ch02 blunt

Paramedic Care:

Principles & Practice

Volume 5

Trauma Emergencies

Chapter 2

Blunt Trauma

Introduction to Blunt Trauma Blunt trauma is the most common cause of trauma-

related death and disability.

True nature of the injury is often hidden.

Physics 101

Kinetics Kinetics is a branch of physics dealing with objects in

motion and the energy exchanges that occur as objects

collide.

Deals with motion and energy exchanges

Kinetics of Impact Two basic principles of kinetics:

Laws of inertia

Energy conservation

Law of Inertia Newton’s first law:

“A body in motion will remain in motion unless acted upon

by an outside force.”

“A body at rest will remain at rest unless acted upon by an

outside force.”

Energy Conservation Law of Energy Conservation

“Energy can neither be created nor destroyed. It can only

be changed from one form to another.”

All the energy of motion converts to other energy forms.

Types of Energy Potential

Kinetic

Kinetic Energy Kinetic energy of an object while in motion is

measured by the following formula:

KE = mass (weight) x velocity (speed)2

2

Kinetic Energy When you double an object’s weight, you double its

kinetic energy.

As speed (velocity) increases, there is a larger

(squared) increase in kinetic energy.

Releasing energy slowly, as occurs with braking,

results in a tolerable transfer of energy while stopping.

Force Newton’s second law of motion explains the forces at

work during a collision:

Force = Mass (Weight) X Acceleration (or Deceleration)

Force The formula emphasizes the importance of the rate at

which an object changes speed.

Gradual changes in speed are usually uneventful.

When significant kinetic energy is applied to human

anatomy, we call it trauma.

Biomechanics of Trauma

Biomechanics of Trauma Describes the actual injury process.

Bound by the laws of physics:

Inertia, energy conservation, and force

Trauma is divided into two general categories:

Blunt

Penetrating

Blunt Trauma The Force enters the

body, not the object.

What Causes the Injury? Compression (opposite of stretching)

Stretching (opposite of compression)

Shearing

Skin Resistant to compression and stretching (hides injuries)

Bone Very strong but will fx with shearing forces

Lung Compression is bad

Hollow Organs Tolerant unless filled with fluid or air

Biomechanics of Trauma

Blunt

Closed injury

Indirect injury to

underlying structures

Transmission of energy

into the body

Biomechanics of Trauma

Penetrating

Open injury

Direct injury to

underlying structures

Automobile Collisions 44,000 people die each year on U.S. highways.

Events of Impact:

Vehicle collision

Body collision

Organ collision

Secondary collisions

Additional injuries

Vehicle receives a second impact

Automobile Collisions

Automobile Collisions

Restraints

Seatbelts

Airbags (SRS)

Reduce blunt chest

trauma

Cause: hand, forearm,

and facial injury

Check for steering

wheel deformity

Side airbags

Child Safety Seats

Automobile Collisions Types of Impact

Frontal

Lateral

Rotational

Rear-end

Rollover

Frontal Impact Up-and-Over

Tenses legs = bilateral femur fracture

Hollow organ rupture and liver laceration

Similar chest trauma

Axial loading

Down-and-Under

Knee, femur, and hip fracture

Chest trauma – steering wheel

Paper bag syndrome

Ejection

Lateral Impact

15% of MVCs but 22% of

deaths

Upper extremity injury

Rib, clavicle, humerus,

pelvis, femur fracture

Lateral compression

Ruptured diaphragm

Spleen fracture

Aortic injury

Rotational Impact

Vehicle struck at oblique

angle

Less serious injuries

unless strike a

secondary object

© Mark C. Ide

Rear-End Collisions

Rear-end

Seat propels the occupant

forward

Head is forced backward

Stretching of neck muscles and

ligaments

Hyperextension and

hyperflexion

© Mark C. Ide

Rollover

Rollover

Multiple points of impact

Ejection or partial ejection

Less injury with restraints

© Mark C. Ide

What kind of car do you see?

Vehicle Collision Analysis Hazards

Crumple zones

Intrusion

Deformity of vehicle

Use of restraints Undeployed airbags should be deactivated by trained

fire/extrication personnel

Intoxication Fatal collisions: >50% involve legal intoxication

Recreational accidents

Automobile Collision

Evaluation

© Ray Kemp/911 Imaging

Automobile Collisions Vehicular Mortality

Head: 48%

Internal (torso): 37%

Spinal and chest fracture: 8%

Extremity fracture: 2%

All other: 5%

Automobile Collision

Evaluation

Collision Questions

How did collision occur?

Direction?

Speed?

Similar/different sized?

Secondary collisions?

Cause of Collision

Weather and visibility?

Alcohol involved?

Skid marks?

Auto Interior

Starring of windshield?

Steering wheel deformity?

Dash deformity?

Intrusion?

Motorcycle Collisions Serious injuries can occur with high- and low-speed

collision

Types of Impact

Frontal

Angular

Sliding

Ejection

Initial bike/object collision

Rider/object

Rider/ground

Pedestrian Collisions

Adults

Adults turn away

Bumper strikes lower

legs first

Victim rolls up and over

and thrown

Pedestrian Collisions

Children

Children turn toward

Femurs, pelvis often

injured

Thrown away or run

over

Recreational Vehicle

Collisions Lack structure and restraint system

Types of Vehicles

Snowmobiles

Personal watercraft

ATVs

Often see injuries in children due to lack of skills and training

Blast Injuries

Explosion

Pressure Wave

Blast Wind

Victim Displacement

© Joshua Menzies

Blast Injuries

Explosion Pressure Wave

Structural collapse

Blast wind

Burns

Projectiles

Terrorist devices may contain nails, screws, or other

materials meant to cause additional injury and

destruction.

Personnel Displacement

Explosion Blast Injury Phases

Primary: Heat of the explosion

Secondary: Trauma caused by projectiles

Tertiary: Personnel displacement and structural collapse

Explosion Blast Injury Assessment

Be alert for secondary device

Initial scene size-up important

Establish Incident Command System (ICS)

Evaluate for secondary hazards

Injury Patterns:

Rupture of air- or fluid-filled organs

Lung: Late manifestation (heat and pressure)

Hearing loss

Explosion Lungs

Forceful compression and distortion of chest cavity

Compression and decompression

Pulmonary embolism, dyspnea, hemoptysis, pneumothorax

Abdomen

Compression and decompression

Release of bowel contents

Diaphragm rupture from pushing of organs up into thorax area

Explosion Ears

Initial hearing loss

Injury improves over time

Penetrating Wounds

Care as any serious open wound or impaled object

Burns

Treatment consistent with traditional management

Other Types of Blunt Trauma Falls

The initial impact may involve other body surfaces with the forces of deceleration

Evaluating a fall

Determine the point of impact

The fall height

The impact surface

The transmission pathway of forces along the skeleton

Other Types of Blunt Trauma Sports Injuries

Sports injuries are most commonly produced by extreme

exertion, fatigue, or by direct trauma forces.

Injuries can be secondary to acceleration, deceleration,

compression, rotation, hyperextension, or hyperflexion.

Other Types of Blunt Trauma Crush Injury

Cause

Structural collapse, explosion, MVC, industrial, or agricultural

Great force to soft tissue and bones

Tissue stretching and compression

Extended pressure results in anaerobic metabolism distal to

compression

Return of blood flow, toxins to entire body

Severe hemorrhage due to severe damaged blood vessels

Questions?