Chapter 2 - Blunt Trauma Flashcards
(146 cards)
Blunt Trauma
pg 18
- results from exchange of energy between object and human body, without intrusion of the object through the skin
- most common cause of trauma death and disability.
- energy exchange results in crush, tear, stretch injuries below the skins surface
Kinetics
pg 18
- branch of physics dealing with objects in motion and energy exchanges that occur as these onjects collide.
- The two basic principles of kinetics
- laws of inertia
- energy conversation
Inertia
pg 18
- Newtons first law
- bodies in motion will remain in motion unless acted upon by an outside force; bodies at rest will remain at rest unless acted upon by an outside force
Energy & Energy Conservation
pg 19
- Energy is defined as the ability to do work
- Energy can neither be created or destroyed
Force
pg 19
- Newton’s second law
- states that force strength is related to an objects weight (mass) and the rate of its change in velocity.
Force = Mass x Acceleration (or deceleration) / 2
Kinetic Energy
pg 19
- the energy of an object in motion
- it is a function of the objects mass and velocity.
KE = Mass(weight) x Velocity(speed)2 /2
Biomechanics of Trauma
pg 20
- is the investigation of the injury process
- examines kinetic energy forces as they progress from body’s exterior to the internal organs and structures
- bound by lawas of physics: inertia, force, and energy conservation
Compression Injury
pg 21
- occurs as blunt object abruptly halts a portion of the body while inertia causes the remaining anatomy to continue in motion
- results in one tissue or organ being pushed into another, compressing it and damaging small blood vessels, connective tissues, and cell structures within.
Stretch Injury
pg 21
- opposite of compression
- protein fobers that hold tissues together are pulled and injured or torn
- happens when tissues are pulled away from one another
- Hollow organs filled with fluid/air stretch laterally as pressure brings anterior and posterior walls of organ together (ie plastic bag under foot)
Shear Injury
pg22
- occurs alon the edges of the impacting force or at organ attachments
Vehicular collisions
pg 22
- 34,500 deaths annually
- Events of impact - 4 major collisions in MVA
- Vehicle Collision
- Body Collision
- Organ Collision
- Secondary Collisions
- *Additional Impacts
Vehicle Collision
pg 22
- begins when vehicle strikes (or is struck) by another object
- vehicles KE (kinetic Energy) causes damage as it converts to heat and mechanical energy
Body Collision
pg 23
- 2nd Collision in MVA
- occurs when occupants within vehicle strike interior of vehicle
- Occupants KE is transformed into initial tissue deformity
- restraints and safety features work to decelerate occupants and impact strength
Organ Collision
pg 23
- Occurs as occupants body collides and tissues within body collide into one another
- Causes compression, stretching, tearing and shearing.
Secondary Collisions
pg 24
- occurs when vehicle occupant is impacted my objects traveling within vehicle
- objects continue to trave at vehicles initial speed
Additional Impacts
pg 24
- occur when vehicle recieves a second impact
- can be from deflection into other objects or struck by other vehicles in the accident
- can cause new injuries or further the seriousness of those already recieved
Restraints: Seat Belts
pg 24
- prevents occupants continued independent movement during collision
- lessesns the chance for ejection
- helps slow occupants with vehicle
- if lap belt is worn too high, abdominal compression, and spinal fractures to T12 - L2 may result
- if worn too low - hip dislocation may take place
- does not provide protection for head and neck movement
Restraints: Supplemental Restraint Systems (SRS)
pg 24
- aka: Airbags
- extreemely effective for initial frontal collisions but not susequent/secondary collisions
- residue from airbag deployment may cause irritation but can be relieved with gentle irrigation
- always check for dash and steering wheel deformity
Restraints: Child Safety Seats
pg 25
- <2yrs children should be placed in rear seat facing backward
- >2yrs seated forward in mini seat facing forward
- children in adult’s lap are not protected during collision
Restraints: Head Rests
pg 25
- designed to prevent unopposed reward motion during rear-end collision
- protects agains violent backward head rotation and neck extention - Whiplash injury
Restraints: Intrusion
pg26
- Intrusion suggests increased KE may have reached the patient
- Intrusion associated with lateral impact is frequent due to reduced crumple zone
- Lateral impact has very high occupant mortality
Types of auto impacts
pg 26
Frontal - 62%
Lateral - 23% - higer mortality rate
Rear-End - 7%
Collision: 4 Modes of patient travel
pg26
- restrained
- up and over
- down and under
- ejection
Restrained
pg 26
- lap and shoulder belts help occupant decelerate with the vehicle
- Limits interior impact and energy associated with it