EMS CHAPTER 11

The first part of the patient assessment process; steps taken when approaching an emergency call, including checking scene safety, taking standard precautions, noting the mechanism of injury (MOI) or nature of illness (NOI), determining the number of patients, and requesting additional resources.

Scene Size-Up

Action required if two patients are found at a vehicle collision

Request a second ambulance.

The only predictable aspect of emergency situations

They are often unpredictable and can pose many dangers if personnel are not careful.

Protocol upon arriving at a scene that has already been deemed safe

Perform your own scene size-up.

Point at which scene size-up officially begins

Before the ambulance comes to a complete stop; observe the scene while approaching and re-evaluate before exiting the vehicle.

Clues indicating escaped hazardous materials

Placards, damaged transport vehicles, escaping liquids, fumes, or vapor clouds.

Danger zone

The area around the wreckage of a vehicle collision or other incident within which special safety precautions must be taken.

Danger zone dimension when there are no apparent hazards

At least 50 feet in all directions.

Danger zone dimension when fuel has been spilled

A minimum of 100 feet in all directions.

Danger zone dimension when a vehicle is on fire

At least 100 feet in all directions.

Danger zone dimension when electrical wires are down

At least one full span of wires away from the poles to which broken wires are attached.

Guideline for establishing a danger zone involving hazardous materials

Consult the Emergency Response Guidebook (ERG).

Danger zone dimension when explosives are involved

At least 2,000 feet in all directions.

Appropriate protective apparel on the scene of an accident

An ANSI-approved reflective vest.

Significance of unusual odors detected during scene size-up

May indicate the presence of hazardous materials.

Vehicle parking position when hazardous materials are detected at a scene

Uphill and upwind.

Action taken when fighting, threatening words, or violence are observed on arrival

Do not proceed or enter the scene; there is a significant risk that the scene is dangerous to the crew.

Protocol whenever a weapon is observed on scene

Exercise extreme caution and maintain distance until law enforcement secures the area.

Implication of an emergency call that is “too quiet”

It should immediately raise your suspicion of danger.

Precaution required when responding to a location with a known history of violence

Use extra caution.

BSI

Body Substance Isolation.

Routes through which patient body substances can enter an EMT’s body

Cuts, abrasions, mucous membranes, or other openings in the skin.

Mechanism of injury (MOI)

A force or forces that may have caused injury.

Primary indicator used to predict injury patterns in motor vehicle crashes

The mechanism of injury (MOI).

Powder found on a patient and inside a car after a collision that resembles smoke

Nontoxic powder released during airbag deployment.

Four main types of physical force causing trauma

Direct, twisting, forced flexion or hyperextension, and indirect force.

The three collisions involved in a motor vehicle crash

1. Vehicle collision (vehicle strikes an object)
2. Body collision (occupant strikes the vehicle interior)
3. Organ collision (internal organs strike interior surfaces of the body)

Injuries suggested by a collapsed or bent steering column

Chest wall injury with potential rib fractures, lung injury, or heart damage.

Law of inertia

A body in motion will remain in motion, and a body at rest will remain at rest, unless acted upon by an outside force.

Collision type that is a common cause of neck and head injuries

Rear-end collisions.

Two injury patterns associated with head-on collisions

1. Up-and-over pattern
2. Down-and-under pattern

Up-and-over collision pattern

The occupant travels up and over the steering wheel, frequently striking the windshield (especially when unrestrained); causes head, neck, and chest injuries along with airway/breathing compromise.

Down-and-under collision pattern

The occupant's body travels downward, striking the dashboard or steering wheel with the knees; commonly causes knee, leg, and hip injuries.

Assessment step required following airbag deployment

Carefully lift and move the deflated airbag to inspect the steering wheel or dashboard for concealed structural damage.

Mechanism of common injuries in rear-end collisions

The head is thrown violently backward and forward, commonly causing neck and head trauma (such as whiplash), particularly when the headrest is improperly positioned.

Injuries associated with side-impact (T-bone) collisions

Lateral displacement of the body, causing trauma to the head, neck, chest, abdomen, pelvis, and skeletal system, often resulting in severe internal organ damage.

Reason rollover collisions are particularly hazardous

They involve multiple unpredictable impacts and present a high risk of ejection, leading to complex and severe multi-system trauma.

Rotational impact collision dynamics

A vehicle is struck and spins; the initial impact causes trauma, and secondary collisions with other vehicles or obstacles cause additional injury patterns.

Reason internal organs can be damaged without visible external trauma

Internal organs continue moving after the body frame stops, causing them to collide against skeletal structures or tear from deceleration forces.

Four key factors to evaluate regarding fall injuries

1. Height of the fall
2. Surface fallen onto
3. Body part that struck the surface
4. Objects that interrupted the fall

Height threshold defining a severe fall for an adult

Greater than 20 feet.

Height threshold defining a severe fall for a pediatric patient

Greater than 10 feet, or more than 2 to 3 times the child's height.

Penetrating trauma

An injury caused by an object passing through the skin or other body tissues.

Blunt force trauma

An injury caused by a blow that strikes the body without penetrating the skin or underlying tissues.

Low-velocity penetrating trauma

Injuries caused by hand-propelled weapons or objects, such as knives or broken glass.

Medium-velocity penetrating trauma

Injuries typically caused by handguns and shotguns.

High-velocity penetrating trauma

Injuries typically caused by rifles and high-powered assault weapons.

Index of suspicion

An awareness that unseen injuries may be present based on the mechanism of injury.

Nature of illness (NOI)

What is medically wrong with a patient; the medical condition causing the emergency.

Cavitation

Pressure-related damage where kinetic energy from a bullet creates a high-pressure wave, producing a temporary cavity substantially larger than the projectile itself.

Three primary sources for determining nature of illness (NOI)

1. The patient
2. Family members or bystanders
3. The physical scene

The five steps of scene size-up

1. BSI / Standard precautions & Scene safety
2. Determine Mechanism of Injury (MOI) / Nature of Illness (NOI)
3. Determine the number of patients
4. Request additional resources
5. Consider cervical spine (C-spine) immobilization