Tactical Combat Casualty Care and Wilderness Medicine




Tactical Combat Casualty Care (TCCC) is a set of evidence-based, best-practice prehospital trauma care guidelines customized for use on the battlefield. Military units that have trained all of their unit members in TCCC have now documented the lowest incidence of preventable deaths in the history of modern warfare and TCCC is now the standard for battlefield trauma care in the US Military. TCCC and wilderness medicine share the goal of optimizing care for patients with trauma in austere environments that impose significant challenges in both equipment and evacuation capability. This article reviews the current battlefield trauma care recommendations in TCCC and discusses their applicability to the wilderness setting.


Key points








  • The Joint Trauma System helped the US military achieve unprecedented success in casualty survival during the wars in Afghanistan and Iraq.



  • Tactical Combat Casualty Care (TCCC) is the prehospital component of the Joint Trauma System.



  • Since most combat fatalities occur before the casualty reaches the care of a surgeon, TCCC plays a key role in ensuring that casualties have a maximal chance of survival.



  • The realization that extremity hemorrhage, a leading cause of preventable death on the battlefield, could be effectively and safely addressed with limb tourniquets was the primary driving factor for the Special Operations medical research effort that gave rise to TCCC.



  • Organizations advocating for the translation of TCCC concepts to the civilian sector include the Wilderness Medical Society, the National Association of Emergency Medical Technicians, the American College of Surgeons’ Hartford Consensus working group, the White House Stop the Bleed campaign, and the Committee on Tactical Emergency Casualty Care.






Introduction


In 1992, the Naval Special Warfare Biomedical Research and Development program undertook a review of battlefield trauma care. The primary driver for this research effort was the realization that, although extremity hemorrhage was a leading cause of preventable death in combat casualties and tourniquets could be applied safely for short periods, tourniquet use was universally disparaged in both civilian and military prehospital trauma care. A thorough review of battlefield trauma care recommendations at the time resulted in the development of the first set of Tactical Combat Casualty Care (TCCC) Guidelines, a set of evidence-based, best-practice trauma care guidelines designed specifically for use on the battlefield, which were published in Military Medicine in 1996. The Wilderness Medical Society (WMS) assisted in reviewing the TCCC recommendations, reevaluating the interpretation of the available evidence that supported these recommendations, and discussing their implications for the battlefield and other austere environments.


After 2001, the lessons learned from the battlefields of Iraq and Afghanistan allowed continuous refinement of the TCCC Guidelines through the efforts of the Committee on Tactical Combat Casualty Care (CoTCCC). Importantly, combat medics, corpsmen, and pararescuemen (PJs) have consistently been a strong presence in the CoTCCC.


Now, in 2016, TCCC has been well-documented to have played a major role in achieving the highest casualty survival rate in the history of modern warfare in military units that train all of their members in TCCC.


TCCC is presently the standard for battlefield trauma care in the US Military and for many allied nations. CoTCCC members work closely with civilian trauma colleagues in the Hartford Consensus effort and the White House Stop the Bleed campaign to translate trauma care lessons learned on the battlefield to lives saved at home. In cooperation with the National Association of Emergency Medical Technicians (NAEMT), the CoTCCC has helped to develop TCCC-based trauma courses to assist in training civilian emergency medical services systems, fire and rescue, and law enforcement organizations in trauma care.




Introduction


In 1992, the Naval Special Warfare Biomedical Research and Development program undertook a review of battlefield trauma care. The primary driver for this research effort was the realization that, although extremity hemorrhage was a leading cause of preventable death in combat casualties and tourniquets could be applied safely for short periods, tourniquet use was universally disparaged in both civilian and military prehospital trauma care. A thorough review of battlefield trauma care recommendations at the time resulted in the development of the first set of Tactical Combat Casualty Care (TCCC) Guidelines, a set of evidence-based, best-practice trauma care guidelines designed specifically for use on the battlefield, which were published in Military Medicine in 1996. The Wilderness Medical Society (WMS) assisted in reviewing the TCCC recommendations, reevaluating the interpretation of the available evidence that supported these recommendations, and discussing their implications for the battlefield and other austere environments.


After 2001, the lessons learned from the battlefields of Iraq and Afghanistan allowed continuous refinement of the TCCC Guidelines through the efforts of the Committee on Tactical Combat Casualty Care (CoTCCC). Importantly, combat medics, corpsmen, and pararescuemen (PJs) have consistently been a strong presence in the CoTCCC.


Now, in 2016, TCCC has been well-documented to have played a major role in achieving the highest casualty survival rate in the history of modern warfare in military units that train all of their members in TCCC.


TCCC is presently the standard for battlefield trauma care in the US Military and for many allied nations. CoTCCC members work closely with civilian trauma colleagues in the Hartford Consensus effort and the White House Stop the Bleed campaign to translate trauma care lessons learned on the battlefield to lives saved at home. In cooperation with the National Association of Emergency Medical Technicians (NAEMT), the CoTCCC has helped to develop TCCC-based trauma courses to assist in training civilian emergency medical services systems, fire and rescue, and law enforcement organizations in trauma care.




Tactical Combat Casualty Care and wilderness medicine


The wilderness environment presents some of the challenges experienced by medics on the battlefield: both patient and provider are typically in remote locations where evacuation is neither quick nor easy; there may be ongoing hazards to contend with; equipment is limited; the environment may be cold, hot, or aquatic; and the providers are often not trauma care specialists. The extreme diversity of nature that makes the wilderness so alluring complicates the care of patients with trauma in a myriad of ways, from whitewater rescue to high-angle rescue to avalanche rescue. Although many of these challenges are distinct from those encountered on the battlefield, there is a good deal of overlap in the approach to patients in these settings. A selected subset of the trauma care recommendations in TCCC and their applicability to the wilderness environment are reviewed and discussed later. The current TCCC Guidelines may be found on the Joint Trauma System (JTS) and NAEMT Web sites and in the Prehospital Trauma Life Support (PHTLS) textbook that is published every 3 to 4 years by NAEMT.




Approach to patients


TCCC recognizes that battlefield trauma care must combine good medicine with good small unit tactics and divides its recommendations into 3 phases: Care under Fire (while the unit is actively taking hostile fire), Tactical Field Care (the unit and the casualty are still in a prehospital combat environment but not actively engaging the enemy), and Tactical Evacuation Care (during which time the casualty is being transported to definitive care). In the wilderness, the terrain, environment, the location, and the nature of the activity in which the group is engaged provide variation and complexity to prehospital trauma care. An open fracture sustained during a multi-day caving expedition must be approached differently than one that occurs in an urban setting.


In both environments, the well-known ABC (airway, breathing, circulation) sequence of initial steps should be replaced with the acronym MARCH (massive bleeding, airway, respirations, circulation, and head/hypothermia.)


In patients with trauma, control of massive external hemorrhage is the most important initial step. Injury to a major vessel may result in death within as little as 5 to 10 minutes. When the hemorrhage is external, first responders have the ability to effectively intervene to stop the bleeding and should do so.




External hemorrhage control: tourniquets


The renewed focus on prehospital tourniquet use is one example of the lifesaving potential of the TCCC Guidelines. Until recently, military medics were taught that tourniquets should be used as a last resort, if at all, to control extremity hemorrhage. During the Vietnam conflict and at the start of the war in Afghanistan, tourniquet use was strongly discouraged. As a result, preventable death from extremity hemorrhage was common. Maughon’s study of 2600 combat fatalities in the Vietnam conflict found that 7.4% of the deaths examined resulted from extremity hemorrhage. Kelly and colleagues’ 2008 study of 982 combat fatalities sustained during the early years in Afghanistan and Iraq found that the incidence of death from extremity hemorrhage as a percentage of the total was essentially unchanged from the Maughon study at 7.8%. Holcomb and colleagues’ 2007 study of Special Operations fatalities noted that 3 of the 12 potentially preventable deaths were from extremity hemorrhage. These findings prompted the US Special Operations Command TCCC Transition Initiative in 2005, which expedited the fielding of tourniquets and hemostatic dressings to deploying Special Operations units. As a result, tourniquet and hemostatic dressing use increased in Afghanistan and Iraq and extremity hemorrhage deaths decreased. Eastridge and colleagues’ 2012 study of 4596 US combat fatalities from 2001 to 2011 noted that only 2.6% of total combat fatalities resulted from extremity hemorrhage; a 67% decrease. Kragh and colleagues’ landmark studies in 2008 and 2009 documented that extremity tourniquets saved lives and did not result in loss of limbs caused by tourniquet ischemia.


Tourniquets have proved to be lifesaving in the civilian and wilderness sectors as well. If a person attacked by an animal or a climber with an open fracture sustains a vascular injury with massive external hemorrhage, immediate application of an extremity tourniquet is required. The first responder then has time to convert the tourniquet to other methods of hemostasis when feasible.




External hemorrhage control: hemostatic dressings


When external hemorrhage occurs at sites that are not amenable to tourniquet use, another modality for achieving control of bleeding is the use of hemostatic dressings. The current TCCC Guidelines recommend Combat Gauze as the hemostatic dressing of choice and Celox Gauze and ChitoGauze as alternative choices. All of these hemostatic dressings should be applied with at least 3 minutes of firm, direct pressure.


Combat medics on the CoTCCC have consistently expressed a strong preference for gauze-type dressings rather than powdered or granular hemostatic agents, especially for wounds in which the bleeding vessel is at the bottom of a narrow wound tract. Gauze-based hemostatic dressings are more easily packed into the depths of such wounds where they can make direct contact with the bleeding vessel. Further, powdered or granular agents may present an ocular hazard if used in a windy environment or in the presence of rotor wash from helicopters. The Israeli Defense Force has reported excellent success in treating external hemorrhage in their combat wounded with Combat Gauze.


Zietlow and colleagues described the Mayo Clinic experience with Combat Gauze in civilian trauma, reporting a 95% success rate after the failure of standard dressings. Both TCCC-recommended tourniquets and hemostatic dressings should be included in all wilderness first aid kits.




The prehospital trauma airway


In trauma, managing the airway entails different considerations than those encountered in medical patients. Most airway fatalities in combat are related to direct maxillofacial trauma. Endotracheal intubation in the traumatized airway is challenging, even for experienced intubationists, and most military medics have little experience in intubating patients with airway trauma. Airway trauma on the battlefield is often best managed by allowing the casualty to maintain the sit-up-and-lean-forward position if the patient is conscious and able to do so. This position allows gravity and the patient’s protective reflexes to maintain a patent airway. The use of supraglottic airways in the prehospital setting is increasing, but these devices have not been well studied in trauma.


When the measures discussed above do not provide an adequate airway in a casualty with direct trauma to the maxillofacial region, a surgical airway is the intervention of choice. Combat medics have been shown to be able to perform this procedure with 100% success in a cadaver model when they are well trained and use a CricKey device, which is the recommended device in TCCC.


Should the need to secure the airway arise from unconsciousness secondary to traumatic brain injury (TBI) or hemorrhagic shock, nasopharyngeal airways (NPAs) have proved to be a good option. The NPA is an easily trained intervention and no airway fatalities were identified in the 2010 Mabry and colleagues review of this topic as being caused by NPA failure in nontraumatized airways.


In the wilderness setting, a lower incidence of direct maxillofacial trauma and a higher incidence of unconsciousness caused by TBI would be expected. Thus the use of an NPA is a good option in wilderness settings in which a skilled and equipped intubationist is not typically present. A surgical airway remains the emergent airway of last resort for patients with trauma in the wilderness.




Respirations/Breathing


Tension Pneumothorax


In the Vietnam conflict, tension pneumothorax was reported to be the second leading cause of preventable battlefield death. The incidence of death has decreased with the use of body armor that provides significant (but not complete) protection to the chest and back. In addition, combat medical personnel are now taught to use needle decompression (NDC) aggressively to treat suspected tension pneumothorax. The Eastridge and colleagues study noted that tension pneumothorax comprised only 0.2% of deaths among US combat fatalities, which represents a decrease of more than 90% in preventable deaths from this cause.


Current TCCC Guidelines call for casualties who have progressive respiratory distress following torso trauma to be suspected of having a tension pneumothorax and considered for NDC on the side of the injury with a 14-gauge, 8-cm (3.25-inch) needle/catheter unit. NDC is performed at the second intercostal space at the midclavicular line or the fourth or fifth intercostal space at the anterior axillary line. Needle entry into the chest should not be medial to the nipple line and the needle should not be directed toward the heart.


Use of an 8-cm (3.25-inch) needle rather than the previously used 5-cm (2-inch) needle was introduced after the Harcke and colleagues article in 2008. Those investigators noted that several of the cases in their autopsy series had failed attempts at NDC because the needle/catheter units used for the procedure were too short and did not reach the pleural space. This observation was followed by a virtual autopsy computed tomography (CT) study of chest wall thickness that found a mean chest wall thickness of 5.36 cm in the 100 military fatalities studied. Harcke and colleagues recommended that an 8-cm (3.25-inch) needle/catheter unit be used for NDC in order to achieve a 99% assurance of reaching the pleural space. Other investigators have presented similar findings and concerns. Harcke and colleagues’ findings led to the TCCC recommendation to use an 8-cm (3.25-inch), 14-gauge needle/catheter unit inserted to the hub. The authors are unaware of any reports of death from tension pneumothorax in US combat casualties caused by failed NDC since this change was made almost a decade ago. Bilateral NDC should be performed before resuscitation efforts are abandoned when a casualty with torso trauma or polytrauma has a prehospital cardiopulmonary arrest.


In the wilderness setting, death from tension pneumothorax is expected to be less common, although penetrating chest trauma may occur from hunting accidents and blunt chest trauma may result from falls, avalanche, or mountain bike accidents. Inclusion of an 8-cm (3.25-inch), 14-gauge needle in wilderness medical kits is a reasonable measure in order to be able to perform NDC in the unlikely event that this uncommon but life-threatening disorder is encountered in the wilderness. Improved success using an 8-cm (3.25-inch) needle (83%) compared with a 5-cm (2-inch) needle (41%) was reported by the Mayo Clinic. No complications were reported with either length needle.


Open Pneumothorax


An open pneumothorax (also sometimes referred to as a sucking chest wound) may result from a penetrating injury to the chest wall. When the defect in the chest wall is sufficiently large (usually two-thirds or more of the diameter of the trachea), air preferentially flows into the chest cavity via the defect in the chest wall, instead of into the lung via the trachea, as the casualty inhales. Air entering through the defect in the chest wall allows the lung on the affected side to collapse and impairs oxygen exchange.


Although there is little evidence that an open pneumothorax by itself (ie, without injury to underlying lung tissue and major vascular structures), is a potentially lethal injury, the impaired pulmonary gas exchange could potentially result in pulmonary compromise in a polytrauma casualty and contribute to secondary hypoxic brain injury in casualties with TBI.


Treatment of an open pneumothorax consists of applying a vented occlusive chest seal over the defect in the chest wall, thus preventing air from entering the pleural space through the defect in the chest wall. The vent in the chest seal prevents the development of a tension pneumothorax in the presence of an underlying lung injury and air leak. Commercially available vented and nonvented chest seals have been evaluated in animal studies. In the Kheirabadi study, chest seals were applied and then 200-mL increments of air were injected into the pleural cavity of thoracotomized swine every 5 minutes until either tension pneumothorax developed or the volume of air injected equaled 100% of the animal’s estimated total lung capacity. Tension pneumothorax did not develop in animals treated with vented chest seals (incorporating a 1-way valve that allowed air to leave but not to enter the pleural space). However, tension pneumothorax did occur in the animals with chest seals without valves. Vented chest seals, then, are preferred for the prehospital management of open pneumothorax, to be followed by tube thoracostomy when time, skills, and circumstances allow.


For wilderness medicine providers, open pneumothorax and the need for a vented chest seal is an injury pattern that might result from gunshot wounds sustained in hunting accidents. This injury, in the setting of delays to evacuation, is one that should be treated with prophylactic antibiotics, as described later.




Intravenous and intraosseous access


It has been a long-standing prehospital trauma care practice to establish intravenous (IV) access for individuals with significant trauma. TCCC has reconsidered this intervention. Starting IV lines inflicts significant cost in both time and logistics and may delay a combat unit’s ability to maneuver when needed. TCCC recommends that IV lines be started only for individuals who require fluid resuscitation as a result of hemorrhagic shock or who need IV medications, especially tranexamic acid (TXA) or analgesics. IV lines are easily dislodged, especially during combat operations. The TCCC curriculum describes a technique developed by medics in the 75th Ranger Regiment that helps to ensure that IV lines are not dislodged during casualty movement.




Intraosseous access


Establishing IV access is a fairly easy procedure unless the patient is obese, a small child, or in shock, or the person attempting to start the IV does not perform this procedure routinely. However, the last 2 caveats often apply to the battlefield setting. Another way to achieve vascular access is to use an intraosseous (IO) device.


This technique is easily trained and can be performed by prehospital providers with a high rate of success. Because the technique is performed based on bony landmarks rather than by visualizing peripheral veins, it is more easily performed under low light and night vision device conditions. The IO approach was proposed by TCCC as an alternative to IV lines on the battlefield in 2002 and quickly became widely used by combat medical personnel because the procedure is quickly and easily performed. IO access is now a widely used technique in the civilian sector as well. The Pyng FAST-1 and the EZ-IO devices have been the most widely used by the US Military in the recent conflicts. Although the risk of osteomyelitis is very low and the authors are unaware of any reports of this complication from the conflicts in Iraq and Afghanistan, both the potential for infection and the patient discomfort experienced with an IO procedure make using peripheral IV access the option of first choice when circumstances allow.


For practitioners of wilderness medicine, the indications for IV and IO access are basically the same as for the battlefield, except that it may be less common for medical providers in the wilderness setting to be prepared to perform fluid resuscitation from hemorrhagic shock.




Tranexamic acid


Noncompressible hemorrhage is the leading cause of preventable death in combat casualties. The large, prospective, randomized Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage (CRASH-2) study examined the effect of TXA administration in trauma patients at risk of bleeding and documented a small but statistically significant survival benefit. Although deep venous thrombosis is a known complication of trauma, there was no increase in the rate of vascular occlusive events in the TXA group. The subsequent subgroup analysis of the CRASH-2 data focused on deaths caused by bleeding rather than all-cause mortality and examined the effect of the timing of TXA administration on outcomes. The greatest benefit of TXA administration was obtained when the medication was given within 1 hour of the time of injury. TXA administered between 1 and 3 hours after the time of injury also reduced the risk of death caused by bleeding. However, TXA administered later than 3 hours after injury was observed to increase the risk of death from exsanguination.


The Military Application of Tranexamic Acid in Trauma Emergency Resuscitation Study (MATTERS) was performed at a role 3 facility in Afghanistan. The MATTERS investigators found a decreased mortality among combat casualties who received TXA, despite their being more seriously injured. In the subgroup of casualties who received massive transfusions (more than 10 units of red cells within the first 24 hours), mortality in the TXA group was markedly lower (14.4%) compared with the control group (28.1%). The CRASH-2 and MATTERS findings both supported the use of TXA in combat casualties who are either in hemorrhagic shock or at significant risk of that condition. As a result of these two studies, TXA was added to the TCCC Guidelines in 2011.


A subsequent report found a benefit from administering TXA in the prehospital setting. Studies examining the effect of giving TXA before elective surgical procedures associated with significant blood loss have consistently found that TXA reduces blood loss in these procedures and does not increase the risk of deep venous thrombosis. TXA is recommended in the TCCC Guidelines for casualties who are anticipated to need significant blood transfusion (eg, casualties with hemorrhagic shock, 1 or more major amputations, penetrating torso trauma, or evidence of severe bleeding.) The recommended dose is 1 g of TXA in 100 mL of normal saline or Lactated Ringers solution. TXA should be infused over 10 minutes to avoid the risk of hypotension and should be given as soon as possible after injury but not later than 3 hours after injury. In the event that evacuation to a medical treatment facility is delayed, a second infusion of 1 g of TXA should be administered after fluid resuscitation has been performed.


In the wilderness environment, TXA administration should be considered for trauma patients in shock, as well as those with penetrating torso trauma, severe external hemorrhage, or blunt trauma with suspicion of non-compressible hemorrhage. Falls and TBI are common in the wilderness and the value of TXA in reducing intracranial hemorrhage is currently an area of active investigation.

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Dec 2, 2017 | Posted by in Uncategorized | Comments Off on Tactical Combat Casualty Care and Wilderness Medicine
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