transport decision. tactical evacuation care tactical evacuation care refers to care provided when a casualty is being evacuated and en-route to higher levels of medical care. care providers at this phase are at even less risk of imminent harm as result of hostile actions. due to improved access to resources and the tactical situation, more advanced interventions can be provided to casualties such as endotracheal intubation. patient re-assessments and the addressing of issues that were not or were inadequately addressed previously are also major components of this phase. in tactical evacuation (tacevac), casualties are moved from a hostile environment to a safer and more secure location to receive advanced medical care. tactical evacuation techniques use a combination of air, ground and water units to conduct the mission depending on the location of the incident and medical centres. ground vehicle evacuations are more prevalent in urban locations that are in close proximity to medical facilities. requests for evacuation of casualties and pertinent information are typically communicated through 9-line medevac and mist reports. tactical evaluation is an umbrella term that encompasses both medical evacuation (medevac) and casualty evacuation (casevac). medical evacuation platforms are typically not engaged in combat except in self-defence and defence of patients. medevac takes place using special dedicated medical assets marked with a red cross. casualty evacuation is through non-medical platforms and may include a quick-reaction force aided by air support. for aircraft involved tacevac situations there are many considerations that need to be accounted for. firstly, the flying rules vary widely depending on the aircraft and units in play. the list of determinants to create the tacevac strategy include the distances and altitudes involved, time of day, passenger capacity, hostile threat, availability of medical equipment/personnel, and icing conditions. as mentioned tacevac is more advanced than tccc, it also includes training to/for: improve breathing provide supplemental oxygen administer tranexamic acid (txa) deal with traumatic brain injuries fluid resuscitation blood product administration blood transfusion preventing and treating hypothermia canadian armed forces there are three levels of tactical combat casualty care providers in the canadian armed forces. combat first aid every soldier receives a two-day combat first aid training course. the course focuses on treating hemorrhages, using tourniquets and applying dressings, and basic training for casualty management. tactical combat casualty care a select number of soldiers are chosen to participate in an intense 2-week tactical combat casualty care course where soldiers are provided with additional training. overall, they are trained to work as medic extenders since they work under the direction of medics. tactical medicine the tactical medicine (tacmed) course is offered exclusively to medics. the tactical medicine program provides training for advanced tactical combat casualty care and is the highest level of care provided by the canadian armed forces in a battlefield setting. medics are trained to treat and manage patients using the marche protocol. the marche protocol prioritizes potential preventable causes of death in warfare as follows: massive hemorrhage control airway management respiratory management circulation bleeding control intravenous (iv)/ intraosseous (io) access fluid resuscitation tourniquet reassessment hypothermia prevention head injuries eye injuries everything else monitor patient pain management head-to-toe assessment address all wounds found antibiotics tactical evacuation preparation documentation of care and findings care under fire care under fire happens at the point of injury. according to tactical combat casualty care guidelines, the most effective way to reduce further morbidity and mortality is to return fire at enemy combatants by all personnel. the priority is to continue the combat mission, gain fire superiority, and then treat casualties. the only medical treatment rendered in care under fire is the application of direct pressure on massive bleeding. tactical combat casualty care recommends a tourniquet as the single most important treatment at the point of injury. it is recommended during care under fire to quickly place tourniquets over clothing, high, and tight; the tourniquet should be reassessed when out of danger in the tactical field care phase. tactical field care tactical field care is considered to be the backbone of tactical combat casualty care and consists of care rendered by first responders or prehospital medical personnel while still in the tactical environment. the acronyms march and paws help personnel remember crucial treatment steps while under duress. march the march acronym is used by personnel to remember the proper order of treatment for casualties. massive hemorrhage. the most potentially survivable cause of death is hemorrhage from extremity bleeds, however more than 90% of 4596 combat mortalities post september 11, 2001 died of hemorrhage associated injuries. it is recommended to apply a committee on tactical combat casualty care (cotccc) approved tourniquet for any life-threatening extremity hemorrhages. tourniquets during tactical field care should be placed under clothing 2 to 3 inches above the wound, with application time written on the tourniquet. airway. non-patent or closed airway is another survivable cause of death. airway injuries typically occur due to inhalation burns or maxillofacial trauma. if a person is conscious and speaking they have a patent open airway, while nasopharyngeal airway could benefit those who are unconscious and breathing. however, unconscious casualties who are not breathing could require surgical cricothyroidotomy, as endotracheal intubation is highly difficult in tactical settings. respirations. tension pneumothorax (ptx) develops when air trapped in the chest cavity displaces functional lung tissue and puts pressure on the heart causing cardiac arrest. thus, open chest wounds must be sealed using a vented chest seal. tension pneumothorax should be decompressed using a needle chest decompression (ncd) with a 14 gauge, 3.25 inch needle with a catheter. ventilation and/or oxygenation should be supported as required. circulation. it is more important to stem the flow of bleeding than to infuse fluids, and only casualties in shock or those who need intravenous (iv) medications should have iv access. signs of shock include unconsciousness or altered mental status, and/or abnormal radial pulse. iv should be applied using an 18 gauge catheter and saline lock in tactical field care, secured by transparent would-dressing film. tranexamic acid (txa) should be given as soon as possible to casualties in or at risk of hemorrhagic shock. an intraosseous (io) device could also be used for administering fluids if iv access is not feasible. head injury/hypothermia. secondary brain injury is worsened by hypotension (systolic blood pressure under 90 mmhg), hypoxia (peripheral capillary oxygen saturation under 90%), and hypothermia (whole body temperature below 95 fahrenheit or 35 celsius). medical personnel can use the military acute concussion evaluation (mace), while non-medical personnel can use the alert, verbal, pain, unresponsive (avpu) scale to identify traumatic brain injury. the "lethal triad" is a combination of hypothermia, acidosis, and coagulopathy in trauma patients. since hypothermia can occur regardless of ambient temperature due to blood loss, the hypothermia prevention and management kit (hpmk) is recommended for all casualties. paws the paws acronym is used by personnel to remember additional casualty care items that should be addressed. pain. proper management of pain reduces stress on a casualty's mind and body, and have reduced incidents of post-traumatic stress disorder (ptsd). pain management is shown to reduce harmful patient movement, improves compliance and cooperation, and allows for easier transport as well as improved health outcomes. antibiotics. all battlefield wounds are considered contaminated, and thus any penetrating injury should receive antibiotics at the point of injury as well as in tactical field care. the recommended parenteral antibiotics are 1g ertapenem or 2g cefotetan, which can treat multi drug-resistant bacteria. if the casualty can tolerate oral fluids, 400mg moxifloxacin can be administered orally instead of ertapenem or cefotetan. wounds. assessing the casualty for additional wounds improves morbidity and mortality. first responders must address burns, open fractures, facial trauma, amputation dressings, and security of tourniquets. prior to movement, reassessment of wounds and interventions is very important. casualties with penetrating trauma to the chest or abdomen should receive priority evacuation due to the possibility of internal hemorrhage. splinting. explosions (such as from improvised explosive device or land mines) that cause lower extremity traumatic amputation cause forces to move upward through the body, which may cause further bone disruption, hollow organ collapse, or internal bleeding. thus, first responders should use the combat ready clamp (croc), the junctional emergency treatment tool (jett), or the sam junctional tourniquet to control junctional hemorrhage and stabilize the pelvis. in cases of penetrative eye trauma, responders should first perform a rapid field test of visual acuity, then tape a rigid shield over the eye to prevent further damage, and also give 400mg oral moxifloxacin as soon as possible. pressure must never by applied to an eye suspected of penetrative injury. evaluating effectiveness in order to evaluate the effectiveness of tactical combat casualty care, a study was conducted which analyzed us military casualties who died from an injury that occurred while they were deployed to afghanistan or iraq from october 2001 to june 2011. of the 4,596 casualties, 87% died in the pre-medical treatment facility, prior to receiving surgical care. of the casualties in the pre-medical treatment facility, 75.7% of the prehospital deaths were non-survivable, while 24.3% of deaths were potentially survivable. instantaneous non-survivable mortalities included physical dismemberment, catastrophic brain injury, and destructive cardiovascular injury. non-instantaneous non-survivable mortalities included severe traumatic brain injury, thoracic vascular injury, high spinal cord injury, and destructive abdominal pelvic injury. these injuries are very difficult to treat given currently fielded medical therapies such as tactical combat casualty care. in terms of potentially survivable mortalities, 8.0% of mortalities were associated with airway obstruction. majority of mortalities (90.9%) which were classified as potentially survivable mortalities were attributed to hemorrhage, with 67.3% of the hemorrhage being truncal, 19.2% junctional, and 13.5% extremity. during the study period, there were no effective protocols put in place to control junctional or truncal sources of hemorrhage in the battlefield, which suggests a gap in medical treatment capability. this study shows the majority of battlefield casualties which occur prior to receiving surgical care are non-survivable. however, of the casualties which are survivable, the majority of deaths can be attributed to hemorrhages. developing protocol which can control and temporize hemorrhage in the battlefield would improve the effectiveness of tactical combat casualty care, and decreases the number of casualties in the battlefield. another study analyzed the effectiveness of tourniquets for hemorrhage control, which are used in tactical combat casualty care. a four-year retrospective analysis showed that out of 91 soldiers who were treated with tourniquets, 78% of tourniquets were applied effectively. the success rate for tourniquets applied to upper limbs was 94% while the success rate for tourniquets applied to lower limbs was 71%. the difference between the success rates can be attributed to the tourniquets themselves, as in another study, tourniquets applied on healthy volunteers resulted in a much lower success rate for lower limbs in comparison to upper limbs. therefore, the tourniquets themselves can be redesigned to increase its effectiveness and improve tactical combat casualty care. a prospective study of all trauma patients treated at the canadian-led role 3 multinational medical unit (role 3 mmu) established at kandahar airfield base between february 7, 2006, to may 20, 2006, was conducted to examine how tactical combat casualty care interventions are delivered. the study concluded that tourniquets are effective, but must be used appropriately. the distinction between venous and arterial tourniquets must be reinforced in tactical combat casualty care training. tactical combat casualty care courses must also train soldiers to remove tourniquets for the purposes of reassessing trauma after the patient and caregiver is no longer under enemy fire. this is because the risks of iatrogenic ischemic injury of prolonged use of tourniquets outweigh the risks of increased blood loss. the study also identified technical errors in performing needle decompressions. all needle decompressions were performed at least 2 cm medial to the mid-clavicular line and well within the cardiac box. this may result in injury to the heart and surrounding vasculature. tactical combat casualty care training must reinforce using landmarks when performing needle decompressions. this is especially useful since soldiers may have to perform this procedure in poor lighting conditions.