United States Department of Transportation

National Highway Traffic Safety Administration

Paramedic: National Standard Curriculum

(Reprinted with permission)

http://www.nhtsa.dot.gov/people/injury/ems/

Trauma: 4

Trauma Systems and Mechanism of Injury: 1

UNIT TERMINAL OBJECTIVE

4-1 At the completion of this unit, the Paramedic student will be able to integrate the principles of kinematics to enhance the patient assessment and predict the likelihood of injuries based on the patient’s mechanism of injury.

COGNITIVE OBJECTIVES

At the completion of this unit, the Paramedic student will be able to:

4-1.1 List and describe the components of a comprehensive trauma system. (C-1)

4-1.2 Describe the role of and differences between levels of trauma centers. (C-3)

4-1.3 Describe the criteria for transport to a trauma center. (C-1)

4-1.4 Describe the criteria and procedure for air medical transport. (C-1)

4-1.5 Define energy and force as they relate to trauma. (C-1)

4-1.6 Define laws of motion and energy and understand the role that increased speed has on injuries. (C-1)

4-1.7 Describe each type of impact and its effect on unrestrained victims (e.g., “down and under,” “up and over,” compression, deceleration). (C-1)

4-1.8 Describe the pathophysiology of the head, spine, thorax, and abdomen that result from the above forces. (C-1)

4-1.9 List specific injuries and their causes as related to interior and exterior vehicle damage. (C-1)

4-1.10 Describe the kinematics of penetrating injuries. (C-1)

4-1.11 List the motion and energy considerations of mechanisms other than motor vehicle crashes. (C-1)

4-1.12 Define the role of kinematics as an additional tool for patient assessment. (C-1)

AFFECTIVE OBJECTIVES

None identified for this unit.

PSYCHOMOTOR OBJECTIVES

None identified for this unit.

DECLARATIVE

I. Introduction

A. Epidemiology of trauma

1. A leading cause of death for people 1- 44 years of age

2. 140,000 unexpected deaths per year

3. Automobile related deaths are > 40,000

4. Penetrating trauma may exceed blunt in near future

5. Pre-incident, incident, post-incident phase

B. History

1. Complete and accurate history of incident will identify possibility for 95% of the injuries present

2. Incident site

a. Indications of severity of injury

3. Major factors of tissue injury

4. Amount of energy exchanged

5. Anatomical structures potentially involved

II. Trauma systems

A. Components

1. Injury prevention

2. Prehospital care

a. Treatment

b. Transportation

c. Trauma triage guidelines

3. Emergency department care

4. Interfacility transportation - if necessary

5. Definitive care

6. Trauma critical care

7. Rehabilitation

8. Data collection/ trauma registry

B. Trauma centers

1. Levels

2. Qualifications

a. Essential

b. Desired

3. Role

C. Transport considerations

1. Level of receiving facility

2. Mode of transport

a. Ground transport

(1) If appropriate facility can be reached within reasonable time

(2) To a more accessible landing zone for air medical transport

b. Air medical transport

(1) Indications

(2) Contraindications

(3) Procedure

III. Energy

A. Physical laws

1. Newton’s first law of motion

a. A body at rest or a body in motion will remain in that state until acted upon by an outside force

b. In a vehicle traveling at 50 mph, the occupant is also traveling at 50 mph

c. When the car stops, the occupant continues to travel at 50 mph until some force acts on the occupant

2. Conservation of energy

a. Energy cannot be created nor destroyed

b. It can be changed in form

c. Energy can be absorbed producing deformation of substance

3. Kinetic energy (KE)

a. KE = ½ the mass of the object multiplied by the velocity (speed) of the object squared (Mass/2 x V²)

b. Velocity (V) influences KE more than mass

c. Greater speed means more energy generated

4. Force

a. Force = Mass x Acceleration

b. Force = Mass x Deceleration

c. Mass x Acceleration = Force = Mass x Deceleration

d. Simply put, to accelerate a bullet from a the muzzle of a weapon requires the force from the explosion of the gunpowder; once the bullet is set in motion by this explosion, an equal amount of tissue destruction must occur inside the body to stop it as was used to start it

5. Energy law summary

a. Motion is created by force (energy exchange)

b. Force (energy exchange) must stop this motion

c. If such energy exchange occurs inside the body tissue damage is produced

B. Energy exchange

1. Cavitation

a. Energy exchange produces particle motion

b. Temporary cavity

(1) Short lived

(2) Produced by stretching

(3) Dependent on the elasticity of the object involved

(4) Produces particle compression at the limits of the cavity

c. Permanent cavity

(1) Visible when the energy exchange has been completed

(2) Produced by compression and destruction

2. Interaction between two bodies

a. At least one must be in motion

b. Both can be in motion

3. Dependent on number of particles involved in the interface of the interaction

a. Density of the interacting bodies

(1) Air density (few particles)

(a) Lung

(b) Intestinal tract

(2) Water density ( more particles)

(a) Vascular system

(b) Liver

(d) Muscle

(3) Solid density (thick particles)

(a) Bone

(b) Asphalt

b. Area on interaction

(1) Shape of object

(2) Position of object

(3) Fragmentation of object

C. Types on trauma based on ingress

1. Blunt

a. Tissue not penetrated

b. Cavitation away from site of impact

c. Cavitation in direction of impact

2. Penetrating

a. Tissue penetrated

b. Cavitation at 90^o to bullet pathway

(1) Tissue inline to penetration is crushed

IV. Blunt trauma

A. Vehicle collisions

1. Frontal

2. Lateral

3. Rear

4. Rotational

5. Roll over

B. Occupant collisions

1. Frontal impacts

a. Down and under

(1) Feet impact floor pan

(2) Knees impact dash

(a) Tibia impact

i) Knee dislocation

ii) Popliteal artery disruption

iii) Knee support disruption

(b) Femur impact

i) Femur fracture

ii) Acetabular posterior fracture dislocation

(3) Torso rotates

(a) Steering column

(b) Dash

b. Up and over

(1) Head impact

(a) Windshield

(b) Roof

(2) Chest impact

(a) Steering column

(b) Dash

(3) Abdominal impact

(a) Steering column

(b) Dash

2. Lateral impacts

a. Vehicle moves into and impacts body

(1) Chest

(2) Pelvis

(3) Body moves laterally

(a) Neck

i) Rotates

ii) Lateral flexion

iii) Combination

3. Rear impacts

a. Vehicle seat pushes body

(1) All body parts in contact with seat move

(2) Body parts not in contact dragged along with torso

b. Secondary impact if vehicle hits another object

(1) Similar to frontal impact

4. Rotational impacts

a. Part of vehicle stops; the rest remains in motion

b. Combination of frontal and lateral impacts

5. Roll over

a. Difficult to predict the body impacts

C. Organ collisions

1. Two types of injury from blunt trauma

a. Compression

b. Change in velocity

(1) Acceleration

(a) Shear

(b) Avulsion

(2) Deceleration

(a) Shear

(b) Avulsion

2. Organ collisions with different vehicular collisions

a. Frontal impacts

(1) Head

(a) Compression

i) Skull fractures

ii) Cerebral contusion

(b) Deceleration

i) Opposite end separation

ii) Hemorrhage

iii) Brain stem stretch

(2) Neck

(a) Compression

i) Vertebral body

a) Compression fracture

b) Hyperextension injury

- Posterior element compression

- Anterior body separation

c) Hyperflexion injury

- Anterior body compression

- Posterior element separation

(b) Shear

i) Not significant

(3) Thorax

(a) Chest wall

i) Compression

a) Fracture rib(s) - producing single rib fractures, flail chest, and/or pneumothorax

ii) Shear

a) Fracture thoracic spine

(b) Heart

i) Compression

a) Contusion

b) Rupture