Chapter 2 - Blunt Trauma Flashcards
1
Q
Blunt Trauma
A
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
2
Q
Kinetics
A
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
3
Q
Inertia
A
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
4
Q
Energy & Energy Conservation
A
pg 19
- Energy is defined as the ability to do work
- Energy can neither be created or destroyed
5
Q
Force
A
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
6
Q
Kinetic Energy
A
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
7
Q
Biomechanics of Trauma
A
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
8
Q
Compression Injury
A
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.
9
Q
Stretch Injury
A
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)
10
Q
Shear Injury
A
pg22
- occurs alon the edges of the impacting force or at organ attachments
11
Q
Vehicular collisions
A
pg 22
- 34,500 deaths annually
- Events of impact - 4 major collisions in MVA
- Vehicle Collision
- Body Collision
- Organ Collision
- Secondary Collisions
- *Additional Impacts
12
Q
Vehicle Collision
A
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
13
Q
Body Collision
A
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
14
Q
Organ Collision
A
pg 23
- Occurs as occupants body collides and tissues within body collide into one another
- Causes compression, stretching, tearing and shearing.
15
Q
Secondary Collisions
A
pg 24
- occurs when vehicle occupant is impacted my objects traveling within vehicle
- objects continue to trave at vehicles initial speed
16
Q
Additional Impacts
A
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
17
Q
Restraints: Seat Belts
A
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
18
Q
Restraints: Supplemental Restraint Systems (SRS)
A
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
19
Q
Restraints: Child Safety Seats
A
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
20
Q
Restraints: Head Rests
A
pg 25
- designed to prevent unopposed reward motion during rear-end collision
- protects agains violent backward head rotation and neck extention - Whiplash injury
21
Q
Restraints: Intrusion
A
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
22
Q
Types of auto impacts
A
pg 26
Frontal - 62%
Lateral - 23% - higer mortality rate
Rear-End - 7%
23
Q
Collision: 4 Modes of patient travel
A
pg26
- restrained
- up and over
- down and under
- ejection
24
Q
Restrained
A
pg 26
- lap and shoulder belts help occupant decelerate with the vehicle
- Limits interior impact and energy associated with it
25
Q
Up-and-over Pathway
A
pg 26
- occupant tenses legs in prep. for impact causing upper body to pivot forward and up
- steering wheel can cause femur fx
- steering wheel decelerates abdominal contents causing hollow-organ rupture and liver laceration
- increased abdominal pressure can cause diaphram to rupture
- lower chest may fx and become flail
- head impacts windshield = soft tissue, facial fx’s, and internal bleeding
- head striking windshield may result in hyperextention/hyper flexion or axial loading - as Cervical vertebrae collapse or compress
- a large proportion of vehicular deaths are attributed to up and over
26
Q
Axial Loading
A
pg 26
compression force on the c-spine resulting in collapse of vertebral column support elements
27
Q
Down-and-under Pathway
A
pg 26
- unrestrained occupant slides downward as vehicle comes to stop
- knees striking dash absorb initial impact resulting in knee, femur, hip dislocations and fractures
- Upper body then contact the lower steering wheel (higher on chest than up-and over)
- Resulting injuries: flail chest, blunt cardiac trauma, aortic tears
- If neck strikes steering wheel, tracheal and vascular injury may result
- Paper-Bag Syndrome may cause pneumothorax and pulmonary contusion
28
Q
Paper Bag Syndrome
A
pg 26
- As driver antipates impact they takes deep breath
- during collision aschest strikes steering wheel, pressure in chest results from compression of chest.
- resulting in pneumothorax and pulmonary contusions
29
Q
Ejection
A
pg 27
- The up and over pathway may lead to ejection of unrestrained occupant
- victim experiences two impacts:
- contact with interior of vehicle
- impact with environment
- responsible for 27% of vehicular deaths
- most commonly associated with frontal impact of unrestrained occupant
30
Q
Crumple Zone
A
pg 28
- modern vehicle design to absorb impact forces
- collapse happens more gradually
- reduces forces expressed onto occupants
31
Q
Lateral Impact
A
pg 28
- “T-Bone” - 90 degree impact
- greater likelihood of intrusion
- higer percentage of fatality
- typical injuries
- clavical
- humerus
- pelvis
- femur
- lateral fx of ribs (instead of anterior)
- diphram rupture
- pulmonary contusion
- head turns toward impact, vertebrae fx due to rapid lateral, twisting motion
- skull strikes side window
- splenic injury to driver
- liver injury to passenger
- heart like head, due to poor attachment in thoracic cavity, moves toward impact, can cause Aortic dissection or delamination of intima
32
Q
Oblique Impacts
A
pg 28
- vehicle is struck at an angle: left-front, right-front, right-rear, left-rear
- most likely to induce rotation
- injuries are generally less serious due to deflection
33
Q
Rear End Impact
A
pg 28
- collision force pushes the auto forward
- body propells forward with vehicle; neck rotates backward; when vehicle comes to rest, neck snaps forward creating “whip-lash” injury
- proper placement of head rest mitigates backward snapping motion
- improper placement of head rest can cause extreme hyperextension and hyperflexion
34
Q
Roll-Over Impact
A
pg 28
- normally caused by change in elevation or affecting vehicles with high centers of gravity
- commonly results in ejection or partial ejection of occupants
- initial injuries are compounded by subsequent impacts
35
Q
Vehicle Collision Analysis
Scene Hazards
A
pg 30
- vehicle hazards : oil, hot fluids, caustic substances, jagged objects, gasoline
- traffic, weather
36
Q
Vehicle Collision Analysis : Hybrid Vehicles
A
pg 30
- risk of electrocution: current ranges between 36 & 550 volts
- unexpected movement: silent electric propulsion may engage - remove proximity FOB (>16ft) or ensure ignition is off
37
Q
Vehicle Collision: Evaluate factors
A
pg 31
- determine:
- relative sizes of impacting vehicles or objects
- intrusion
- occupant interior impacts
- deformed steering wheel
- dented dash
- deformities of pedals = feet ankle injuries
- restraints used
- position of head rests
38
Q
Vehicle collision analysis: intoxication
A
pg 31
- consider possibility of drugs or alcohol
- 50% of fatals involve intoxication
- may be hard to differentiate between AMS and intoxication
- evidence of attempt to stop?
39
Q
Blunt Trauma to head and body cavity accounts for ___% of vehiculat mortality.
A
pg 31
85%
pay particular attention to ABC’s
look carefully at areas where your index of suspicion suggests injury
40
Q
Collision Evaluation
A
pg 32
- How did objects collide?
- From what direction did they come?
- What Speed were they traveling?
- Similar sized?
- Secondary Collisions?
- Wet pavement/poor visibility?
- Drugs/Alcohol?
- Skidmarks?
- Windshield? Bloody/star shaped? Penetrated by patients head?
- Steering Wheel Collapsed/deformed?
- Dash Dented?
- Intrusion
- Seatbelts/SRS systems/Head rests?
41
Q
Motorcycle Collisions
A
pg 32
- Frontal - head on
- Bike dips down, throwing rider up and forward
- handlebars catch lower abdomen/pelvis; femur fx wehn higher trajectory
- Angular - oblique angle
- riders lower extremity is trapped between bike and object struck
- can result in crushed or open wounds to femur, knee, ankle or foot
- Sliding - lays bike down (experienced rider)
- bike absorbs initial impact
- reduces chance of ejection
- increased abrasions, minor lacerations
- Ejection - commonly most serious
- injuries due to collisions with bike, object, ground
42
Q
Motorcycle injuries
A
pg 33
Likely injuries:
- skull/head injury
- spinal fractures
- paralysis
- internal thoracic
- abdominal injury
- extremity fxs
Protective equiptment
- helmets reduce incidence and severity by 50%
- leathers protect against soft tissue injuries, but hide underlying contusions, fxs, and internal injuries
43
Q
Pedestrian Collisions: Adult vs Pedi
A
pg 33
Adults
- Adults turn away - laterally to oncoming vehicle
- Initial Impact is low on body resulting in tib/fib fxs,
- Legs then displaced resulting in lateral knee ligamental injuries
- Lateral upper body crashes onto hood resulting in femur fx’s, lateral chest injuries, and upper extremity injuries
- Victim then slides up toward windshield where possible head, neck, and shoulder injuries.
- Further injuries or complications of other injuries may be caused by striking ground
Pedi
- children typically turn toward the vehicle
- injuries higher up on body; bumper strikes femurs or pelvis
- due to lower center of gravity children are usually thrown infront of the vehicle and run over or pushed to the side
- if child is thrown upward injuries will be similar to an adult
44
Q
Off Road Collisions : Snowmobiles
A
pg 34
- injuries similar to autos but with out restrain systems
- limited crumple zones for impact absorption
- typically result in
- ejection
- crush - secondary to rollover
- glancing blows from obstructions
- head & neck trauma from hidden wires
- collisions with autos, other snowmobiles, stumps or rocks
- Trauma often complicated by cold exposure and hypothermia
45
Q
Off Road Collisions : Watercraft
A
pg 34
- typically result of impact with other watercraft or obstructions
- not designed to absorb impact or provide passenger restraint
- serious injuries despite lower speeds than autos
- potential for complications due to drowning, boat sinking and hypothermia (water draws heat from body 20x faster than air
46
Q
Off road collisions : ATV’s
A
pg 34
- injuries similar to motorcycles and snowmobiles
- inexperienced riders
- capeability to travel off-road at fast speeds
- high center of gravity = likelihood of roll over
- expected injuries include:
- upper/lower extremity fxs
- head & spine injury
47
Q
Falls
A
pg 34
- most common form of blunt trauma
- increased risk in young or elderly
- a fall is the release of stored gravitational energy
- Newton’s second law: the more rapid the deceleration the greater the force and resulting injury
- Feet first falls transfer energy through: calcaneus, tiba, femur, pelvis, lumbar spine
- the lumbar spine is especially prone because it is the only skeletal component suporting the entire upper body
- If person attemps to break fall with outstretched arm injuries may include
- wrist, choulder, and clavicle injuries
- A backward fall may result in
- pelvic, thoracic, or head injury
48
Q
Severe Falls
A
pg 35
- classified as a fall of 3x heigth
- 20 feet in adults
- 10 feet in children
- focus attention of potential internal injuries; rapid decelleration causes organs to be compressed, displaced, and twisted
- ie ligamentum arteriosum rupture = exsanguination
49
Q
Criteria for evaluating a fall
A
pg 35
- determine
- fall heigth
- anatomic point of impact
- force of impact
- impact surface
- transmission pathway of forces through skeleton
- Anticipate
- fracture sites
- possible internal injuries
50
Q
Geriatric fall considerations
A
pg 35
- increased age =
- decreased coordination
- deficits
- eyesight
- muscle & bone strength
- bones may break during normal activities
- sometimes a break may cause a fall; rather than a fall that causes a break
- Consider circumstances of fall and patients preexisting medical conditions
51
Q
Blast Injuries : Explosion
A
pg 35
- occurs when an agent or environment combusts
- Conventional explosion = fuel and oxidizing agent combine instantaneously
- Heat from the breakdown/restablisment of chemical bonds creates a pressure differential between agent and surrounding air.
- This heat & pressure differential produces several MOI
- pressure wave
- blast wind
- projectiles
- displacement of persons near blast
- heat
52
Q
Pressure wave
A
pg 36
- As combustible agent ignites it superheats surrounding air, increasing the pressure of the exploding cloud
- The rapid increase in pressure compresses adjacent air, repeating as it gets further away from ignition point creating a pressure wave.
- This thin wave (blast overpressure, moves slightly faster than speed of sound) results in breif but drastic increase then decrease in air pressure
- When explosion occurs in confined space, ie bus, or interior of building, confined space aids in rapid pressure release and enhances potential for injury and death
- Water is a noncompressible medium that transmitts the blast overpressure efficently and aids in compression, decompression injuries, (water increases lethal range of blast 3 fold
- overpressure does not affect fluid or sold organs, however it does compress/decompress air in air filled organs
- eardrums/bowels, sinuses, and lungs
- as well as TBI
- Lying on ground with feet toward blast will aid in lessening effects of pressure wave
*
53
Q
Blast Wind
A
pg 37
- travels just behind pressure wave
- lasts longer than pressure wave
- outward mvmt of air and gases from epicenter
- causes much less damage but may displace debris or victims
54
Q
Projectiles
A
pg 37
- military ordnance, pipe bomb or container that bursts apart form during an explosion
- flechettes on military missles and ordnance help keep the projectile on-track
- IED’s are often filled with scraps of metal, nails, ballbearings, and screws that become projectiles when blast takes place
- debris from a blast may be powerful enough to remove limbs or cause serious open wounds
55
Q
Personnel Displacement
A
pg 37
- The overpressure and blast wave may be powerful enough to physically propel victims away from the blast’s epicenter
- Personnel then become projectiles which seffer blunt and penetrating trauma from impact with ground, other objects, debris or other o personnel
56
Q
Confined Space Explosions & Structural Collapse
A
pg37
- because the pressure wave radiates outward in all directions, the energy disipates quickly
- in a confined space, because pressure wave is contained, it maintains it’s energy longer
- pressure waves are reflected off surfaces and when they meet overpressure greatly increases
- the structure also adds debris and collapse elements to the explosion resulting in penetrating, blunt and crush injuries
- structural collapse makes extrication difficult for rescuers and difficult to locate victims
- additional hazzards include: additional collapse, electrocution, fire, secondary explosion of leaking gas or fuel.
57
Q
Burns
A
pg 38
- explosions produce tremendous heat
- flash burns for those close to detonation may produce superficial or partial thickness burns
- blast may ignite combustable materials such as clothing and and debris which are typically more extensive burns
58
Q
Types of Blast Injuries
Primary
A
pg 38
- primary blast injuries are caused by the heat of the explosion and the overpressure weave
- pressure injuries are the most serious and life-threatening because they damage air filled spaces: ears, sinuses, bowel, and lungs
- burns are limited unless caused by a secondary combustion (clothes or fuels collateral to the blast)
