Quantum Physics and the Time-Space 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 Femur fracture

• Hood Chest injuries

• Ground Head injuries

Pedestrian vs. Vehicle

Adult

–Turns from oncoming vehicle

–O’Donohue’s Triad

• Bumper Tib-fib fracture Knee injuries

• Hood 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