Operations Study Guide for the EMT Test

Major Incident Types

A call to a major emergency incident can present in many ways that require a variety of management strategies. Here are some of the possibilities:

Mass-Casualty Incidents

Traditionally, a mass-casualty incident (MCI) has been defined as an emergency with three or more patients or one that stresses the EMS system’s typical capabilities. An MCI can also include a situation with the imminent potential to become an MCI. When an MCI occurs, crews should initiate triage and the command system.

Hazardous Materials

Hazardous material incidents can be very unsafe. The EMT needs to recognize the incident and request additional resources from resource lists. Transport vessels are marked by DOT placards marking system. Control zones need to be established for incident management.

Here are some concepts to know:

• hazardous material—any substance that can harm people, property, or the environment, such as chemicals, gases, and explosives

• hazardous material (HazMat) incident—an emergency situation during which hazardous materials are released or threatened to be released; an incident that poses a risk to people, property, or the environment, including chemical spills, gas leaks, etc. and requires a special response

• container—the packaging or vessel that holds and stores material; may be transported

• bulk storage container—a large package or vessel used to store excess quantities of certain materials

• secondary containment—a safety system built around a hazardous material container to catch any leaks or spills if the primary container fails; a backup barrier

• intermodal tanks—a type of bulk container designed to safely transport large quantities of powders, liquids, or gases; reusable and often made of metal

• non-bulk storage vessels—a container used to hold hazardous materials; store smaller quantities than bulk containers; can be a drum, bag, or cylinder

• drums—cylindrical containers used to store and transport materials

• placards—diamond-shaped signs, typically found on trucks, tanks, or containers, used to identify the type of hazardous material found inside

• safety data sheet (SDS)—A standardized information sheet used to convey important information about a chemical or hazardous material that may be encountered. This information includes what the material is, the risks, and how to protect yourself from it.

• bill of lading—a shipping document that lists what materials are being transported, where they are going, and who is responsible for them; can be thought of like a receipt or contract between the shipper and the carrier

• Chemical Transportation Emergency Center (CHEMTREC)—a 24/7 emergency call center that provides first responders with key information about hazardous materials quickly during an incident

• hot zone—the area in an emergency scene or incident designated as the most dangerous; contains the immediate threat or hazard; most likely location for exposure

• warm zone—the area of an emergency scene that is just outside of the hot zone; also known as the contamination reduction zone; often where decontamination and limited medical care are conducted

• cold zone—the area of an emergency scene that is safe and free from hazards where there is no chance of threat or contamination

• decontamination area—a designated area on a hazardous material scene where all individuals and equipment involved in the incident are cleaned to remove any hazardous substances; typically located in the warm zone, and from here all are moved to the cold zone

• toxicity—the ability of a substance to cause harm or injury to the body through ingestion, inhalation, or absorption

Vehicle Extrication and Special Rescue

EMTs are not usually responsible for special rescue without extra training. Extrication typically occurs around the EMT and patient and requires constant communication to be done safely.

Safety

The need to focus on safety during rescues and extrication cannot be overstressed. It requires a mindset focused on safety and proper protective gear depending on the hazards present. It could include helmets, high-visibility clothing, turnout gear, and protective gloves.

Vehicle Safety Systems

Modern vehicles have a variety of safety systems that can pose hazards to rescuers after a crash. This includes shock-absorbing bumpers that can suddenly release, hitting rescuers. Undeployed airbags can spontaneously deploy and require extra caution.

Here are some concepts to know:

• shock-absorbing bumpers—Commonly found on modern vehicles, these types of bumpers are designed to absorb and reduce the force of a collision. They help to protect occupants and minimize damage. They may also hide underlying vehicle damage. When approaching vehicles equipped with these bumpers, responders should avoid walking directly in front of the vehicle. Additionally, be aware that they may be resistant to some cutting tools or other rescue operations.

• airbags—These are safety devices found in vehicles that rapidly inflate in response to collisions to cushion and protect occupants. First responders should exercise caution when entering these vehicles as airbags are deployed with an explosive charge. Those that are not fully or adequately deployed during a collision may discharge during rescue, potentially causing further injury to the patient or rescuers.

• side-impact airbags—These safety devices are installed in a vehicle’s doors, seats, or roofline and rapidly deploy and inflate during a collision. They are meant to protect the head, chest, and pelvis from injury. First responders should be cautious when entering vehicles for undeployed airbags, since they can still deploy.

Extrication Fundamentals

Vehicle extrication is complex and dangerous. The EMT’s primary role is to operate safely and stabilize and package the patient. There are ten phases, including hazard control, access, removal, and transfer. Good communication and clear roles among all team members are critical.

Here are some concepts to know:

• extrication—the safe removal of a patient who is trapped, often requiring specialized tools and coordinated rescue efforts

• entrapment—when a patient is trapped or pinned by wreckage or another object and cannot free themselves without assistance

• access—the process of gaining entry to a patient who is trapped; can be either simple or complex, often requiring the use of specialized tools and rescue techniques

• hazard control—the process of identifying, reducing, or eliminating dangers at an emergency scene, such as fire, traffic, power lines, fuel leaks, etc.

• simple access—gaining entry to a trapped patient without the use of tools or force, such as by opening an unlocked door or window

• complex access—gaining entry to a patient when simple methods are futile; requires the use of tools, special equipment, or special rescue techniques

Terrorism

Terrorism is an ongoing threat that can happen anywhere. Terrorists have increased their targeting of civilians, and EMTs need to be prepared for such incidents.

Terrorism Facts

Terrorism refers to a violent act, typically against civilian targets, intended to instill fear. Terrorists can single out individuals or organized groups and have domestic or international agendas. Recent terrorism events in the US have included the Boston Marathon bombing and a number of mass shootings.

Here are some concepts to know:

• international terrorism—the unlawful use of violence or the threat of violence by individuals or groups across national borders

• domestic terrorism—the unlawful use of violence or the threat of violence by individuals or groups within a country

Weapons of Mass Destruction

Weapons of mass destruction (WMDs) are intended to bring about a large number of casualties. WMDs can be biological, nuclear, incendiary, chemical, or explosive weapons. While terrorists have used all of the previous types except nuclear, they have favored explosives.

Here are some concepts to know:

• weapon of mass destruction (WMD)—devices or agents (chemical, biological, radiological, nuclear) capable of causing large-scale injury, death, or damage to people, property, or the environment

• weapon of mass casualty (WMC)—tools, devices, or agents that can cause a large number of injuries or fatalities in a single event

• B-NICE—A mnemonic used to classify types of weapons of mass destruction or mass casualty.

  • B- biological—pathogens like viruses, bacteria, or toxins that cause disease

  • N- nuclear—devices that release nuclear energy, radiation, or blasts

  • I- incendiary—weapons that cause fires or heat-based destruction

  • C- chemical—toxic chemicals that cause harm through inhalation, ingestion, or contact

  • E- explosive—devices that cause destruction and trauma through blasts or shrapnel

• weaponization—the process of converting a substance, device, or piece of technology into a form that can be used as a weapon to cause harm

• state-sponsored terrorism—the use of violence or threats of violence by a governing body or with its support to intimidate, coerce, or harm others

• dirty bomb—an explosive device that combines conventional explosives with radioactive material, designed to spread contamination, cause panic or harm, or kill

The EMT Response

The type and nature of the weapon will affect the appropriate EMT response to a WMD incident. Be familiar with the various approaches that might be needed in different situations.

Here are some concepts to know:

• covert—something done in secret or hidden from plain view to avoid detection

• secondary device—an explosive or harmful device intentionally placed at a scene to target first responders or bystanders after an initial incident has occurred

• cross-contamination—the transfer of harmful substances from one person, object, or surface to another, potentially spreading disease or injury

Chemical Agents

Chemical agents are gases and liquids that can be dispersed in the air to kill and injure. They include vesicants, choking agents, nerve agents, and cyanides. Treatment is usually based on symptoms, though a few, such as cyanide and nerve agents, have antidotes.

Here are some concepts to know:

• persistency—the amount of time a hazardous substance, chemical, or agent remains active and dangerous in the environment after its release

• volatility—the tendency of a substance, especially a chemical, to vaporize quickly at normal temperatures, increasing the risk of inhalation or explosion

• route of exposure—the way in which a hazardous substance enters the body, such as inhalation, ingestion, absorption, or injection

• vapor hazard—a dangerous situation created by airborne chemical vapors that can be inhaled

• contact hazard—a dangerous situation in which a substance can cause harm through direct contact with the skin, eyes, or other body surfaces

• vesicants—chemical agents that cause blistering of the skin, eyes, and respiratory tract on contact

• sulfur mustard (H)—a type of vesicant chemical warfare agent causing blistering of the skin and mucus membranes, eye irritation, and respiratory damage

• mutagen—a substance that can cause genetic mutations in DNA

• lewisite (L)—a vesicant chemical warfare agent that contains arsenic and is highly toxic

• phosgene oxime (CX)—a vesicant/urticant chemical warfare agent whose effects appear instantly

• chlorine (Cl)—a toxic chemical gas that can cause respiratory irritation, coughing, and difficulty in breathing upon contact or inhalation

• phosgene—a toxic chemical gas that primarily affects the respiratory system

• nerve agents—highly toxic chemicals that disrupt normal nervous system function; can cause uncontrolled muscle spasms, respiratory failure, and convulsions

• LD50—lethal dose 50%: the amount of a substance that is required to kill 50% of a test population

• off-gassing—the release of toxic or hazardous vapors over a period of time, which can pose a risk to responders even after its initial release

• nerve-agent aging—the process by which a nerve agent chemically changes over time, making it more stable and resistant to antidotes

• DuoDote auto-injectors—pre-filled auto-injectors which combine atropine and pralidoxime (2-PAM) used to treat nerve agent poisoning

• Cyanides—highly toxic chemicals that interfere with the body’s ability to use oxygen at the cellular level

• SLUDGEM—a mnemonic used to remember the signs and symptoms of nerve agent or organophosphate poisoning

  • S- salivation—excessive drooling
  • L- lacrimation—tearing of the eyes
  • U- urination—involuntary
  • D- defecation—diarrhea
  • G- gastrointestinal upset—cramps, vomiting
  • E- emesis—vomiting
  • M- miosis—constricted pupils

• miosis—constricted pupils; typically a symptom of nerve agent poisoning, opioid overdose, or other toxic exposures

Biologic Agents

Biologic agents have been used by terrorists in various ways; most recently it was anthrax powder in the US mail. Biologic agents include bacteria, viruses, and neurotoxins. They can be disseminated via multiple routes, and the incubation period and initial similarity to routine illnesses make them hard to detect.

Here are some concepts to know:

• dissemination—the process of spreading a hazardous agent into the environment to expose people, animals, or areas.

• disease vector—any living organism that can transmit infectious agents from one host to another, causing disease

• contagious—a disease or condition that can be easily transmitted from one person to another

• incubation—the period of time between exposure to an infectious agent and the appearance of the first sign or symptom of disease

• virus—a tiny, infectious agent that can only reproduce inside the living cells of a host

• bacteria—single-celled microorganisms that can cause disease

• smallpox—a contagious and sometimes deadly disease process with signs and symptoms that often include fever, fatigue, and a distinctive rash with raised bumps that can turn into scabs

• viral hemorrhagic fevers (VHF)—a group of serious illnesses caused by viruses that damage blood vessels, such as Ebola and Marburg; highly contagious and can lead to serious bleeding and organ failure

• anthrax—a serious disease caused by bacteria, sometimes utilized as a biological weapon; inhalation, ingestion, or skin contact can lead to severe infection

• bubonic plague—a severe disease caused by a bacterium that is usually spread through flea bites; can cause fever, weakness, and swollen, painful lymph nodes

• lymphatic system—part of the body’s immune system that helps fight infection and remove waste; made up of lymph nodes, vessels, and lymphatic fluid

• buboes—swollen, painful lymph nodes that appear in the groin, armpit, or neck; a symptom commonly seen in the bubonic plague

• pneumonic plague—a severe lung infection caused by bacteria spread through respiratory droplets; causes fever, cough, chest pain, and difficulty in breathing

• neurotoxins—poisons that damage or disrupt the nervous system and can cause muscle weakness, paralysis, seizures, or respiratory distress; often derived from biological sources

• botulinum—a powerful neurotoxin produced by bacteria affecting the body by blocking nerve signals to the muscles, causing paralysis and possibly leading to death; one of the most lethal toxins; can be used as a biological weapon

• ricin—a highly toxic protein that comes from castor beans; can cause severe organ damage, respiratory failure, and death if inhaled, injected, or ingested; considered a biological agent

• syndromic surveillance—the monitoring of health data, symptoms, or patterns in a population to detect outbreaks or emerging diseases or bioterroristic events

• points of distribution (PODS)—locations set up by public health agencies to distribute medications, vaccines, or supplies quickly to large groups of people during emergencies

Radiological/Nuclear Devices

Radiation is energy emitted by radioactive decay. The energy is emitted in the form of alpha, beta, gamma, and neutron radiation. Each type has a different penetration potential. Shielding, exposure time, and distance from the source are important protective factors.

Here are some concepts to know:

• radioactive material—any substance that emits radiation, such as alpha, beta, or gamma particles

• ionizing radiation—high-energy radiation that can remove electrons from atoms or molecules

• decay—the process by which radioactive substances break down, releasing energy in the form of radiation

• alpha—heavy, positively charged particles emitted by some radioactive materials; has a low penetration and can be stopped by skin or paper

• beta—high-speed negatively charged electrons emitted from some radioactive materials that can penetrate the skin and cause burns

• gamma (x-ray)—high-energy electromagnetic radiation emitted by radioactive materials; requires shielding as it can penetrate past the skin deep into the body and cause serious internal damage

• neutron radiation—free neutrons that are released during radioactive decay; very dangerous to human tissue as it can penetrate deeply, similar to gamma; requires protection

• radiological dispersal device (RDD)—considered to be a “dirty bomb”; a device that combines conventional explosives with radioactive materials

• Special Atomic Demolition Munitions (SADM)—a small, portable, nuclear device that can be detonated leading to infrastructure destruction and radioactive hazard

• exposure time—the amount of time a person is in direct contact with a hazardous substance or environment; decreasing exposure time reduces risk

• distance—the space between a person and a hazard source; increasing the distance reduces the risk

• shielding—the use of barriers or protective devices to block or reduce exposure to hazards, such as wearing lead during an X-ray

Incendiary and Explosive Devices

Incendiary devices cause fires and use explosive energy to cause damage and injury. They have been the most common type of terrorist device, and can come in various sizes, from small backpack bombs to truck bombs. Secondary devices are always a concern to the EMT.

Here are some concepts to know:

• improvised explosive device (IED)—This is a homemade or unconventional bomb designed for the purpose of causing injury, damage, or death.

• primary, secondary, tertiary, and quaternary blast injuries—Blast injuries are classified into four categories based on the mechanism of trauma experienced during an explosion.

  • Primary blast injuries are caused by the blast wave itself.

  • Secondary blast injuries are caused by flying debris or shrapnel leading to penetrating injury.

  • Tertiary blast injuries are caused by victims being thrown by the blast, resulting in blunt trauma.

  • Quaternary blast injuries encompass all other explosion related injuries, such as burns, inhalation injury, crush injury, etc.

• pulmonary blast injury—These are lung injuries caused by the pressure waves of an explosion.