Transcript SECTION 2 - Sam Scheller

Section 5: Trauma
Chapter 18
Mechanisms and
Patterns of Injury
Chapter 18: Mechanisms and Patterns of Injury
Objectives (1 of 2)
• Describe what is meant by “mechanism of
injury” (MOI).
• Discuss the importance of kinetic energy in
producing injuries.
• Describe the types of trauma and give
examples of injuries produced by each type.
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Chapter 18: Mechanisms and Patterns of Injury
Objectives (2 of 2)
• List some significant mechanisms of injury.
• Relate how the characteristics of the human
body tissues and organs and the laws of
physics apply to trauma injuries.
• Describe the process of using the
mechanism of injury to predict injuries.
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Chapter 18: Mechanisms and Patterns of Injury
Mechanism of Injury
• A concept that uses the characteristics of
the human body and the laws of physics
to understand, predict, and anticipate
injury and injury patterns
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Chapter 18: Mechanisms and Patterns of Injury
Tissue Characteristics
• Determine ease of injury
• Influence manner and frequency of injury
– Skin - lacerations
– Bones - fractures
• Skeleton provides protection for organs.
• Injuries are associated with motion.
• Extremities are more likely to be injured,
due to frequent motion.
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Chapter 18: Mechanisms and Patterns of Injury
Mechanism Terms (1 of 3)
• Force
–Any action that changes the rest or
motion of a body
• Body
–Any mass of matter distinct from
other masses
• Energy
–The capacity for doing work
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Chapter 18: Mechanisms and Patterns of Injury
Mechanism Terms (2 of 3)
• Work
– Force acting over distance
• Kinetic energy
– Energy of moving object
• Potential energy
– Product of weight, gravity,
and height
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Chapter 18: Mechanisms and Patterns of Injury
Mechanism Terms (3 of 3)
• Trauma
– End effect of force applied
to the human body
• Injury
– Actual type and extent of
damage to the body
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Chapter 18: Mechanisms and Patterns of Injury
Newton’s First Law
• Objects at rest tend to stay
at rest, and objects in
motion tend to stay in
motion, unless they are
acted upon by some force.
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Chapter 18: Mechanisms and Patterns of Injury
Law of Conservation of
Energy (1 of 2)
• Energy can neither be created nor destroyed,
but may be changed from one form to
another.
• When an object strikes the body, the energy
of motion is dispersed and dissipated by body
tissue; this can cause injury.
• Velocity or speed is a critical factor when
considering kinetic energy.
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Chapter 18: Mechanisms and Patterns of Injury
Law of Conservation of
Energy (2 of 2)
• Kinetic energy from falling is important to
consider.
• A body will accelerate to the terminal
velocity when falling (approx 200’/sec).
• Kinetic energy has both strength and
direction to cause the body to accelerate
or decelerate.
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Chapter 18: Mechanisms and Patterns of Injury
Types of Trauma (1 of 2)
• Penetrating
• Blunt (compression)
• Bending (hyperflexion,
hyperextension)
• Rotational
• Distraction (stretching)
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Chapter 18: Mechanisms and Patterns of Injury
Types of Trauma (2 of 2)
• Trauma can be a combination of types.
• Determined by magnitude and direction of
forces
• Techniques and equipment can modify,
control, and dissipate forces, ie, helmets
rolling with the fall.
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Chapter 18: Mechanisms and Patterns of Injury
Types of Injuries (1 of 4)
• Puncture wounds are caused by objects
that focus force and penetrate skin.
• Contusions and hematomas are caused by
blunt force:
– Do not break skin
– Injure skin and tissue underneath
– Can injure both organs and bones
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Chapter 18: Mechanisms and Patterns of Injury
Types of Injuries (2 of 4)
• Fractures, dislocations, and sprains occur
when joints are bent or rotated beyond
normal range.
• Crushing injuries can occur when blunt
forces act on the body, either:
– Gradual
– Momentary
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Chapter 18: Mechanisms and Patterns of Injury
Types of Injuries (3 of 4)
• Dislocations, lacerations, and fractures
occur when forces distract or stretch
tissue.
• Internal bleeding/organ contusions can
occur with rapid acceleration/deceleration.
– Tissue is subjected to blunt force from
contact with other body structures.
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Chapter 18: Mechanisms and Patterns of Injury
Types of Injuries (4 of 4)
• Amount of damage is proportional to
amount of energy involved.
• Injuries may reflect multiple types of
trauma (ie, bending and distraction).
• Be aware of fulcrum points that may
focus and multiply forces.
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Chapter 18: Mechanisms and Patterns of Injury
Patterns of Injury
• Concept that uses MOI to anticipate injuries
that are not readily apparent
• Injuries tend to occur in patterns with
predictable types:
– Vehicle collisions
– Falls
– Outdoor sports
– White water sports
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Chapter 18: Mechanisms and Patterns of Injury
MOI Factors (1 of 2)
• Energy: speed, direction, and focus
• Surface: smooth/rough, hard/soft
• Body: which parts, body position
• Trauma: blunt, penetrating, bending…
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Chapter 18: Mechanisms and Patterns of Injury
MOI Factors (2 of 2)
• External/internal injuries
• Signs and symptoms of specific injuries
not apparent: shock, fractures…
• Spinal injuries
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Chapter 18: Mechanisms and Patterns of Injury
Scene Size-Up (1 of 2)
• MOI is an essential part of
assessment.
• Use your experience to understand
and discover all injuries.
• Recognize that internal injuries can
be difficult to detect.
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Chapter 18: Mechanisms and Patterns of Injury
Scene Size-Up (2 of 2)
• Treat for internal injuries before they
become obvious.
• Determine the magnitude of forces,
areas of the body involved, and
external protection to identify the
significance of MOI.
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Chapter 18: Mechanisms and Patterns of Injury
Significant MOIs (1 of 3)
• Fall: 2.5 to 3 times body height, less if in motion
before fall
• Moderate to high speed vehicle collision:
– Fatality has occurred
– Patient was unrestrained
– Ejected from vehicle
– Vehicle rolled over
– Major intrusion into vehicle (motorcycle,
snowmobile)
– Patient was not wearing a helmet
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Chapter 18: Mechanisms and Patterns of Injury
Significant MOIs (2 of 3)
• Pedestrian struck by a vehicle moving
faster than 25 mph.
• Collision with another skier or rider
• Collision with a fixed object while skiing
or riding
• Gunshot wound to head, neck, chest
abdomen, or pelvis
• Patient unresponsive due to head injury
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Chapter 18: Mechanisms and Patterns of Injury
Significant MOIs (3 of 3)
• Shock or respiratory distress with
no explanation
• Avalanche burial
• Explosion
• Struck by a falling object
• High voltage or high amperage
electrical shock
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