Trauma Systems Mechanism of Injury

1
Trauma Systems / Mechanism of Injury
Chapter 18
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Trauma

• Epidemiology
• Trends in trauma deaths

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Phases of Trauma Care

• Three phases
• Pre-incident
• Incident
• Post-incident

4
Prevention of Trauma Deaths

• Deaths from trauma can be categorized as
  occurring in 3 periods
• Immediate
• Early
• Late

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Comprehensive Trauma System Components

• Injury prevention
• Prehospital care (including treatment,
  transportation, and trauma triage guidelines)
• Emergency department care
• Interfacility transportation (if needed)
• Definitive care
• Trauma critical care
• Rehabilitation
• Data collection/trauma registry

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Trauma System

• Role of the paramedic
• Trauma centers
• Hospital categorization

7
Transport Considerations

• Appropriate level of care and hospital
  destination is based on
• Patient needs and condition
• Advice of medical direction
• Ground transport
• Aeromedical transport

8
Energy

• Trauma injuries
• Caused by a transfer of energy from an external
  source to the human body
• Extent of injury is determined by
• Type of energy applied
• How quickly it is applied
• To what part of the body it is applied

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Physics Laws

• Newton's first law of motion
• Conservation of energy law
• Newton's second law of motion

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Kinematics

• The process of predicting injury patterns
• Consider the following when evaluating the trauma
  patient
• Age
• Protective factors
• Mechanism of injury
• Force of energy applied
• Anatomy
• Energy

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Blunt Trauma

• An injury produced by the wounding forces of
  compression and change of speed, which may
  disrupt tissue
• Direct compression or pressure on a structure
• Most common type of force applied in blunt trauma
• Amount of injury depends on
• Length of time of compression
• Force of compression
• Area compressed

12
Motor Vehicle Collision

• Three separate impacts as the energy is
  transferred
• Vehicle strikes an object
• Occupant collides with the inside of the car
• Internal organs collide inside the body

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Motor Vehicle Collision

• Injuries that result from automobile crashes
  depend on
• Type of collision
• Position of the occupant inside the vehicle
• Use or nonuse of active or passive restraint
  systems

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Motor Vehicle Collision

• May be classified by type of impact
• Head on
• Lateral
• Rear end
• Rotational
• Rollover
• Forces of compression and change of speed produce
  predictable injury patterns in each type of
  collision

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Head-on (Frontal) Impact

• Results when forward motion stops abruptly
• First collision
• Second collision
• Third collision

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Head-on (Frontal) Impact

• Occupant usually travels in one of two pathways
  in relationship to dashboard
• Down and under
• Up and over

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Down-and-under Pathway

• Occupant travels downward into vehicle seat and
  forward into dashboard or steering column
• Knees strike dashboard
• Upper legs absorb most of the impact

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Up-and-over Pathway

• As the body in forward motion strikes the
  steering wheel, the momentum of the thorax is
  absorbed by the ribs and underlying structures

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Lateral Impact

• Occurs when a vehicle is struck from the side
• Injury patterns depend on whether the damaged
  automobile remains in place or moves away from
  the point of impact

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Rear-end Impact

• A vehicle struck from behind rapidly accelerates
• Causes auto to move forward under the occupant
• In forward collisions, the sum of both vehicles'
  speeds is the velocity that produces damage
• In rear-end collisions, the difference between
  the two speeds is the damaging velocity

21
Rotational Impact

• Occurs when an off-center portion of the
  automobile strikes an immoveable object
• Or one that is moving more slowly or in the
  opposite direction

22
Rollover Accidents

• Occupant tumbles inside auto and is injured
  wherever body strikes vehicle
• Impacts occur at many different angles
• Potential for multiple-system injuries
• Predictable injuries difficult to categorize
• May produce any of the injury patterns associated
  with other types of collisions

23
Restraints

• Lap belts
• Diagonal shoulder straps
• Airbags
• Child safety seats

24
Deceleration Injuries

• When body organs are put into motion after an
  impact, they continue to move against the
  structures that attach them to the body
• Risk of separation of body organs from their
  attachments
• Injury to the vascular pedicle or mesenteric
  attachment may lead to brisk or exsanguinating
  hemorrhage

25
Head Injuries

• When the head strikes a stationary object, the
  cranium comes to an abrupt stop
• Brain tissue continues to move until it is
  compressed against the skull

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Thoracic Injuries

• Aorta frequently injured by severe, lethal
  deceleration forces
• Usually sheared at the level of its ligamentum
  arteriosum attachment
• Frank rupture leads to rapid exsanguination

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Abdominal Injuries

• Intraabdominal organs and retroperitoneal
  structures (most commonly the kidneys) may be
  affected by deceleration forces

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Head Injuries

• Compression injuries to the head may result in
• Open fractures
• Closed fractures
• Bone fragment penetration (depressed skull
  fracture)
• Associated injuries include
• Brain contusion
• Lacerations of brain tissue

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Head Injuries

• Compression forces to the skull can also produce
  hemorrhage from
• Fractured bone
• Meningeal vessels
• The brain itself
• If facial structures are involved, soft tissue
  trauma and facial bone fractures may occur
• Always consider CNS injury and cervical fracture

30
Head Injuries

• Compression injury to the vertebral bodies can
  result in
• Compression fracture
• Hyperextension injury
• Hyperflexion injury

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Thoracic Injuries

• Lungs and heart are frequently involved in
  compression injury to the thorax
• Serious lung injury can occur from compression
  forces due to a paper-bag effect

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Paper-Bag Effect
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Abdominal Injuries

• Compression injuries can cause
• Solid organ rupture
• Vascular organ hemorrhage
• Hollow organ perforation into the peritoneal
  cavity
• Common injuries
• Lacerations to spleen, liver, and kidney
• Rupture of a full bladder
• Predictable injuries

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Other Motorized Vehicular Collisions

• Injuries from other motorized vehicular
  collisions include those involving
• Motorcycles
• All-terrain vehicles (ATVs)
• Snowmobiles
• Motor boats
• Water bikes
• Jet skis
• Farm machinery

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Personal Protective Equipment

• Protective equipment for riders of small motor
  vehicles includes
• Boots
• Leather clothing
• Eye protection
• Helmets
• Structured to absorb energy of an impact,
  reducing injuries to face, skull, and brain
• Nonuse of helmets increases head injuries by more
  than 300

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Pedestrian Injuries

• Three primary mechanisms of injury (multiple
  impacts) in auto-pedestrian collisions
• First impact occurs when the bumper of the
  vehicle strikes the body
• Second occurs as the pedestrian strikes the hood
  of the vehicle
• Third occurs when the pedestrian strikes the
  ground or another object

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Pedestrian Injuries

• Predictable injuries depend on
• Whether the pedestrian is an adult or a child
• Variations in the height of the pedestrian in
  relation to the bumper and hood of the car
• Velocity of the vehicle

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Adult Pedestrian

• Most adult pedestrians turn away from oncoming
  auto
• Injuries are often a result of lateral or
  posterior impacts
• Initial impact
• Second impact
• Third impact

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Child Pedestrian

• Children tend to face oncoming vehicle
• Injuries are often the result of a frontal impact
• Initial impact
• Second impact
• Third impact

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Common Sports Associated with Injuries

• Contact sports
• Football
• Basketball
• Hockey
• Wrestling
• High-velocity activity sports
• Downhill skiing
• Water skiing
• Bicycling
• Rollerblading
• Skateboarding
• Racquet sports
• Swimming and diving

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Causes of Sports-Related Injuries

• Forces of acceleration and deceleration
• Compression
• Twisting
• Hyperextension
• Hyperflexion

42
Blast Injuries

• Term used to describe damage to a patient exposed
  to a pressure field produced by an explosion of
  volatile substances
• Other causes
• Primary blast injuries
• Secondary blast injuries
• Tertiary blast injuries
• Miscellaneous blast injuries

43
Vertical Falls

• In predicting injuries associated with falls,
  evaluate the
• Distance fallen
• Body position of the patient on impact
• Type of landing surface struck
• Injuries associated with vertical falls are a
  result of deceleration and compression

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Penetrating Trauma

• All penetrating objects, despite velocity, cause
  some form of tissue disruption (penetrating
  trauma)
• Damage occurs because of two types of forces
• Crushing
• Stretching

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Penetrating Trauma

• Factors that determine which of the two
  mechanisms of injury predominates
• Character of the penetrating object
• Its speed of penetration
• Type of body tissue it passes through or into

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Cavitation

• A temporary or permanent opening produced by a
  force that pushes body tissues laterally away
  from the tract of a projectile

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Cavitation

• Amount of cavitation produced by the transfer of
  energy is directly related to the
• Density (number of particles) of tissue in a
  given body area
• Ability of the body tissue to return to its
  original shape and position

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Permanent and Temporary Cavitation
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Ballistics

• The effect of a projectile on the body is
  determined primarily by the energy created and
  dissipated by the object into surrounding tissues
• Damage and energy levels of projectiles
• Injuries caused by penetrating trauma may be
  classified as those resulting from three energy
  levels low, medium, and high

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Low-energy Projectiles

• Knives, needles, and ice picks
• Cause tissue damage by their sharp, cutting edges
• Amount of tissue crushed is usually minimal
  because the amount of force applied in the
  wounding process is small
• Tissue damage is usually limited to the pathway
  of the projectile

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Stab wound knife pierced liver, pancreas,
splenic vein
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Stab Wounds

• When evaluating a patient with a stab wound
• Attempt to identify the type of wounding object
• Consider the possibility of
• Multiple wounds
• Embedded penetrating objects
• Extensive internal damage to organs of the thorax
  and abdomen
• Penetration of multiple body cavities
• A high degree of suspicion is also indicated for
  stab wounds to areas of the back and flank

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Medium-energy Injuries

• Usually caused by firearms that have a muzzle
  velocity of less than 1500 feet per second
• All handguns and some rifles are considered
  medium-energy weapons
• Injury tract produced by is usually is 2 to 3
  times the diameter of the projectile

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High-energy Injuries

• Usually caused by firearms with a muzzle velocity
  of more than 1500 feet per second
• Injury tract produced by high-energy weapons is
  usually 2 to 3 times the diameter of the
  projectile

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Wounding Forces of Medium and High-energy
Projectiles

• Tissue disruption is caused by the localized
  crush of tissue in the missile's path and the
  momentary stretch of the surrounding tissues
• Differences in wounds caused by projectiles vary
  with the amount and location of crushed and
  stretched tissue

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Wounding Forces

• The wounding forces of a missile depend on
• The projectile mass
• Deformation
• Fragmentation
• Type of tissue struck
• Striking velocity
• Range

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Wounding Forces
Bullet passing through tissue. Outward stretching
of the permanent cavity as the tissue particles
move away from the penetrating missile cause the
temporary cavity.
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Shotgun Wounds

• Shotguns are short-range, low-velocity weapons
• Energy transferred to body tissue and the
  resultant tissue damage depend on
• Gauge of the gun
• Size of the pellets
• Powder charge
• Distance from the victim

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Entrance and Exit Wounds

• Appearance of entrance and exit wounds is
  affected by
• Range
• Barrel length
• Caliber
• Powder
• Weapon

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Entrance Wound

• Usually round or oval
• May be surrounded by an abrasion rim or collar
• If the firearm was discharged at intermediate or
  close range, powder burns (tattooing) also may be
  present

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Bullet Wound
Powder marks show this 0.22-caliber bullet wound
was inflicted at close range.
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Shotgun Wound
Short-range shotgun wound to forearm.
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Exit Wounds

• If present, are generally larger than entrance
  wounds
• As the bullet exits the body, the skin may
  explode
• Resulting in ragged and torn tissue
• Splitting and tearing often produces a star-burst
  or stellate wound

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Exit Wound
Exit wound caused by powerful shotgun at close
range.
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Head Injuries

• Gunshot wounds to the head are typically
  devastating
• Patients frequently sustain severe face and neck
  injuries
• Significant blood loss
• Difficulty in maintaining airway control
• Spinal instability

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Thoracic Injuries

• Gunshot wounds to the thorax may result in severe
  injury to the pulmonary and vascular systems
• Pneumothorax and tension pneumothorax should be
  considered
• Vascular trauma may result in massive internal
  and external hemorrhage
• Thoracic trauma may be present without visible
  chest wounds

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Abdominal Injuries

• A gunshot wound to the abdomen usually requires
  surgery to determine the extent of injury
• May affect multiple organ systems
• Damage to air-filled and solid organs
• Vascular injury
• Spinal column and spinal cord injury

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Extremity Injuries

• Gunshot wounds to the extremities
• Are occasionally life-threatening
• May result in lifelong disability