1. Chapter 17 Blunt Trauma

2. Topics Introduction to Blunt Trauma Kinetics of Blunt Trauma
Types of Trauma
Blunt Trauma
Explosion
Other Blunt Trauma

3. Introduction to Blunt Trauma
Most common cause of trauma death and disability
Energy exchange between an object and the human body, without intrusion through the skin
Read
 crushing and stretching of structures -> injury beneath the surface

4. Blunt trauma can be deceptive because the true nature of the injury is often hidden and evidence of the serious injury is very subtle or even absent.
Read
That is why MOI is very important and a good predictor of injury  index of suspician

5. Kinetics of Blunt Trauma
Inertia
“A body in motion will remain in motion unless acted upon by an outside force.”
“A body at rest will remain at rest unless acted upon by an outside force.”
Conservation of Energy
“Energy can neither be created nor destroyed. It is only changed from one form to another.”
Kinetic versus Potential Energy
$ Kinetics = branch of physics that deals with forces affecting objects in motion and the E exchange when objects collide
$ inertia and conservation of E are 2 important concepts
Inertia
Newtons 1st law Eg: car into a tree, broadside collision changes cars directions
Other half of the first law Eg: rear end collision into a stopped vehicle
Conservation of E
So……when a car with Kinetic E comes to a quick stop, the E is transferred to the occupants. Same with a bullet entering a body.
Car braking transfers E to the brakes and heat due to friction
KE is the E of motion. Relates to objects mass and velocity . PE is an object that can gain E. Eg heat, motion.

6. Kinetics of Blunt Trauma
Kinetic Energy
Energy in Motion
Double Weight = Double Energy
Double Speed = Quadruple Energy
SPEED IS THE GREATEST DETERMINANT
Read KE= ½ MV 2
Mass = measure of the matter that an object contains
Velocity = rate of motion in a particular direction
Triple the speed  9 times the E and damage

7. Kinetics of Blunt Trauma
Force
Emphasizes the importance of rate at which an object changes speed (acceleration or deceleration)
Newtons 2nd law
Acceleration can also be negative = deceleration : both are rate at which an object changes speed.
Deceleration from braking is low  lower force
Deceleration from hit wall is high  higher force

8. Types of Trauma Blunt Penetrating Closed injury
Indirect injury to underlying structures
Transmission of energy into the body
Tearing of muscle, vessels and bone
Rupture of solid and hollow organs
Organ injury
Ligamentum teres
Aorta tear
Penetrating
Open injury
Direct injury to underlying structures
Blunt
Vs open injury due to penetration
Damage is due to the E transfer, not from the object itself
Read
Spleen, Bowels, Lungs. ASK class what they think will happen with each of these organs ruptured
Liver
Liver can be sliced by the ligamentum teres that supports it (like wire cutter slicing cheese)
Aorta can tear and rupture due to E forces  severe shock or exanguination
Penetrating
Injury comes from the object doing direct damage and from E transfer (eg bullet)

9. Blunt Trauma: Automobile Crashes
44,000 people die each year on US highways
Events of Impact
Vehicle Collision
Body Collision
Organ Collision
Secondary Collisions
Objects inside vehicle strike occupant
Additional Injuries
Vehicle receives a second impact
MVC’s most common cause of blunt trauma. Lots of deaths. Lots of serious injuries, continuing disabilities
Also from falls, explosions, crush injuries and sports
5 events happen in any impact
Vehicle damage is a good indicator of forces experienced by the occupants. Force developed in the crash depends on the stopping distance.
= body inside the vehicle hits the vehicle or the seat belt. E transferred to the vehicle or tissue deformity
Body stops, but organs keep going until they stop or tear or rupture or twist
Read
Object hitting a passenger can be another body!
Can cause further injuries or aggrevate the initial injuries

10. Inertia and MVC’s

11. Blunt Trauma: Automobile Crashes
Restraints
Seatbelts
Occupant slows with the vehicle
Shoulder and Lap belts MUST be worn together
Airbags (SRS)
Reduce blunt chest trauma
Cause: Hand, Forearm, Facial Injury & Neck
Check for steering wheel deformity
Side Airbags
Child Safety Seats
Infants and Small Children: Rear facing
Older Child: Forward facing
Seatbelts
Important to know if passengers were wearing seatbelts or not.
Seatbelt increases the ‘ridedown” time. No seatbelt  body hits dash from full speed to stop
Otherwise ^ injuries. Body can slide under shoulder belt alone. Lap belt only  body folds, head and chest impacts vehicle. Can often see the shoulder strap mark on the chest!
Steering wheels and dashboard are labeled with SRS.
Again, adds to the “ridedown” time. Inflates and deflates very quickly
Glasses can compound the injuries. Powder can cause eye and lung irritation
Indicates potential injury to patient
Cars now beginning to have side airbags. In seats, headliners.
Critical in protecting kids. Must be used properly. It is astounding the number of kids you see in the parents laps or jumping around in the back seat.
Read

12. Blunt Trauma: Automobile Crashes
Types of Impact
Frontal: 32%
Lateral: 15%
Rotational: 38%
Left & Right – Front & Rear
Rear-end: 9%
Rollover: 6%
5 types of impact.
These numbers are for urban setting. ASK class how they think the numbers might change in rural setting?  ^ frontal

13. Frontal Impact Down-and-Under Up-and-Over Ejection
Knee, femur, and hip fracture
Chest trauma-Steering Wheel
Paper Bag Syndrome
Up-and-Over
Tenses legs = Bilateral femur fracture
Hollow organ rupture and liver laceration
Similar chest trauma to down under
Axial Loading
Ejection
Due to up-and-over pathway
Contact with the vehicle & external object
$ 3 pathways of patient travel
Down and under
Knees hit dash and firewall
Followed by upper body collision with steering wheel  flail chest, cardiac contusion, torn aorta
Pt takes a breath if anticipating impact. Full lungs burst like a paper bag being smacked
Up and over
As body flexes and rises, femurs hit steering wheel
Due to compression by steering wheel. Diaphragm can rupture  mixing of thoracic and abdominal contents
Due to head into windshield  soft tissue, skull, facial and brain injuries. Also neck injuries due to body weight pushing on head and neck  deforms vertebral column, discs, spinal cord.
Due to passenger being unrestrained.
A continuation of the up and over or from roll over.
Read

14. Lateral Impact 15% of MVC’s but 22% of deaths Upper extremity injury
Rib, clavicle, humerus, pelvis, femur fracture, skull and brain
Lateral compression
Ruptured diaphragm, Spleen fracture, Aortic injury
EVALUATE the unrestrained occupant on opposite side
$ Less vehicle structure between impact site and vehicle interior. Less crumple zone  damage does not look as great so don’t under estimate the forces involved.
Read
More upper extremity and torso injuries
Read. Head into side of window
Read. Remember secondary the body collision.

15. Other Types of Crashes Rotational Rear-end Rollover
Vehicle struck at oblique angle
Less serious injuries unless strike a secondary object
Rear-end
Seat propels the occupant forward
Head is forced backwards, then forwards
Stretching of neck muscles and ligaments
Hyperextension & hyperflexion
Rollover
Multiple points of impact
Ejection or partial ejection
Less injury with restraints
Rotational
 car to veer from initial path. No instant stops.
Stopping distance greater, ^ ridedown time
Rear end
Body first pushed into seat back, then propelled forward
“whiplash”
Read
Read. Also can cause cervical vertebra and spinal cord damage in the extreme.
Rollover
Less vehicle padding on sides and roof
REad

16. Blunt Trauma: Automobile Crashes
Vehicle Crash Analysis
Hazards
Crumple Zones
Intrusion
Deformity of Vehicle
Use of Restraints and airbags
Intoxication
LOA, Head Injury, Pain sensation,
Fatal Accidents: >50% involved ETOH
Recreational Accidents
Crash Analysis
Glass, gas, wires, fire, sharp metal, battery acid. Other Traffic! Keep the defib off the road!
Front and back. Vehicle looks way worse these days. Side and roll overs don’t have the crumple zones so damage can look less and be worse for the patient.
Also look at what hit what – sizes, strength etc
See how far vehicle interior intrudes into the passenger compartment. My scene with the school bus bumper though the windshield.
Outside and inside. Dash and knobs, windshield, steering wheel, headrests and seats, pedals, firewall
More safety features limit injuries, but still be suspicious!!!
Do not let alcohol affect how you treat the patient! There have be many documented cases where medics, police etc have biases that affect their judgement and ultimately their treatment
Alcohol can impair your ability to assess accurately. Often patients who HBD, are often injured less. They just bounce around more.
Read
Eg: boating, snowmobiles, diving, kids climbing trees : lots of weird MOI’s

17. Vehicular Mortality Head: 48% Internal (Torso): 37%
Spinal & Chest fracture: 8%
Extremity fracture: 2%
All Other: 5%
Note that 85% are Head, neck, chest, abdo !! Hence the primary assessment includes the rapid trauma assessment!!
Read x 5

18. Crash Evaluation Collision Questions Cause of Crash Auto Interior
How did collision occur?
Direction?
Speed?
Similar/Different sized?
Secondary collisions?
Cause of Crash
Weather & visibility?
Alcohol involved?
Skid marks?
Auto Interior
Starring of windshield?
Steering wheel deformity?
Dash deformity?
Intrusion?
Collision Questions
Read
Cause of Crash
ASK class why do we care about cause of crash Eg, skid marks???
ANS  For pt with chest pain and bent steering wheel, which came first? MI or chest into steering wheel. You will have scenes where the crash was caused by a medical event first.
Auto Interior

19. Motorcycle Crashes
Serious injuries can occur with high and low speed collision.
Types of Impact
Frontal
Angular
Sliding
Ejection
Initial Bike/Object Collision
Rider/Object
Rider/Ground
Often patient is thrown.
ASK class about what kind of injuries to expect if driver thrown.  ride down time can be much longer with less internal injuries, but Musc skel can be massive. HI’s are very common even with helmets. Neck and spinal injuries!
Types
Handlebars cause all sorts of injuries to hips, pelvis, femurs. Have to analyse what the patient hit other than the bike iteself
Read
Experienced rider “lays the bike down” Book says less likely for serious injuries. Not sure, since more likely to hit the object directly and stop faster. Hmmmmmm. You just never know!
Again really hard to predict injuries. Proper and fast assessment is crucial
Read x 3

20. Pedestrian Accidents Adults Children Adults turn away
Bumper strikes lower legs first
Victim rolls up and over and thrown
Children
Children turn toward
Femurs, Pelvis often injured
Thrown away or run over
$ big time difference in size of colliding objects! Try to determine the speed of the vehicle thought Hx gathering
Adults
 Lateral impact to the body
 tibia and fibula #’s
 upper torso injuries  into windshield  then secondary collision with the road.
You will see cases where the body goes through windshield and inside!
Kids
 frontal impact
Smaller kids  injuries higher up on body
Pushed to side or run over.

21. Recreational Vehicle Accidents
Lack structure and restraint system
Often are off road scenes
Types of Vehicles
Snowmobiles
Personal watercraft
ATV’s
Similar to motorcycles
Makes reaching and extrication an issue!
Often alcohol is involved !!!
Travel very fast now! Can hit trees, cars, other machines, cold water immersion, wire fences.
Hypothermia (out of water) can be an issue
Hit boats, docks, other PWC’s. Includes complication of drowning. Propellers from the bigger boat.
Inherently not a stable machine to ride and poor handling when speed is involved.

22. Blast Injuries Blast Injuries Explosion
Dust, Fumes, Explosive Compounds
Explosion
Fuel + Oxidant combine instantaneously
Heat & Pressure Wave
Huge range of magnitude in explosions: small fireworks to massive gas explosion
= some of the causes
Explosions
 creation of massive amounts of E
High pressure of exploding agent  low pressure of surroundings
Go to next slide for types of injuries

23. Explosion Pressure Wave Burns Projectiles Personal Displacement
Structural Collapse
Blast Wind
Burns
Projectiles
Personal Displacement
Blast Injury Phases
Primary: Heat of the explosion and pressure wave
Secondary: Trauma caused by projectiles
Tertiary: Personnel displacement and structural collapse
Book has all sorts of details on this – don’t need to worry about the physics of it. = Rapid increase in pressure due to heated air
If explosion is inside a container, container holds the pressure until is ruptures or collapses
Comes from rapid release of pressure as container ruptures
Get rapid compression then decompression of bodies air filled spaces. ASK class to name some of these spaces. Lungs, hollow organs, sinuses, middle ear, bowels.
Secondary wind which carries heated and combustion gases, debris.
Flash burns to body. Clothing can also ignite. Will talk more about burns later in sem
Container holding the explosive eventually rupture and send projectiles. EG: bullets, bomb casings, garage filled with fumes.
Injuries can be major like amputations or less serious but look awful as body is peppered with little objects that get impaled in skin, eyes etc.
Ie body is thrown!  all sorts of other possible injuries like pedestrian struck or motorcycle.
Read x 3. Primary is most serious.

24. Blast Injury Assessment
Be alert for secondary device
Initial scene size-up important
Establish Incident Command System (ICS)
Evaluate for secondary hazards
Injury Patterns
Rupture of Air or Fluid Filled Organs
Lung: Late manifestation (heat & pressure)
Hearing loss
Do not enter the scene unless you are told it is safe by other agencies!!!
Ditto! Your job is to take care of the patients and they are usually brought to you.
If you are first there, BE CAREFUL
Usually not your job.
Gas, glas, wires, fire, sharp debris,
This is what you worry about!
Lungs and other hollow organs
Lungs and breathing, along with airway are your priorities! Look listen and feel during assessment!. DCAP BTLS, auscultate.
Not life threatening but patient will need you to be calm and reassuring

25. Blast Injury Care Lungs Abdomen
Forceful compression and distortion of chest cavity
Compression and decompression
Pulmonary Embolism, Dyspnea, Hemoptysis, Pneumothorax
Oxygen and ventilation
Abdomen
Compression & Decompression
Release of bowel contents
Diaphragm rupture from pushing of organs up into thorax area
Lungs
Read
 Collapse of alveoli, pulmonary edema, bleeding
= Possible injuries
Standard treatment of any respiratory distress. Pneumo may be caused by you ventilating!
Abdomen and GI tract is air filled too!
 hemmorage
 infections (not an immediate threat)
This could affect respiratory efficiency  respiratory distress

26. Blast Injury Care Ears Penetrating Wounds Burns Initial Hearing Loss
Injury improves over time
Penetrating Wounds
Care as any serious open wound or impaled object
Burns
Treatment consistent with traditional management.
Eustachian tube can equalize pressures slowly, but not quickly as in explosion. Remember the ABC’s!! Don’t get distracted by the ear! It is not a priority.
Eardrum stretches or ruptures due to pressure. Pressure can also # little bones of inner ear.
Read
Again, focus on the primary assessment and treatment first
Remember back to soft tissue injuries and treatment !!
Another day!

27. Other Types of Blunt Trauma
Falls
Force = mass x acceleration(deceleration)
Stairs, Force, Surface
Landing Area
Surface Type
Body Part
Height of Fall
Elderly
Falls are a factor of height and deceleration. Body up high has lots of Potential Energy! Remember Gravity sucks!
Newtons 2nd law: force = mass x acceleration (deceleration)
It is not the fall that kills you, it is the sudden stop at the bottom!
All are factors affecting the E transmission through the body.
Same issue: All are factors affecting the E transmission through the body.
Hard vs soft affect amount of E transfer
Lots of different types of injuries depending on body part
Landing feet first transmits E along spine.
Fall forward tramits E along arms into wrists, arms, shoulders, clavicles
Can bite the tongue!
Diving hits head + rest of body compresses the c spine  2 injury patterns
Fall > 3 times the height of the person is serious 20 ft for adult, 10 for kids. Higher fall = more speed
As height increases move your index of suspicion to internal injuires!
Falls in the elderly are very common. Usually not high or fast, but their bones and structures are more brittle  lots of injuries. Hips and pelvis are very common.

28. Sports Injuries Various Injury Patterns
Produced by extreme exertion, fatigue or direct trauma
Acceleration, deceleration, compression, rotation, hyperextension, or hyperflexion
Unconsciousness, neurological defect or decreased mental status require physician follow-up
Protective Gear reduces injury pattern
Helmet Removal
Review musculo-skeletal injuries
Read
 #’s, tendon, ligament, connective tissue injuries. And Internal injuries!
Don’t let coach or player talk you out of transport!
Read. Will tech you in the lab. Sometimes the gear itself contributes to injuries eg, helmet can aggrevate neck injuries since adds weight to the head
If loose remove
If tight, remove face mask and immobilize in place
Take helmet to hospital

29. Crush Injuries Cause Great force to soft tissue and bones
Structural collapse, explosion, industrial, agricultural, vehicles
Great force to soft tissue and bones
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
Read
Read x 4

30. Summary Blunt Trauma Types Causes of Blunt Trauma Assessment of Injury
Injury Patterns