Download Kinematics of Trauma

Quantum Physics and the TimeSpace Continuum
An in depth and highly detailed analysis
of the physical universe and it’s
relevance to the pre-hospital emergency
medical practicum.
TRAUMA KINEMATICS
An Introduction to the Physics of
Trauma
Trauma Statistics
• Over 150,000 trauma deaths/year
– Over 40, 000 are auto related
• Leading cause of death for ages 1-40
• One-third are preventable
• Cost exceeds $220 billion (2001)
• Unnecessary deaths are often caused by injuries
missed because of low index of suspicion
Kinematics
• Physics of Trauma
• Understanding kinematics allows prediction of
injuries based on forces and motion involved in
an injury event.
Basic Principles
• Conservation of Energy Law
• Newton’s First Law of Motion
• Newton’s Second Law of Motion
• Kinetic Energy
Newton’s First Law
• Body in motion
stays in motion
unless acted on by
outside force
• Body at rest stays at
rest unless acted on
by outside force
Newton’s Second Law
• Force of an object = mass (weight) x
acceleration or deceleration (change in
velocity)
• Major factor is velocity
• “Speed Kills”
Law of Conservation of Energy
• For every action there is an opposite
and equal reaction
• Energy cannot be created or destroyed
• Energy can only change from one form
to another
Kinetic Energy
• Energy of Motion
• Kinetic energy = ½ mass of an object X
(velocity)2
• Injury doubles when weight doubles but
quadruples when velocity doubles
So…
When a moving body is acted on by an
outside force and changes its motion,
then kinetic energy must change to
some other form of energy.
If the moving body is a human being and
the energy transfer occurs too rapidly,
then trauma results.
Blunt Force Trauma
• Force without
penetration
• “Unseen
injuries”
• Cavitation
towards or
away from the
injury
Penetrating Trauma
• Piercing or
penetration of
body with
damage to soft
tissues and
organs
• Depth of injury
Mechanism of Injury Profiles
Motor Vehicle Collisions
• Five major types of motor vehicle
collisions:
– Head-on
– Rear-end
– Lateral
– Rotational
– Roll-over
Motor Vehicle Collisions
• In each collision, three impacts occur:
– Vehicle
– Occupants
– Occupant organs
Head-On Collision
Head-on Collision
• Vehicle stops
• Occupants continue forward
• Two pathways
– Down and under
– Up and over
Frontal Collision
• Down and under pathway
– Knees impact dash, causing knee
dislocation/patella fracture
– Force fractures femur, hip, posterior rim of
acetabulum (hip socket)
– Pelvic injuries kill!
Frontal Collision
• Down and under pathway
– Upper body hits steering wheel
• Broken ribs
• Flail chest
• Pulmonary/myocardial contusion
• Ruptured liver/spleen
Frontal Collision
• Down and under pathway
– Paper bag pneumothorax
– Aortic tear from deceleration
– Head thrown forward
• C-spine injury
• Tracheal injury
Frontal Collision
• Up and over pathway
– Chest/abdomen hit steering wheel
• Rib fractures/flail chest
• Cardiac/pulmonary contusions/aortic
tears
• Abdominal organ rupture
• Diaphragm rupture
• Liver/mesenteric lacerations
Frontal Collision
• Up and over pathway
– Head impacts windshield
• Scalp lacerations
• Skull fractures
• Cerebral contusions/hemorrhages
– C-spine fracture
Rear-end Collision
Rear-end Collision
• Car (and everything touching it) moves
forward
• Body moves, head does not, causing whiplash
• Vehicle may strike other object causing frontal
impact
• Worst patients in vehicles with two impacts
Lateral Collision
Lateral Collision
• Car appears to move from under patient
• Patient moves toward point of impact
• Increased potential for “shearing” injuries
• Increased cervical spine injury
Lateral Collision
• Chest hits door
– Lateral rib fractures
– Lateral flail chest
– Pulmonary contusion
– Abdominal solid organ rupture
• Suspect upper extremity fractures and
dislocations
Lateral Collision
• Hip hits door
– Head of femur driven through acetabulum
– Pelvic fractures
• C-spine injury
• Head injury
Rotational Collision
Rotational Collision
• Off-center impact
• Car rotates around impact point
• Patients thrown toward impact point
• Injuries combination of head-on, lateral
• Point of greatest damage =
point of greatest
deceleration = worst patients
Rollover
Roll-Over
• Multiple impacts each time vehicle
rolls
• Injuries unpredictable
• Assume presence of severe injury
• Justification for Transport to Level I
or II Trauma Center
Restrained vs Unrestrained
Patients
• Ejection causes 27% of motor vehicle collision
deaths
• 1 in 13 suffers a spinal injury
• Probability of death increases six-fold
Restrained with Improper
Positioning
• Seatbelts Above Iliac Crest
– Compression injuries to abdominal
organs
– T12 - L2 compression fractures
• Seatbelts Too Low
– Hip dislocations
Restrained with Improper Positioning
• Seatbelts Alone
– Head, C-Spine, Maxillofacial injuries
• Shoulder Straps Alone
– Neck injuries
– Decapitation
Motorcycle Collisions
• Rider impacts
motorcycle parts
• Rider ejected over
motorcycle or
trapped between
motorcycle and
vehicle
• No protection from
effects of
deceleration
• Limited protection from
gear
Pedestrian vs. Vehicle
• Child
– Faces oncoming vehicle
– Waddell’s Triad
• Bumper
• Hood
• Ground
Femur fracture
Chest injuries
Head injuries
Pedestrian vs. Vehicle
• Adult
– Turns from oncoming vehicle
– O’Donohue’s Triad
• Bumper
• Hood
Tib-fib fracture
Knee injuries
Femur/pelvic
Falls
• Critical Factor
– Height
• Increased height + Increased injury
– Surface
• Type of impact surface increases injury
– Objects struck during fall
– Body part of first impact
• Feet
• Head Buttocks
• Parallel
Falls
• Assess body part that impacts first, usually
sustains the bulk of injury
• Think about the path of energy through body
and what other organs/systems could be
impacted (index of suspicion)
Falls onto Head/Spine
• Injuries may not
be obvious
• C-spine
precautions!
• Watch for
delayed head
injury S/S
Falls onto Hands
• Bilateral colles
fractures
• Potential for
radial/ulna
fractures and
dislocations
Fall onto Buttocks
• Pelvic fracture
• Coccygeal (tail
bone) fracture
• Lumbar
compression
fracture
Fall onto Feet*
• Don Juan
Syndrome
– Bilateral heel
fractures
– Compression
fractures of
vertebrae
– Bilateral Colles’
fractures
Index of Suspicion
Stab Wounds
• Damage confined to wound track
– Four-inch object can produce nine-inch
track
• Gender of attacker
– Males stab up; Females stab down
• Evaluate for multiple wounds
– Check back, flanks, buttocks
Stab Wounds
• Chest/abdomen overlap
– Chest below 4th ICS = Abdomen until
proven otherwise
– Abdomen above iliac crests = Chest
until proven otherwise
Stabbings
• Always maintain
high degree of
suspicion with
stab wounds
• Remember: small
stab wounds do
NOT mean small
damage
Gunshot Wounds
• Damage CANNOT be determined by
location of entrance/exit wounds
– Missiles tumble
– Secondary missiles from bone impacts
– Remote damage from
• Blast effect
• Cavitation
Gunshot Wounds
• Severity cannot
be evaluated in
the field or
Emergency
Department
• Severity can only
be evaluated in
OR
Significant ALS MOI
• Multi-system trauma
• Fractures in more than one location
• MVA – death in same vehicle, high speed or
significant vehicle damage
• Falls > 2 X body height
• Thrown > 10 – 15 feet
• Penetrating trauma to the “box”
• Age co-factors: < 6 or > 60
• “Lucky Victim”
Conclusion
• Think about mechanisms of injury
• Always maintain an increased index of
suspicion
• Doing YOUR job as an EMT will lead to:
– Fewer missed injuries
– Increased patient survival