapter 26 Combat and Casualty Care
It is difficult to emphasize sufficiently the importance of initial treatment on the battlefield. What the wounded soldier does in his own behalf, or what his infantry colleagues do for him; and what the company aidman does for a traumatic amputation or gaping wound of the chest, in the thick of battle, in dust and heat or in blowing snow—on these simple procedures depend life and death. … A slight improvement in the skill and judgment of the company aidman will save … more human lives than will the attainment of 100 percent perfection in the surgical hospital.
Wilderness Medicine is Combat Medicine with the exception of heavy artillery and aerial bombardment. Both are charged with the delivery of medicine/lifesaving interventions in less than optimal environments, with minimal equipment, and varying evacuation times.
Wilderness medicine practitioners and disaster, humanitarian, and nongovernmental organization workers venture into environments that are complex, often with unique geography, political/governmental systems (or lack thereof), and unfamiliar cultures; economic and resource situations may be constrained or desperate. These areas may be involved in conflict, so it is beneficial to have an understanding of the nature of combat casualty care.
The first “operational wilderness medicine” courses and training were created centuries ago by military forces. Operational and wilderness medicine requirements have shared a long and symbiotic relationship with exchange of information, lessons learned, and equipment between the military and those physicians and responders willing and able to work in austere environments. Much of the knowledge, both remotely and recently, has benefited emergency care in general and wilderness medicine in particular. Much of the equipment and expertise now used by the military have resulted from improvements and refinement of wilderness medicine professionals. One of the first wilderness medicine experts to document wilderness medicine knowledge was Ibn Al Jazzar (circa AD 895-979) a physician from the Medical School of Kairouan in what is now Tunisia, once known as Carthage, the home of Hannibal (circa 200 BC). He wrote the then landmark wilderness medicine manuscript, Zad El Mousa Fir-Wa Qaout El Hadhir (Provisions for a Voyager Traveling Afar and for the Day’s Subsistence).56
The word for healer in ancient Greek was iatros, meaning remover of arrows. Whether removing arrows in ancient Greece or shrapnel in the 21st century, the unfortunate reality of conflict as part of the human condition requires health care providers to be involved in operational and military medicine. Since the beginning of recorded history, advice for medical response to be applied during conflict has come from those often noted for medical progress unrelated to conflict. Hippocrates (460-370 BC) is known as the Father of Medicine and for the concept, “First, do no harm.” He also gave the advice that “He who would become a surgeon should join the army and follow it.”
Early accounts of medicine in war came from the classic literature, such as Homer’s The Iliad and Virgil’s The Aeneid. The Romans learned from these wars and trained medics (medici vulnerarii); each soldier carried his own bandages, which is similar to the Improved First Aid Kit (IFAK) carried today by soldiers and wilderness trekkers. In these accounts, medicine was rudimentary. Medical intervention concentrated on basic issues of bleeding, infection, and injury. These were the leading early killers in war though the ages and remain so to this day.
In ancient times any significant injury was likely to result in death. In the Revolutionary War, lethality of combat injury was 42%. In the Civil War, the combat mortality rate was 33% for persons wounded; this decrease was due to improvements made in evacuation from the field with an ambulance corps and surgical care closer to the field. Even with the horrors of chemical munitions and trench warfare, World War I showed a decrease in war injury deaths to 21%. Great strides were made in World War II, including antibiotics and blood/plasma replacement; however, the combat mortality rate remained high at 30%. Korea moved Mobile Army Surgical Hospitals to the front and was the first conflict to routinely use air transport to get injured soldiers to the surgeons. The Korean conflict mortality fell to 25%. Vietnam further emphasized quick evacuation to combat hospitals, but the mortality rate remained steady at 24%.56 In Vietnam, fewer than 3% died after arrival at a combat hospital, attributed to meaningful medical interventions being made earlier.28,29,34 Most deaths were due to hemorrhage and airway/breathing compromise. Desert Storm in 1991, with a short but very intense combat phase, recorded 159 deaths from 626 total traumatic injuries, for a mortality rate of 25%. Military medical leadership studied previous lessons and created a better medical field response. The rates of mortality in the current conflicts of Operation Iraqi Freedom and Operation Enduring Freedom are the lowest seen in the history of conflict. Combat lifesavers (first responders) and then combat medics are at the scene immediately and buy time for injured soldiers. The likelihood of coming home is over 90%24,28,29,34,40 (Table 26-1).
In addition, disease, nonbattle injury (DNBI) has been a constant concern for the field surgeon and medic. The outcome of many conflicts has been determined by DNBI. Athens fell to Sparta in 430 BC as a result of an unknown communicable disease. DNBI affecting the outcome of conflict played out again in the trench warfare of World War I, and DNBI was deadly even in the same region of Gallipoli where the British and Australians lost many soldiers to dysentery and other nonbattle injuries.33 In the U.S. Civil War, for every death due to trauma, there were three deaths due to DNBI and starvation. In the Russian-Afghan war over the course of 10 years, the war’s outcome was influenced greatly by disease; some contend that Russia was “beaten by the bugs.”37
Combat by its very nature is a chaotic, dynamic, and unpredictable environment in which military medicine must function well to save lives. The methods and technologic advances used to kill and maim have increased the numbers of injured and the seriousness of the injuries. The nature of war has become less focused on armed conflict between sovereign nations fought by professional militaries and become an undertaking of insurgents, child soldiers, and terrorists. Battlefields often have “no front lines,” and conflict is more dangerous for soldiers, as well as deliberately targeted noncombatant civilians; military medical providers are using new skills to care for these patients.
Forward military medicine, performed before reaching combat support hospitals (CSHs), shares attributes with wilderness medicine. These include minimal equipment, harsh climates, remote and austere settings, and sometimes primal conditions. In militaries of the past, operational and wilderness medicine were taught after initial training as “on-the-job training.” Today they are primary medical training and education.
Austere conditions typically connote an image of uncivilized remoteness, but they are also found in large populated areas where medical conditions may be impacted by armed conflict, supply shortages, bad weather, and impassable evacuation routes. For persons who deliver prehospital care on the battlefield, in disaster or humanitarian situations, whether urban or rural, working in the “wilderness” is the norm, not the exception.
Regardless of environment, combat units within a battle space require medical capability. This capability is also used for injured civilians and forces that have laid down their arms. As strong as military medicine is as a force multiplier, it is also often used as a national engagement tool to shorten conflict, because medicine’s center of gravity and power is science and humanity, not geography, religion, or politics. When used in this manner, medicine may enhance progress toward peace.60
This chapter reviews a few lessons learned from military medicine, with the battlefield as the construct. The intent is to provide operational civilian health care providers an understanding of unique military medical capabilities, the continuum of care, and unique battlefield injuries, as well as describe some of the medical treatments and evacuation issues from the point of wounding to definitive medical care. We thank the hard work and sacrifice of military medical providers throughout history who have advanced medicine on every front and in many cases have forged a path for others to follow.
In conflict environments, completion of the mission and preserving one’s own forces take precedence. Medicine has a place in the tactical environment but is relegated to a secondary role at certain points. Mission-focused combat care is divided into three distinct classifications designed to support the mission: decrease loss of life using principles of triage, take care of immediate life threats with simple interventions of proved benefit, and save as many lives as possible through rapid evacuation. These phases of care do not normally rely on a complete assessment, physical examination or evaluation of past medical history, as might be expected in a secure location in a routine field emergency situation.17,18
The first phase of care, also known as care under fire, can be thought of as any event in which one is called on to render aid in an uncovered, unsecure, or potentially life-threatening situation. One cannot and should not “treat in the street” in a hostile environment. The first action will be to return fire and take cover (or take cover and return fire if more appropriate). There are many reflexive and simultaneous actions that will take place in this phase if the soldiers have been trained and drilled to an adequate degree of fine muscle memory. If one is able to provide care in this phase, the clinical intervention is likely to be only the most basic, such as moving the patient to a covered area to avoid further injury or placing a tourniquet. The usual protocols for ABCs (airway, breathing, circulation) may be reordered to CAB in order to focus on the interventions most likely to have the greatest impact on outcome in the working time frame.63
Care under fire may simply determine whether or not a person is still alive. Mortal wounds or conditions such as an unresponsive patient without a carotid pulse are circumstances in which cardiopulmonary resuscitation would not be performed. After this phase is over, it is important to not forget security issues. These are easily overlooked because of euphoria that may result from the relief of surviving, or the need to begin to care for one’s comrades.18,63
Field medics have long noted that one of their most critical first actions is to provide a confident demeanor. If the casualty is alert and responsive, the medic asks, “Where are you hurt?” and uses words and body language to let the victim know, “I’ve got you, and we’re going to get you out of here.” This is important because the casualty will be trying to determine his or her survivability and prognosis from the medic’s reaction. Major Shon Compton (U.S. Army physician assistant) teaches, “If the mind quits or doubts its chances; the body soon follows …”
The next phase of care is casualty tactical evacuation, in which the patient is stabilized and transported to a more definitive level of care. Evacuation platforms most often are “nonstandard” and nonmedical vehicles that are quickly drafted into use for critical casualty evacuation (CASEVAC).
Injured soldiers are unlikely to see a physician at the point of wounding. The Army has taken the civilian trauma system lessons of the “golden hour” to the next stage in what it calls the “platinum 10 minutes,” using combat lifesavers and combat medics to provide initial response on the battlefield. Many military emergency physicians note that in that first few minutes, there should be no qualitative difference in the response to traumatic injury between the medic and the physician. Given the same aid bag, the same set of circumstances, and the same patient, the expectation is that the same immediate lifesaving interventions will be made.63
Combat lifesavers are first responders that are sometimes called the “battle buddy” of the medic. They buy time for the patient after the initial trauma. Their primary military occupational specialty may be that of infantry, aviation, maintenance, or other military nonmedical specialty, but after the situation is secured, they offer an extra set of hands for the medic. In addition to basic first aid, they are able to provide such skills as to deploy nasopharyngeal airways, apply tourniquets, or perform needle chest decompression for breathing difficulty after a penetrating wound to the chest (Figure 26-1).5 They do not, however, initiate intravenous (IV) lines or perform certain other advanced skills.
The combat medic is also known by the designation 68W (68 Whiskey). The scope of practice of the combat medic is most analogous to an EMT-Intermediate, with some special skills training in combat operational medicine based on the security, sick call, and unit issues with which the medic must deal. Additional airway skills include use of an adjunct such as a Combitube or King LT device and surgical cricothyrotomy (see Figure 26-1). The 68W is also taught the skills of needle chest decompression and chest tube placement. The 68W has the ability, with special training, to place an IV or intraosseous line and in certain cases administer blood products. The 68W has additional training in management of shock, including resuscitation from hypotension and prevention of hypothermia. Because closed head injury, burns, and stress reactions are prevalent wounds of the Iraq and Afghanistan conflicts, combat medics are entrusted with the initial evaluations of these problems. If the patient cannot be evacuated in a timely fashion, the combat medic may initiate protracted care, to include the placement of a nasogastric tube and urinary catheter. Combat medics also have the capacity to perform limited primary care, using protocols for minor sick call problems, and assist with monitoring for DNBI. They are given training in international humanitarian law (Geneva Law) focused on the rights, duties, and responsibilities of combat medics in areas of armed conflict, as well as caring for detainees.
The continuum of care in the military extends from the point of wounding to a battalion aid station (BAS), usually staffed by a physician assistant and/or physician, to the forward surgical team (FST) to the CSH (Figure 26-2).26 At each point of care, the level of surgical and holding capability increases. Military medical planning includes support at each of these levels.3,27,31,54
FIGURE 26-2 Taxonomy continuum of health care capabilities.
(From Defense Medical Readiness Training Institute: Joint operations medical managers course guide, San Antonio, Tex, 2009.)
The first medical care a soldier receives occurs at Level I, which may begin at the point of wounding. Initially, these first responder actions are provided by soldiers with combat lifesaver training, and later with assistance from the combat medic. If the service member is transported to a BAS, care is augmented by a senior medic or physician assistant. Level I initiates triage, patient collection, resuscitative care, and medical evacuation to higher levels of care. If the injuries or illness are minor, treatment is given and the disposition is “return to duty.” If the care required is more than minor, the patient is evacuated to a Level II or Level III facility. The decision is made based on the security situation, distance, and nature of the injuries. The civilian equivalent is similar to a first responder ambulance squad with advanced skills.
Level II is broken down into Levels IIA and IIB. Level IIA is an expanded care hub for the BAS, called an area support medical battalion (ASMB); this is similar to an urgent care clinic. This level of care duplicates Level I and augments services, with limited dental, laboratory, optometry, preventive medicine, health service logistics, mental health services, and patient-holding capabilities. The ASMB can further evaluate a casualty to determine if evacuation to a CSH (Level III) is warranted. In remote locations, Level II facilities are often teamed with an FST, also designated as Level IIB, to provide initial damage control surgery. The FST has an orthopedic surgeon, two or three general surgeons, two anesthetists, and critical care nursing capability. It is configured to be able to complete 10 major surgeries per day. Level IIB is similar to an emergency department with emergency surgical services.
Level III may be a CSH, a hospital ship, or Air Force facility. These facilities are in the combat zone and are analogous to regional trauma centers, with a full complement of medical and surgical services. There are intensive care and patient wards. These facilities are modular and can expand from 44 to 248 beds. If the patient requiring rehabilitation or extended treatment can be evacuated in less than 48 hours, or will have a prolonged recovery time, he or she is evacuated out of the theater. Local national civilian patients are not evacuated out of the theater, and civilian care may require extended hospitalization and rehabilitation that was not initially planned.
The backstop of theater military care is the regional trauma medical center. This facility is within the theater, but on the evacuation pathway out of the combat zone. Definitive care, rehabilitation, and medical specialty services are available. The average stay is short for patients not expected to return to duty. These patients are further stabilized and evacuated out of theater for continued care at a Level V facility.
Definitive care describes Level V (primarily continental United States/CONUS) care. The Department of Defense and U.S. Department of Veterans Affairs hospitals provide this care. There are mechanisms to increase bed space using civilian hospitals in the National Disaster Medical System if this is vital to the effort.
Medical planning considerations loom large in the military because of the effects of practicing in an area of armed conflict often exacerbated by austerity of the environment itself. At one time an afterthought, military medical planning is now routinely considered at mission planning events. As for any wilderness medicine expedition, the specific characteristics of military health service support are determined by the mission, the threat, intelligence, anticipated number of patients, duration of the operation, the theater patient movement policy, available lift, and hospitalization and movement requirements. Military medical planners are expected to have an understanding of all the areas below:
Much of the improvement in survival rates in the Afghanistan and Iraq conflicts is directly attributable to implementation of a trauma system. In both military and civilian populations, large numbers of patient requiring treatment for trauma or illness are best served through a “system approach.” The best systems have a designated trauma system director who is responsible for data acquisition, critical review of collected records, development of medical policy and practice guidelines, and ongoing evaluation of medical resources utilization, including staffing.37
The Joint Theater Trauma Registry (Figure 26-3) is a key component of the Joint Theater Trauma System and was implemented in November 2004. As would any civilian trauma system, it collects the usual demographic and mechanism of injury data points. In addition, it collects information on unique transportation solutions, protective gear, service affiliation of the injured, and some unique aspects of conflict injuries (e.g., chemical, nuclear). This information has been analyzed extensively to develop and improve clinical practice guidelines, protective measures, medical and nonmedical training and best practices for patient care from the prehospital resuscitation, to damage control surgery, through rehabilitative care. The data have a very high fidelity in the fixed facilities but are less complete directly from the field.20,15,16,30
Field collection of information is more difficult to obtain due to communications problems, the chaotic and insecure environments inherent in combat operations, and initial care and evacuation by nonmedical responders. The military recognizes field collection of data as a critical link in combat care and is exploring many areas for improvement, if not full resolution of field data collection issues. The preliminary findings are the same as those found in civilian trauma systems; the solution needs to be simple, lightweight, fast, and easy to append to patient records.
The military has experimented with the Battlefield Medical Information System–Tactical (BMIST), an electronic data collection system. It is still the goal to use an electronic patient care recorder. Though relatively lightweight, the BMIST weighs 11.1 to 14.1 oz; every item in a combat medic’s aid bag increases difficulty in mobility and decreases treatment items. Currently, as a fail-safe method, a simple tactical combat casualty care (TCCC; also referred to as TC3 in other venues) card (Form DA 7656) is used and carried in the soldier’s IFAK. If the soldier is injured, this card is completed as best possible and moves with the patient to the treatment facility, where it is able to be scanned into the record. It is a better method of recording trauma data than was the previous field medical card (Figure 26-4).
As in civilian mass casualty situations, triage attempts to provide the greatest good for the greatest number of victims. In most cases, military triage categories mirror those for civilians: immediate, delayed, minimal, expectant. In military triage situations, the security situation is often grim, transportation may be delayed, and the triage category of wounded soldiers, who in a less dire situation might have a survivable injury, becomes “expectant.” In addition, the military trains for scenarios involving chemical, nuclear, and radiologic incidents to practice continued combat effectiveness. Triage and treatment may be delayed because of mission requirements. The apportionment of resources may be based on the need for mission success.
An interesting illustration of the need for continued combat effectiveness was described in World War II, where penicillin was first used extensively for wound infections. Penicillin was very effective in the treatment of sexually transmitted diseases (STDs), also seen in the military population. Because of its limited availability, penicillin was rationed and at times used first for those soldiers with sexually transmitted diseases rather than for the badly wounded, to keep the fighting forces at the front.53
Military triage has a component related to international humanitarian law. Soldiers who have laid down their weapons are offered the same opportunity in triage for care and treatment of their combat-related injuries. Triage for persons experiencing an emotional stress reaction, with or without wounding, require disarming before care can proceed.
Soldier Medical First Aid Kits (Figures 26-5 to 26-7) and Warrior Aid and Litter Kit
Improved survival rates in the current conflicts have been evaluated to search for further improvements. The reasons given for the 90% survival, even with increased lethality of wounding agents, are improved personal protective equipment, adherence to TCCC precepts, faster evacuation, and better-trained medics. The IFAK (see Figure 26-5) was developed based on the continuous review of injuries and is carried by every deployed soldier. It contains the essential items to address the major causes of preventable combat death: compressible hemorrhage, airway compromise, and tension pneumothorax. The IFAK contains a combat application tourniquet (CAT), kaolin-impregnated rolled gauze (Combat Gauze) that promotes hemorrhage control, 15.2-cm (6-inch) compression dressing (Israeli Trauma Bandage), nasopharyngeal airway, and 8.9-cm (3.5-inch) 14-gauge IV catheter for needle chest decompression. Hemorrhage is the leading cause of combat death. Interestingly, combat injuries have remained relatively similar in distribution since the Civil War; extremity injuries are the most common.
(From Army Medical Department Center and School: Briefing on Combat Equipment, 2007.)
FIGURE 26-6 World War II aid bag.
(From Army Medical Department Center and School: Briefing on Combat Equipment, 2007.)
FIGURE 26-7 M5 Vietnam aid bag. IV, Intravenous.
(From Army Medical Department Center and School: Briefing on Combat Equipment, 2007.)
A Warrior Aid and Litter Kit (Figure 26-8) is carried on vehicles, although it can also be easily dismounted and carried via shoulder straps to the point of wounding. The additional equipment increases a unit’s capabilities to provide self-aid/buddy-aid for multiple casualties and interventions for the three leading causes of death on the battlefield. Furthermore, it provides a military squad the ability to evacuate a nonambulatory casualty (folding litter) and increases survivability during dispersed operations (i.e., improvised explosive device [IED]/rocket-propelled grenade [RPG] attack on convoy).
The U.S. Army Institute of Surgical Research in San Antonio, Texas, finds that one-half of those injured in combat suffer “potentially survivable” wounds. Eighty percent of these are hemorrhage. In these bleeding events, 30% are in the extremities and “compressible,” where a tourniquet can be used to stop bleeding; 20% are in the neck, groin, axillae, or areas where a tourniquet cannot be used, but pressure can be applied to stop bleeding; and thorax or abdominal account for the remaining 50%, where surgical intervention is necessary.8,20,23
Jean Louis Petit, a French surgeon, developed a screw device in 1718. He coined the term tourniquet from tourner (to turn).64 The earliest known usage of a tourniquet dates back to 199 BC. Tourniquets were used by the Romans to control bleeding, especially during amputations. These tourniquets were narrow straps made of bronze covered with leather (Figure 26-9). These look remarkably similar to the CAT (Figure 26-10) used today.
FIGURE 26-9 Roman tourniquet.
(Courtesy Science Museum, London. www.sciencemuseum.org.uk/broughttolife/objects/display.aspx?id=4304.)
The CAT was selected after extensive testing and research. Other methods, such as a triangular bandage and sticks, can be used if a CAT is unavailable. The imperative is to occlude the distal pulse. It may take multiple tourniquets to accomplish obliteration of the pulse. Do not remove previously applied tourniquets if bleeding continues; tighten the tourniquet further if possible, or apply another tourniquet proximal to the first.63
TCCC teaches to attempt to control all sources of bleeding and consider and assess for any bleeding not immediately detectable. The TCCC protocol for life-threatening compressible external hemorrhage or amputation is tourniquet application. The tourniquet is placed on the skin 5.1 to 7.6 cm (2 to 3 inches) above the wound. For neck, groin, and axilla hemorrhage, Combat Gauze is used. It is packed in the wound, and direct pressure is applied for at least 3 minutes. Then, a pressure dressing is placed over the wound site if possible. For anatomic reasons, a pressure dressing may have to be innovative. It is impossible to circle the neck with a pressure dressing because the blood supply to the brain and airway will be disrupted.
A bandage that stops bleeding has been sought for centuries. Combat Gauze, which is a kaolin-impregnated Kerlix gauze, is the best hemostatic dressing at this time. Other agents have been reviewed and/or used but had drawbacks. Factor concentrators, such as QuikClot, that removed water from blood, created a significant exothermic reaction, were difficult to use in some environments, and were difficult to wash out of wounds. WoundStat used concentrated clotting factors without a significant increase in temperature, but caused some tissue damage and embolic episodes. Mucoadhesive vehicles, such as HemCon, Chitoflex, TraumaStat, and Celox, were made of shrimp exoskeletons. Although tissue damage was not seen, the hemostatic properties were not as robust as those seen with Combat Gauze. Combat Gauze is a procoagulant supplement that uses gauze impregnated with Kaolin (active agent is aluminum silicate) and is the hemostatic dressing issued to the U.S. military for combat use. In the future, fibrin dressings and spray-on sealants may become available.1,13,22,44–46
Combat Gauze may be used after the initial application of a tourniquet has stopped bleeding or if a tourniquet is not essential on inspection of the wound after the care under fire phase. It is vital to continually monitor bleeding if a tourniquet is placed or if other techniques are used, because these may become dislodged or the patient may start to bleed after fluids are replenished or the patient is warmed. Hypotensive resuscitation to avoid normalization of blood pressure and “blowing the clot” until surgical control is achieved is a key principle. Before releasing any tourniquet on a casualty who has been resuscitated for hemorrhagic shock, to ensure a positive response to resuscitation efforts, one should have applied a pressure dressing and be ready to reapply the tourniquet.
Tourniquets cause ischemia in the treated extremity. Release of a well-placed and functioning tourniquet after several hours releases lactic acid and potassium generated by anaerobic metabolism and cell injury. Before removal of a tourniquet that has been in place for any significant period of time, make sure the patient is well hydrated and as fully resuscitated as is reasonably possible, and consider adding 50 mEq of sodium bicarbonate to a liter of IV fluid for administration. Release the tourniquet slowly. If cardiac arrhythmias occur, reapply the tourniquet and wait to remove it until after further fluid resuscitation and sodium bicarbonate is administered. If the limb is “dead,” the overriding tenet is “life over limb.” Consider a fasciotomy (four compartment) in any lower extremity with extensive tourniquet time (over 2 hours).10
Control of bleeding is paramount in combat care. Adequate bleeding control may turn an “immediate” category patient into a “delayed” category patient, able to wait for secure transport. Tourniquets and hemostatic agents (QuikClot Combat Gauze) are the current best methods of bleeding control. Blind attempts at clamping vessels in bleeding wounds cause more damage than good and should be avoided. Bandages should be inspected frequently because they can hide continued bleeding.