SLIDE 1:
Crash Assessment for Field Triage
Rules and Exceptions
Stewart Wang, M.D., Ph.D.
University of Michigan
Trauma Burn Center
Joel MacWilliams
University of Michigan
Transportation Research Institute
[presented]
University of Maryland
Baltimore, Maryland
November 4, 20004
SLIDE 2:
[CIREN map]
SLIDE 3:
[unidentified photo of trauma copters landing]
SLIDE 4:
University of Michigan
Transportation Research Institute
[photos of crash test dummies/ sleds/ building exterior UMTRI
SLIDE 5:
Motor Vehicle Crashes
 * 1,000,000 deaths per year worldwide
 * No. 4 global health problem by the year 2020  W.H.O.
SLIDE 6:
Crashes in the USA
 ~40,000 killed (115/day, 1/13 minutes)
 ~3,000,000 injured
 ~$230 Billion
SLIDE 7:
Riding in a car continues to be the most dangerous thing you do on a daily basis
SLIDE 8:
ABCs of Vehicle Assessment
SLIDE 9:
ABCs of Vehicle Assessment
A is for Angle or more precisely Principle Direction of Force (PDOF)
SLIDE 10:
ABCs of Vehicle Assessment
A is for Angle or more precisely Principle Direction of Force (PDOF)
 Why is PDOF important?
SLIDE 11:
PDOF and Occupant Response
Occupant Response is equal and opposite to the PDOF
SLIDE 12:
ABCs of Vehicle Assessment
Newtons Third Law of Motion..
For every action (force) in nature, there is an equal and opposite reaction
SLIDE 13:
ABCs of Vehicle Assessment
.which tells us the patients
 likely path of travel,
 side of body likely injured,
 the parts of the vehicle that are likely injury sources, and
 the direction from which unsecured cargo and/or unrestrained occupants may have struck the patient from the backside of the PDOF
SLIDE 14:
ABCs of Vehicle Assessment
Remember
 The other occupants in the vehicle (injured or not) often interact during the crash sequence and can be the source of a patients injury
SLIDE 15:
ABCs of Vehicle Assessment
Remember
 The other occupants in the vehicle (injured or not) often interact during the crash sequence and can be the source of a patients injury
 Unsecured cargo is also a potential injury source - e.g. text books, portable DVD players,
golf clubs, softball equipment, water heaters,
laptops, bowling balls, etc.
SLIDE 16:
ABCs of Vehicle Assessment
 How to quickly assess the PDOF of a given vehicle
SLIDE 17:
Quick Assessment of PDOF
The Superman technique
- if you could grab a piece of the vehicle with one finger and pull in one direction, what direction would you pull in order to restore the car to its original shape
SLIDES 18-20:
[post-crash overhead shots of exterior crushed vehicles. arrows indicates likely direction of PDOF]
SLIDE 21:
ABCs of Vehicle Assessment
 Precision is not required
 An oclock interpretation is sufficient
SLIDE 22:
OCLOCK / PDOF
[clock-face diagram illustrating the "o'clock" interpretation of a PDOF]
SLIDE 23:
ABCs of Vehicle Assessment
B is for Belts & Bags
SLIDE 24:
Field Assessment of Belt Use
 Seatbelt D-rings
 Seatbelt Continuous Loops
 Seatbelt webbing
 Seatbelt load limiters
 Seatbelt post-crash modes
   Locked in extended or retracted position
   Webbing cut with tongue in buckle
   Webbing cut without tongue in buckle
 Steering-wheel rim deformation
SLIDE 25:
D-rings
[photo close-ups]
SLIDE 26:
Continuous Loops
[photo close-up]
SLIDE 27:
Webbing Marks
[photo close-ups]
SLIDE 28-29:
Load Limiters
[photo close-ups]
SLIDE 30:
Post-Crash Belt Mode
- Belt locked in extended mode post-crash - will not retract
SLIDE 31:
Post-Crash Belt Mode
- Belt locked in retracted mode post-crash - will not extend
SLIDES 32-34:
Post-Crash Webbing Cut
[photo close-up]
SLIDE 35:
ABCs of Vehicle Assessment
 Loading evidence of belt systems is not always so grossly obvious
SLIDE 36:
[post-crash interior close-up of steering wheel deformation]
Lower SW rim deformation is usually indicative of an unbelted driver
SLIDE 37:
[post-crash interior close-up of steering wheel deformation]
Upper SW rim deformation is usually indicative of a belted driver
SLIDE 38:
[post-crash interior close-up of steering wheel deformation]
Upper AND lowerSW rim deformation tends to occur in higher severity crashes and can be a belted or unbelted driver
SLIDE 39:
ABCs of Vehicle Assessment
SLIDE 40:
ABCs of Vehicle Assessment
[interior post-crash photo showing driver & front passenger frontal airbag deployment
SLIDE 41:
ABCs of Vehicle Assessment
[interior post-crash photo showing driver side airbag deployment]
SLIDE 42:
ABCs of Vehicle Assessment
[interior post-crash photo showing driver's curtain style side airbag deployment]
SLIDE 43:
ABCs of Vehicle Assessment
[interior post-crash photo showing driver's airbag not completely deployed]
SLIDE 44:
ABCs of Vehicle Assessment
 Rule - belted occupants may still contact interior components in higher severity crashes
SLIDE 45:
ABCs of Vehicle Assessment
 Rule - belted occupants may still contact interior components in higher severity crashes
 Rule - in general, belt restrained occupants fare well in most crashes
SLIDE 46:
ABCs of Vehicle Assessment
 Rule - belted occupants may still contact interior components in higher severity crashes
 Rule - in general, belt restrained occupants fare well in most crashes
 Exceptions - improperly belted, inappropriately belted, very young and the very old
SLIDE 47:
ABCs of Vehicle Assessment
 Rule - airbag restrained occupants generally enjoy good protection from head to abdomen
SLIDE 48:
ABCs of Vehicle Assessment
 Rule - airbag restrained occupants generally enjoy good protection from head to abdomen
 Exception - unbelted occupants can often miss or skip off the airbag (angled PDOFs)
SLIDE 49:
ABCs of Vehicle Assessment
 Rule - airbag restrained occupants generally enjoy good protection from head to abdomen
 Exception - unbelted occupants can often miss or skip off the airbag (angled PDOFs)
 Exception - occupants who are out-of-position (OOP) can sustain inflation injuries - eg flail chest, A-O separation, forearm fractures, brain injuries (angular acceleration)
SLIDE 50:
ABCs of Vehicle Assessment
C is for Crash Severity
SLIDE 51:
ABCs of Vehicle Assessment
Minor - Frontal
 * Minimal hood deformation
 * No wheelbase reduction
 * Appears driveable
SLIDE 52:
SLIDE 53:
ABCs of Vehicle Assessment
Moderate - Frontal
* Moderate hood deformation
* Typically not driveable
* Minimal or no wheelbase reduction
* Minimal intrusion; typically limited to floor/toepan
SLIDE 54:
ABCs of Vehicle Assessment
Moderate - Side
* 4-6 inches of door intrusion
* Minimal or no wheelbase  reduction
* Doors may be jammed but no entrapment (physically pinned by vehicle component)
SLIDE 55:
ABCs of Vehicle Assessment
Severe - Frontal
[post-crash exterior photo vehicle make/model unclear]
* Significant hood deformation
* Obvious wheelbase reduction
* Remote buckling of roof due to A-pillar movement
* Dash, floor, & steering column intrusion common
SLIDE 56:
ABCs of Vehicle Assessment
Severe - Side
[post crash exterior photo saturn sedan, impact to driver side]
* More than 6 inches of door intrusion
* Roof buckling
* Obvious wheelbase reduction
* Vehicle may bow (banana shape)
* Seat cushion & seat backrest deformation common
* Occupant entrapment (physically pinned) more common
SLIDE 57:
Vehicle Incompatibility/Aggressivity
Fatality Ratios from FARS
Car Front to Vehicle-X Left Side
Vehicle X / Fatality Ratio (Veh. XCar)
* car / 5.6
* SUV / 1.4
* Van / 1.1
* Pickup Truck / 1.1
SLIDE 58:
Vehicle Incompatibility/Aggressivity
Fatality Ratios from FARS
Vehicle-X Front to Passenger Car Left Side
Vehicle X / Fatality Ratio (Car/Veh. X)
* SUV / 30
* Van / 13
* Pickup Truck / 25
SLIDE 59:
ABCs of Vehicle Assessment
 Rule - injury probability increases as crash severity increases
SLIDE 60:
ABCs of Vehicle Assessment
 Rule - injury probability increases as crash severity increases
 Rule - near-side impacts have higher probability of injury than other crash modes (front, rear)
SLIDE 61:
ABCs of Vehicle Assessment
 Rule - injury probability increases as crash severity increases
 Rule - near-side impacts have higher probability of injury than other crash modes (front, rear)
 Exceptions - OOP, ejections, cargo, collision partner (mass or geometric incompatibility)
SLIDE 62:
ABCs of Vehicle Assessment
A is for Angle or more precisely Principle Direction of Force (PDOF)
B is for Belts & Bags
C is for Crash Severity
SLIDE 63:
ABCs of Occupant Assessment
Age
  Rule:  The extremes of age are more vulnerable to injury (and have decreased physiologic reserve)
SLIDES 64-65:
CASE #2
[post crash photo vehicle exterior]
3 Child Occupants: Ages 3,6 & 7
SLIDE 66:
Outcome
7 year-old right front passenger
   Bruises
   Atlanto-occipital dissociation
SLIDE 67:
[post crash photo - vehicle interior]
6 year old right rear passenger
  Shoulder belt behind back
  Lap belt slack
SLIDE 68:
Outcome
6 year-old right rear passenger
   Skull fracture and brain injuries
   Lumbar (L2,3,4) spine fractures
   Multiple intestinal injuries
   Atlanto-occipital dissociation (more severe)
SLIDE 69:
[post crash photo - vehicle interior]
3 year old right front passenger
Shoulder belt behind back
SLIDE 70:
Outcome
3 year-old left rear passenger
   Multiple intestinal injuries
   Pelvic fractures
   Atlanto-occipital dissociation (most severe)
SLIDE 71:
CASE II
1. Adult Driver
   No significant injuries
2. 7 year-old right front passenger
   Atlanto-occipital dissociation
3. 6 year-old right rear passenger
   Atlanto-occipital dissociation (more severe)
   Other injuries deleted
4. 3 year-old left rear passenger
   Atlanto-occipital dissociation (most severe)
   Other injuries deleted
SLIDE 72:
Risk of Injury to Children in Crashes
[bar chart]
Injury Risk:
Unrestrained -38% - Seat belt 59% - Booster seat
SLIDE 73:
[photo] Children Dont Fit Adult Seats
SLIDE 74:
Seat Belt Mispositioning
[graphics]
SLIDE 75:
Risk of Abdominal Injury for Child Occupants in Crashes 1999-2002
[bar chart]
SLIDE 76:
Involvement, Injury, and Fatality Rates (rates per vehicle miles of travel) [line chart]
SLIDE 77:
ABCs of Occupant Assessment
Age
  Rule:  The extremes of age are more vulnerable to injury (and have decreased physiologic reserve)
 - Exception: Children 3  8 fare poorly if not in belt-positioning booster seats.
Body Habitus
 Rule:  Size does matter  fat is protective.
SLIDES 78-88:
Obesity Trends* Among U.S. Adults
BRFSS, 1991 through 2001
BMI >/=30 or ~ 30lbs overweight for 5'4" woman
[US map]
SLIDE 89:
[CAD - driver impact to airbag at time of deployment
2 side view CTs - one normal body weight male, one heavy bodyweight male
SLIDE 90:
Study Methods
2 inch slab selected at L3
SLIDE 91:
Study Methods
SubQ and Visceral Fat selected and volumes measured
SLIDE 92:
All subjects: Correlation between fat volume and physical and outcome factors
[table]
SLIDE 93:
Increased Subcutaneous Fat Volume Is Associated With Decreased Abdominal Injury Severity
SLIDE 94:
[scattercharts]
Effect of SubQ FAT on Injury Severity in Frontal Crashes
Overall - Head - lower Extremity - Abdomin
SLIDE 95:
ABCs of Occupant Assessment
Age
  Rule:  The extremes of age are more vulnerable to injury (and have decreased physiologic reserve)
 - Exception: Children 3  8 fare poorly if not in belt-positioning booster seats.
Body Habitus
 Rule:  Size does matter  fat is protective.
 Exception:  Side impacts and LEX injuries
Complaints
 Rule:  Respiratory, neurologic, torso pain
 Exception:  Unable to complain
SLIDE 96:
Complaints
Respiratory
 Airway compromise, pneumothorax, hemothorax, flail chest, diaphragm rupture
 Secure airway and ventilation
Neurologic
 Spine, intracranial, cerebral-vascular
 Spine stabilization,
Torso pain
 Internal visceral injuries
 Chest decompression, access/volume, pelvic stabilization.
SLIDE 97:
Frontal Collisions- Torso Injuries
Lateral rib fractures
 Visceral Injuries evenly distributed
 Lung, liver, spleen
 Intestinal - seatbelt
 Pelvic fractures
 open book, posterior hip dislocation
SLIDE 98:
Side Impact Collisions- Torso Injuries
 Greater risk of injury than frontal
 Posterior rib fractures
 Struck side visceral injuries <lung, liver, spleen, kidney>
 Diaphragm and aortic injuries common  (Left)
 Pelvic fractures - central acetabular
Risk of chest, neck and head injuries increases with height of striking object
SLIDE 99:
ABCs of Occupant Assessment
Age
  Rule:  The extremes of age are more vulnerable to injury (and have decreased physiologic reserve)
 - Exception: Children 3  8 fare poorly if not in belt-positioning booster seats.
Body Habitus
 Rule:  Size does matter  fat is protective.
 Exception:  Side impacts and LEX injuries
Complaints
 Rule:  Respiratory, neurologic, torso pain
 Exception:  Unable to complain