Introduction

Terrorism, unfortunately, continues to be perpetrated against innocent civilians throughout the world. This activity ranges from stabbings, shootings, bombings, or car-rammings by the lone terrorist, to large-scale destructive acts such as that of the Twin Towers on September 11, 2001. One must also prepare for chemical, biological, radiological, or nuclear terrorism (CBRN). A combination of extreme fundamentalist ideologies and social networking has accentuated terrorism in many parts of the world. To achieve their nefarious goals of inflicting as many casualties on civilians as possible, the terrorists choose to target places with high civilian concentration. Hence, they disproportionately attack urban areas such as buses, trains, shopping malls, and restaurants. Emergency Medical Services (EMS) must prepare themselves to deal with some of the unique challenges of terrorist attacks.

Issues of Concern

The safety of the EMS responder to the scene of a terrorist attack is the top priority. One needs to be aware of a secondary detonation of an explosive device, and it is often necessary to wait until the police bomb disposal experts verify that the scene is safe. In a shooting incident, if the perpetrator has not yet been neutralized, one must not approach the scene unless properly trained in tactical medicine with appropriate protective gear. A responder to a chemical, biological, or radiological attack needs to have the indicated personal protective equipment (PPE).  One must also be wary of building collapse as well as inhalation injuries after a fire.[1]

Blast Injuries

Terrorists pack their bombs with nails, bolts, and other metal objects to inflict maximum harm. They are made to be transported easily and then either hidden at the scene or strapped to the body of a suicide bomber. The four types of blast injuries from urban bomb explosions result in large numbers of patients with devastating injuries.[2][3][4][5]

To inflict maximum death and harm, terrorists place the bombs to explode in closed spaces. Mortality is the highest in ultra-confined spaces such as buses or trains.[5] In general, there is a higher injury severity score, and surgical interventions are more intense for those presenting to the hospital following terrorist attacks than those presenting due to other trauma. 

Primary blast injury occurs secondary to the effects of the blast wave. Forces such as spalling, acceleration, implosion mechanisms as well as pressure differences cause devastating effects on structures in the body containing air such as the tympanic membranes, lungs, and bowels. Tympanic membrane perforation occurs in more than 50% of patients exposed to a blast of greater than 15-50 psi. These perforations can be a marker of coexisting injuries such as a blast lung, which requires higher pressures of 50-100 psi and may present subtly. Air emboli in the coronary or pulmonary vessels may be a primary cause of death.[4][5]  

Secondary blast injury, a form of penetrating trauma, results from shrapnel such as flying pieces of metal, glass, and other objects. One should beware that even benign, superficial appearing skin wounds may indicate significant injury due to the penetration of metal bolts, nails, and pellets. Biologic foreign body implantation may also occur due to flying bone fragments from the suicide bomber, other victims, or the patient himself.[6][7][8][9]

The lungs may be affected by primary blast lung injury or lacerations from secondary mechanisms. Both may present as a pneumothorax. Hemothorax is less common in a classic blast injury.[4][5]

Tertiary blast injury results from the blast throwing the victim. This type of injury is accentuated in closed and ultra-confined spaces as the victim's body may be propelled against stationary objects causing blunt trauma, amputation, or death.

Quaternary blast injuries include burns caused either by the explosion itself or by other flammable substances in the area. These may consist of all types of classic burn injuries, including chemical and contact burns. Others included in this category: asphyxia, inhalational trauma, radiation exposure, and psychological effects of the event.[10]

Often the blast causes a combination of injuries, including blunt and penetrating trauma as well as burns. This combination of injuries is known as the multidimensional injury pattern and is unique to bomb explosions.[11]

Penetrating Trauma

Stabbings from terrorists differ from non-terrorist stabbings. They are more frequently on the upper part of the body, carried out with large knives, and involve multiple stab wounds.[12] Shootings range from those with handguns to semiautomatic rifles. Because semiautomatic rifles can accept magazines with large numbers of bullets, as well as high-velocity rounds, more people were killed and wounded in incidents that involved semiautomatic weapons compared to other types of firearms.[13]

Targeted Automobile Ramming Mass Casualty (TARMAC) Attacks

A recent choice of terror has been car and truck ramming known as Targeted Automobile Ramming Mass Casualty (TARMAC) attacks. The size/weight of the vehicle, as well as the body part hit, will determine the extent of the injury pattern. Blunt injury to the head, torso, abdomen, and extremities are common.[14]

Chemical Terrorism

Accessibility to chemical or toxicological substances renders them potential weapons in the hands of terrorists. Possible agents include organophosphates used as insecticides or irritants such as chlorine and ammonia. However, it can also involve agents that don't have industrial use, including asphyxiants such as carbon monoxide or vesicants such as mustard gas.[15]

Biologic Terrorism

Biologic terrorism encompasses events such as infecting others with salmonella or anthrax by individual attackers or the large-scale spread of biologic agents by a terrorist organization. The maximum effect could be perpetrated by airborne spread, although contamination of the food and water supply can also occur.  The most lethal agents include those in Tier 1 (Formerly Group A and the most significant risk to public health): anthrax, tularemia, hemorrhagic fever viruses, and botulism.[16]

Nuclear Terrorism

Nuclear terrorism includes the detonation of a nuclear bomb by terrorists, an explosion of a dirty bomb, or the takeover of a nuclear facility. It may also involve dispersing nuclear material into a water supply. It is worth noting that percussion forces, projectiles, and thermal injuries killed the majority of victims in Hiroshima and Nagasaki as opposed to radiation. The biologic effects of radiation exposure occur between 2 and 10 Gy (less than this amount, the victim probably will not require medical intervention, and more than this, the person is very unlikely to survive). The most immediate problems are bone marrow suppression and damage to the gastrointestinal tract. Long-term effects include thyroid cancer, solid tumors, and leukemia.[17]

Clinical Significance

Command, control, and communication require emphasis. EMS, as well as hospital administrators, should be included as it is essential to anticipate surge capacity. The inclusion of all local hospitals is vital in contingency plans as the number of severely injured patients may become overwhelming even for a level 1 trauma center.[18]  

As pertains to the command structure, consider the inclusion of a Law Enforcement Medical Coordinator (LEMC) who is a tactical medical officer and understands both tactical and EMS issues. They would be involved in any operational input and would serve as a liaison with EMS and the fire department. They can advise on limitations to the operational aspect of the medical plans, integrate between the protection and rescue elements of the response team. They need to continuously monitor and updated threats to the law enforcement staff in the hot zone and EMS and fire department staff in the warm zone.

The area around the attack, (especially if caused by CBRN), needs to be cordoned off into an inner danger zone, a hot zone (non-permissive zone), warm zone (semi-permissive zone), and an outer cold zone (permissive zone) where the casualty clearing station is placed. These warm or cold zones are typically where triage occurs.

Security is essential at the scene of the event. There have been numerous cases of secondary bombings where an additional intentional device or bomber detonated after prehospital providers entered the scene, resulting in rescuers then becoming victims. This fact means that health responders require verification from police or security services that the site is safe before they enter a scene and begin resuscitation and rescue efforts. Any tactical medical officers should have personal protective equipment that includes Kevlar or body armor. If the sprinklers go off in the building, then the providers need to be prepared to work in a wet environment and need to be wary of electric shocks. The casualty collection point needs to be outside of any area which may be threatened by the terrorist or potential bomb. Emergency Medical Services (EMS) receive instruction in S-C-ABC- safety first, catastrophic hemorrhage, and then the ABCs (airway, breathing, and circulation).

In instances with multiple terrorists, there may be numerous areas that are cordoned off and unsafe. Some countries and jurisdictions have created a Hazardous Area Response team whereby prehospital personnel with tactical training and appropriate equipment, enter the danger zone. However, this is usually by law enforcement personnel, such as SWAT paramedics, who should only perform basic life-saving procedures such as massive hemorrhage control, opening the airway, and rapid evacuation. They need to be mobile and therefore don't carry enough equipment for sustained care for large numbers of casualties.[19]

In contrast to this, the permissive environment (cold zone) is a safe area and includes the ability to administer RSI or advanced analgesia and the performance of other procedures.[20] The warm zone (semi-permissive environment) is in a spectrum between the non-permissive and permissive areas. In this area, the immediate threat is no longer active. If this is due to CBRN, then proper personal protective equipment (PPE) is required. Besides stopping major bleeding with tourniquets, and continuing basic airway management, one should also treat pneumothorax at this point with needle application.

Other protocols exist for first responders to terrorist MCIs. One is the "3 Echo Protocol- Enter, Evaluate, and Evacuate" which emphasizes early identification of casualties, usually by law enforcement and early treatment of life-threatening hemorrhage, and safe evacuation.[21] Another approach uses the THREAT acronym- Threat suppression, Hemorrhage control, Rapid extrication, Assessment, and Transport.[22]

Triage

Various field triage strategies exist. These include START (Simple Triage and Rapid Treatment: the ability to obey commands, assess the respiratory rate, and radial pulse or capillary refill), SALT (Sort, Assess, Life-Saving Interventions, Treatment, and/or Transport), Triage Sieve and Sort (using respiratory rate and either capillary refill or heart rate), or CareFlight Triage (ability to obey commands, the presence of respiration, and being able to palpate a radial pulse). Implementation of one of these protocols is essential.[23],[24]

After extensive experience with suicide bombing, Magen David Adom (MDA - Israel's Emergency Medical Services) during the years 2002-2005, successfully adopted the concept of "save and run." The only actions performed at the scene are for hemorrhage control (application of bandages and tourniquets) and the advanced life support actions of airway control/intubation and needle application for tension pneumothorax. The most severely injured patients are usually taken to the closest level one trauma center. However, other considerations, such as the large numbers of casualties or severity of life-threatening injury, may result in patient transport to the nearest medical centers for emergency treatment and stabilization. Some patients will then undergo secondary transfer to a level one trauma center.[25]

Catastrophic Hemorrhage

Direct pressure with bandages is the initial protocol. Tourniquets should be applied to the extremities when required due to life-threatening arterial bleeding. It is to remember to tighten the windlass component properly. One can also use hemostatic agents, with or without junctional tourniquets, to areas such as the axilla and groin. Elevating and splinting of affected limbs is crucial. If the pelvis is unstable, then using a sheet as a binder may be necessary.[26]

Chemical Terrorism

The EMS responder must don appropriate protective gear. The PPE ranges from Level A, which consists of a chemically resistant suit and full-face self-contained breathing apparatus to Level D, which consists of overalls and no respiratory protection. The higher the level of equipment, the more challenging it will be for the EMS provider to operate.  Notably, some experts advocate the decontamination of all toxicological mass casualty victims at the hospital. The EMS provider, while in protective gear, can undress the victim in the ambulance, and then proper decontamination can be done at the hospital. Basic resuscitation protocols and antidotes can be provided on the ambulance.[15]

Biological Terrorism

Depending on the type of agent, precautions need to be taken by EMS personnel. These range from contact and airborne precautions to the need for N95 protective respirators. The patient may have to be isolated from other patients, both prehospital as well as in the hospital. The EMS provider may require pre-exposure and post-exposure prophylaxis for diseases such as smallpox and anthrax.[16]

Radiological and Nuclear Terrorism

Management of a radiological disaster must be with personal protection that includes masks, eye protection, gowns, gloves, and boots. There will also be a hot zone, a warm zone (buffer zone), and a cold zone. The victims should be evaluated with a Geiger counter to identify their contamination level with radioactive material. If contaminated, they should undergo decontamination. Clothes should be removed and double bagged. Then face rinsing with skin washing with soap and water is next. Internal decontamination may later be necessary.[27]

Stress

Terrorist attacks can be at least as emotionally intense as any other major mass casualty event; EMS providers frequently suffer from at least short-term post-traumatic stress. Counseling for critical incident stress is a recommended strategy. Empathetic care must begin from the time the patient arrives in the emergency department and continue throughout the process of their medical care.[28] To prevent depression and PTSD, disaster preparedness training, critical incident stress debriefing, and shift work in prolonged responses are helpful.

Conclusion

• Always ensure scene safety before first responders can be allowed on site.
• Coordination of personnel and medical resources is critical.
• Awareness of the multidimensionality of blast injury, especially if combined with a CBRN material. This trauma may include a clinical scenario of head injury, burns, blast lung, and intra-abdominal or thoracic injury as well as contamination from chemical, biological, or nuclear material.