Chapter 26 Combat and Casualty Care
For online-only figures, please go to www.expertconsult.com
The Beginnings of Military/Operational Medicine
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
Introduction
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
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
Combat Medicine Compared With Standard Civilian Prehospital Care
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
Scopes of Practice for Combat Lifesaver, Combat Medic
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.
Levels of Care and Capabilities
Military Health System Echelons of Care
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.)
Level V
Theater Trauma System
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
Joint Theater Trauma Registry
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
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).
Unique Aspects of Military Triage and Other Considerations
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
Clinical Applications of Lessons Learned
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.
FIGURE 26-5 Improved First Aid Kit (IFAK) components. MOLLE, Modular lightweight load-carrying equipment.
(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).
Hemostatic Agents and Tourniquets
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. http://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
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
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