Transcript KINEMATICS

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
 Understanding
of Trauma
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 sixfold
Restrained with Improper
Positioning
 Seatbelts
Above Iliac Crest
– Compression
injuries to
abdominal organs
– T12 - L2 compression fractures
 Seatbelts
– Hip
Too Low
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