Blunt Trauma Flashcards
Law of Inertia
Tendency of an object to remain at rest or remain in motion unless acted upon by an outside force
– Car into tree
– Passenger collisions within a car
– Organ collisions within a body
During an auto crash, energy of mo/on converted into
– Sound of impact
– Deformation of the auto’s structure
– Heat in the twisted steel
– Physical injuries to the patient as they collide with the interior
Kinetic energy
• Energy of motion
– Function of object’s mass and velocity
• Speed is the greatest determinant of energy involved
Newton’s second law of motion
Emphasizes the importance of rate at which an object changes speed (acceleration or deceleration)
Blunt Trauma
– Occurs when a body is struck by or strikes an object
– Closed injury
– Transmission of energy injures underlying tissues and organs
• Tearing of muscle, vessels and bone
• Rupture of solid organs
• Organ injury
Penetrating Trauma
– Wounds that break the skin, energy source enters into body
– Low energy
• Knives
• Injury limited to the path of the weapon
– High energy
• Guns
• Energy may be transmitted to surrounding tissue, extending the trauma
Blunt traumas
- Explosions
- Falls
- Crush injuries
- Sporting injuries
Automobile Collisions
- Vehicle collision
- Body collision
- Organ collision
- Secondary collision
- Additional impacts
Restraints
• Profound effect in reducing collision-related deaths
• Seatbelts
– Occupant slows with vehicle
– Shoulder and lap belts should be worn together
• Injuries occur if they are worn separately
– EMS should model the behaviour
Restraints Airbags
– Reduce blunt chest trauma
– Cause: Hand, Forearm, & Facial Injury
– Check for steering wheel deformity
– Side Airbags
Restraints Child Safety Seats
– Provide the best protect for infants and small children riding in vehicles
– Infants and Small Children: Rear facing
– Older Child: Forward facing
Types of Impact
• Frontal: 32% • Lateral: 15% • Rotational: 38% – LeF & Right – Front & Rear • Rear-end: 9% • Rollover: 6%
Frontal Impact
• Most common type of impact
• Often result in significant exchange of energy and serious injuries
• Produces three pathways of occupant travel
– Down and under pathway
– Up and over pathway
– Ejection
Down and Under Pathway
• Occupant slides downward as vehicle comes to a stop
• Knees come into contact with firewall and absorb the initial impact
– Knee, femur, and hip fracture or dislocations
• Upper body rotates forward and hits steering wheel
– Chest trauma
• Driver may take a deep breath in anticpation of the impact
– Paper Bag Syndrome
Paper bag syndrom
Rupture of the lungs that occurs as the chest meets with blunt trauma after taking a deep breath, usually during a motor vehicle crash, similar to rupture of an air-filled paper bag.
Up and Over Pathway
• Occupant tenses legs in anticipation of the impact
• Upper body pivots forward and upward
• Steering wheel impinges on the femurs
– Possible bilateral fractures
– Compresses and injures abdominal contents
• Lower chest strikes steering wheel
– Thoracic injuries
• Forward motion propels head into windshield
– Head and neck injuries
– Axial loading
Ejection
• Due to up-and‐over pathway
• Victims experience two impacts
– Contact with vehicle interior and windshield
– Impact with ground, trees or other objects
• Responsible for 27% of vehicular fatalities
Crumple Zones
- Frontal impacts interpose more vehicle between the point of impact and patients
- Modern vehicles use this area to absorb impact forces and limit occupant injury
- Patients in collisions involving vans or lateral impacts do not benefit the same way
Lateral Impact
• 15% of MVC’s but 22% of deaths
• Kinetics the same as in a frontal impact
• Two exceptions:
– Occupants present a different profile
– Less structural steel to protect occupants
Lateral Impact
• Increased upper extremity injuries
– Lateral rib fractures
– Head and neck injuries
• Lateral compression
– Ruptured diaphragm, spleen fracture, aortic injury
• Consider any unrestrained passengers
– Becomes an object that will collide with driver
Rotational Impact
• Vehicle struck at oblique angle
• Energy exchange generally more gradual
– Deflected form path rather than stopped
– Longer stopping distance
– Deceleration more gradual
• Less serious injuries unless there are multiple impacts
Rear-End Collision
• Seat propels the occupant forward
– Generally good protection for the body
– Poor protection for the head
• Head is forced backwards and then forwards
– Stretching of neck muscles and ligaments
– Hyperextension & hyperflexion
Rollover
• Generally caused by:
– Change in elevation
– Vehicle with high centre of gravity
• Occupant experiences impact at each impact of vehicle
• Often involves ejection or partial ejection
• Injuries are usually compounded by multiple subsequent impacts
Vehicle Collision Analysis
- Hazards
- Crumple Zones
- Intrusion
- Deformity of Vehicle
- Use of Restraints
Hazards
• Heat
– Hot engine and transmission parts
– Hot fluids (radiator coolant, engine oil)
• Caustic substances
– Batery acid, automatic transmission fluid, steering fluids
• Sharp jagged edges of metal and broken glass
Intoxication
• 36.5% of deaths on Canadian Highways were alcohol related(2001 CCMTA statistics)
• Patient effects:
– Alters level of consciousness
– Masks signs and symptoms of injury
– Anesthetizes patient somewhat
• Makes mechanism of injury analysis and index of suspicion even more important
– Otherwise significant injuries may be missed
Collision Questions
– How did the objects collide?
– From which direction did they come?
– At what speed were they travelling?
– Were the object similarly or different sized?
– Were there any secondary collisions or additional transfers of energy?
Cause of Collision
– Did wet roads or poor visibility contribute to the crash?
– Was alcohol involved?
– Are ther skid marks? Was the driver prevented from braking?
Auto Interior Question
– Does the windshield show evidence of an impact?
– Is the steering wheel deformed or collapsed?
– Is the dash indented where the knees or head hit it?
– Has the impact extended into the passenger compartment?
Motorcycle Collisions
• OFen result in serious trauma even at low speed – Driver absorbs most of impact • Impacts – Frontal – Angular – Sliding – Ejection • Initial Bike/Object Collision • Rider/Object • Rider/Ground
Adult Pedestrian Accidents
– Adults turn away
– Bumper strikes lower legs first
– Victim rolls up and over and thrown
Child pedestrian accident
– Children turn toward
– Thrown in front of car
– Femurs, pelvis oFen injured
Recreational Vehicles
• Lack structure and restraint system – Little protection offered to occupants • Types of Vehicles – Snowmobiles – Personal watercraft – ATV’s
Blast Injuries
• Causes:
– Dust (e.g. grain elevator)
– Fumes (e.g. gasoline or natural gas)
– Explosive compounds
• Magnitude ranges from small fire cracker to a nuclear explosion
• May be accidental or an act ot terrorism
Mechanisms of a Blast
- Explosion
- Pressure wave
- Blast wind
- Projectiles
- Personnel displacement
- Confined space explosions and structural collapses
- Burns
Blast Injury Phases
• Primary
– Caused by heat of explosion and pressure wave
• Secondary
– Caused by blast projectiles
• Tertiary
– Caused by personnel displacement and structural collapse
Blast Injury Assessment
• Survey and assess scene
– Be aware of potential for secondary device
– Secure further EMS operations
• Triage
• Establish Incident Command System if necessary
• Evaluate for secondary hazards
Common Injuries Lungs
– Pressure wave rapidly compresses and distorts chest, lungs and alveoli
– Ruptures alveolar walls
– Fluid accumulation and hemorrhage
– High risk of emboli formation
Common injuries Abdomen
– Rapid compression and decompression
– Bowel wall may hemorrhage or rupture
– Release of bowel contents into abdomen
Common Injuries ears
– Eustachian tube cannot equalize pressure
– Stretching or rupture of tympanic membrane
– Often fracture of small bones of hearing
– Hearing loss may be temporary or permanent
Common injuries penetrating wounds
– Care as any serious open wound or impaled object
Common Injuries Burns
Treatment consistent with traditional management
Falls
• Release of stored gravitational energy
• Potential for injury depends on:
– Height
– Stopping distance
Fall Factors
• Nature of impact surface contour
– Stairway may focus force of impact , increasing seriousness of injury
• Area of contact and pathway of of energy transmission
– Energy transmitied up skeletal structure
• Age related factors
– Common problem in elderly
Sports Injuries
• Injuries most commonly produce by extreme exertion, fatigue or direct trauma
– Variety of injury patterns
– Often exchange of great kinetic forces producing serious injuries
• Alterations in patient LOC result in:
– Exclusion from further activity
– Follow up with a physician
Protective Gear
• Greatly reduces potential for injury
– May also cause injuries e.g. cleats may cause torn ligaments as the foot is fixed while the knee is twisted
• Helmet
– If loose remove
– If tight, remove face mask and immobilize in place
– Take helmet to hospital
Kinetics
Branch of physics dealing with: – Forces affecting objects in motion – Energy exchanges that occur as objects collide Two basic principles: – Law of inertia – Law of conservation of energy
Crush Injuries
• Causes
– Structural collapse, explosion, industrial; or agricultural
• Pathophysiology
– Tissue stretching and compression
– Extended pressure results in anaerobic metabolism distal to compression
– Return of blood flow, toxins to entire body
– Severe hemorrhage due to severe damaged blood vessels
