0. International Trauma Life Support, 7e
Scene Size-up 1
Key Lecture Points
Explain the relationship of time to patient survival and how this affects our actions at the scene.
Explain the steps of the Scene Size-up and the importance of each step.
Explain the importance of being aware of mechanisms of injury.
Briefly review the concept of transfer of energy.
Stress the concept of the “three collisions.”
Briefly review the highlights of specific situations.
Large vehicle accidents
Frontal deceleration—effect on driver and passengers
Lateral impact
Rear impact
Rollover
Effect of restraints—lap belts, cross-chest lap belts, and air bags
Tractor accidents
Small vehicle accidents
Motorcycles
All-terrain vehicles
Personal watercraft
Snowmobiles
Pedestrian injuries
Falls
Penetrating injuries
Knives
Gunshot wounds
Blast injuries

1. Scene Size-up NOTE: Additional useful information can be found in:
Multicasualty Incidents and Triage in Additional Student Resources on Resource Central.
Trauma continues to be most expensive health problem in United States and most other countries.
In United States, trauma is fourth leading cause of death for all ages and leading cause of death for children and adults under age 45.
Cost of injury in United States is estimated to be twice that of cardiovascular disease and cancer combined.
EMS personnel should learn more about how to treat effects of trauma and decrease its incidence. (See “Injury Prevention and the Role of the EMS Provider” in Additional Student Resources on Resource Central.)
© Jack Degley Photography

2. Overview Steps of Scene Size-up Two basic mechanisms of motion injury
Three collisions associated with MVCs
Common forms of MVCs
Potential injuries associated with restraint systems
NOTE: Overview of presentation – continued on next slide.

3. Overview Assessment criteria and anticipated injuries from falls
Two most common forms of penetrating injury
Blast injury factors related to assessment
NOTE: Overview of presentation.

4. Trauma Care Teamwork is important! You must know:
What you can handle and what you can't
What you should handle and what you shouldn't
When to stay and when to leave
Fastest route there and fastest route away
What to do, what not to do, and when to wait
Often patient's life depends on how well you manage details, and not all of details are at scene.
You or a member of your team must:
Know how to maintain your ambulance or rescue vehicle so that it is serviced and ready to respond when needed.
Know quickest way to scene of an injury.
Know how to size up a scene in order to recognize dangers and identify mechanisms of injury.
Know which scenes are safe and, if not safe, what to do about them.
Know when you can handle a situation and when to call for help.
Know when to approach patient and when to leave with patient.
Know your equipment and maintain it in working order.
Know most appropriate hospital and fastest way to get there.
Know where to put your hands, which questions to ask, what interventions to perform, when to perform them, and how to perform critical procedures quickly and correctly.

5. Scene Size-up A critical part of trauma assessment
Anticipate what you will find at scene
Anticipate equipment and resource needs
Form a plan of approach
Be prepared to modify that plan
Failure to size-up can jeopardize lives

6. Scene Size-up First step in ITLS Primary Survey
NOTE: This is presented as an overview for a frame of reference for Scene Size-up. Assessment will be taught in detail in another section.
Emphasize that 1st step in assessment is always Scene Size-up.
Performing a good Scene Size-up will facilitate a good assessment; a poor Scene Size-up will complicate ensuing assessment and management.

7. Scene Size-up Standard precautions Scene safety
Initial triage (total number of patients)
Need for more help or equipment
Mechanism of injury
Scene Size-up includes taking standard precautions to prevent exposure to blood and other potentially infective material, evaluating scene for dangers, determining total number of patients, determining essential equipment needed for this particular scene, and identifying mechanisms of injuries.
Scene Size-up actually begins at dispatch, with anticipation of what will be found at scene.
At that time, think about what equipment will be needed and whether other resources may be needed.
Information from dispatch is useful in enabling you to begin to think about a plan, but this information is often exaggerated by caller or even completely wrong. Be prepared to change your plan depending on Scene Size-up.

8. Standard Precautions
Exposure to blood or OPIM very likely at a trauma scene
Appropriate PPE must be worn
Covered in more detail in Chapter 22
NOTE: Covered in more detail in Chapter 22.
Trauma scenes are among most likely to subject rescuer to contamination by blood or other potentially infectious material (OPIM).
Gloves, eye protection or face shields, impervious gowns as needed.
Remember to protect your patient from body fluids by changing gloves between patients.

9. Scene Safety Ambulance positioning Windshield survey
Safe place to park
Facing away from scene
Windshield survey
Threats to you
Threats to/from patient
Threats to/from bystanders
Position response vehicle away from hazards, but close enough to retrieve equipment efficiently and in a direction to leave scene easily.
Consider using vehicle as barrier to hazards (like oncoming traffic).
Windshield survey: Look out windshield for hazards before leaving your response vehicle.
Look for hazards as you approach.
Courtesy of Bonnie Meneely, EMT-P

10. Initial Triage Total number of patients Call for backup
Medical command
Initiate MCI protocols
Any more patients?
IMAGE: Where are patients at this scene? Where should you look? Where else should you look? It is possible a patient could have been located off-screen to top-left of image.
Courtesy of Bonnie Meneely, EMT-P

11. Need for More Essential equipment Additional resources
Carry to scene for time efficiency
Change gloves between patients
Additional resources
Call early
Relay where to respond and any dangers
The following equipment is always needed for trauma patients:
Personal protection equipment
Long backboard with effective strapping and head motion-restriction device
Appropriately sized rigid cervical extrication collar
Oxygen and airway equipment (suction equipment, BVM should be included)
Trauma box (bandage material, blood pressure cuff, stethoscope)

12. Mechanism of Injury Energy follows physics laws.
Injuries present in predictable patterns
High-energy at risk of severe injury.
Consider injured until proven otherwise
Type of MOI
Generalized
Focused
Missed or overlooked injuries may be catastrophic.
5–15% of patients involved in a high-energy event, despite normal vital signs and no apparent anatomic injury on initial assessment, will exhibit severe injuries on later examination.
A strong correlation exists between injury severity and automobile velocity changes, as measured by amount of vehicle damage. Severity of vehicle damage has also been suggested as a nonphysiologic triage tool.
Generalized mechanisms may require a rapid trauma survey whereas focused mechanisms may only require a focused exam.

13. Basic Motion Mechanisms
Blunt injuries
Rapid forward deceleration
Rapid vertical deceleration
Blunt instrument energy transfer
Penetrating injuries
Projectiles
Knives
Falls upon objects
Motion (mechanical) injuries are by and large responsible for the majority of mortality from trauma in United States and the industrial world .
Generally, blunt trauma is more common in rural settings, and penetrating trauma is more common in urban setting.
Rapid forward deceleration is usually blunt, but may be penetrating.
Most common example of rapid forward deceleration is motor-vehicle collision (MVC).

14. Motor-Vehicle Collisions
Each collision is three collisions:
Machine Collision 1
Body Collision 2
Organ Collision 3
Note: Slide animation
Consider all MVCs to occur as three separate events (Figure 1-2).
Machine collision
Body collision
Organ collision
To explain forces involved, consider Sir Isaac Newton's first law of motion: “A body in motion remains in motion in a straight line unless acted upon by an outside force.”
Motion is created by force (energy exchange), and, therefore, force will stop motion.
If this energy exchange occurs within body, damage of tissues is produced.

15. Other Collisions Secondary collisions Objects are missiles
Additional impacts
Vehicle collides with another object
Other vehicles collide with original vehicle
ANIMATION: ON CLICK package flies in from left of screen and hits patient's head.
Additional impacts may make it more difficult to predict injuries in these cases.
Quickly but carefully look for clues inside vehicle.

16. Clues to Injury Deformity of vehicle Deformity of interior structures
What forces were involved in collision?
Deformity of interior structures
What did patient hit?
Deformity or injury patterns on patient
What anatomic areas were hit?

17. Common Collisions Common types Frontal-impact Lateral-impact
Rear-impact
Rollover
Rotational
NOTE: Overview of next slides.
(© Jack Dagley Photography)

18. Frontal-Impact Collision
Windshield injuries
Brain, soft-tissue injury, cervical spine
Steering wheel injuries
Traumatic tattooing of skin
Dashboard injuries
Face, brain, cervical spine, pelvis, hip, knee
In head-on collision, the body is brought to a sudden halt, and energy transfer is capable of producing multiple injuries.
Windshield injuries: of utmost concern is potential for serious airway and cervical-spine injury.
Steering wheel deformity is a cause for alarm and must heighten your index of suspicion. You must also relay this information to receiving physician.
Potential injury patterns:
Deformed steering wheel
Cervical-spine fracture
Dashboard knee imprints
Flail chest
Spider deformity of windscreen
Myocardial contusion
Pneumothorax
Aortic disruption
Spleen or liver laceration
Posterior hip dislocation
Knee dislocation
(Courtesy of Maria Dryfhout, Shutterstock )

19. Lateral-Impact Collision
Similar to frontal-impact with lateral energy
Not easily predicted
Consider organ damage
Check impact side
Head, neck, upper arm, shoulder, thorax, abdomen, pelvis, legs
Potential injury patterns:
Contralateral neck sprain
Cervical-spine fracture
Lateral flail chest
Pneumothorax
Aortic disruption
Diaphragmatic rupture
Laceration of spleen, liver, kidney
Pelvic fracture
(Photo courtesy of Anthony Cellitti, NREMT-P)

20. Rear-Impact Collision
Posterior displacement
Rapid forward deceleration also possible
Headrest position
Hyperextension injuries
Damage back and front
Deceleration injuries
Sudden forward increase in acceleration from rear-impact mechanisms produces posterior displacement of occupants and possible hyperextension of cervical spine if headrest is not properly adjusted.
If seat back breaks and falls backward into rear seat, there is greater chance of lumbar-spine injury.
Rapid forward deceleration may also occur if car suddenly strikes something in front or if driver applies brakes suddenly.
Note deformity of auto anterior and posterior as well as interior deformity and headrest position.
Potential injury patterns:
Cervical-spine injury
(Courtesy of Bonnie Meneely, EMT-P)

21. Rollover Collision Multiple impacts Axial-loading injuries Ejection
Multiple directions
Multiple injuries
Axial-loading injuries
Spine injury
Ejection
Chance of death increases 25 times
The chance for axial-loading injuries of spine is increased in this form of MVC.
Courtesy of Bonnie Meneely, EMT-P
(Courtesy of Bonnie Meneely, EMT-P)

22. Rotational Collision Head-on, lateral-impact combination
Converts forward motion to spinning motion
Windshield, dashboard, steering wheel, side
Same possible injuries of both mechanisms
Rotational collision: One part of the vehicle stops and the rest of the vehicle remains in motion, converting forward motion to a spinning motion.
The results are a combination of frontal-impact and lateral-impact mechanisms with the same possibilities of injuries from both mechanisms.
© Dedyukhin Dmitry / Shutterstock.com

23. Occupant Restraint Lap belt Three-point restraint Air bags
Clasp knife effect
Abdomen
Lumbar spine
Three-point restraint
Cervical spine
Clavicular fracture
Air bags
First impact only
Always “lift and look”
Lumbar spine
Restrained occupants are more likely to survive a collision, because they are protected from much of impact inside the vehicle and are unlikely to be ejected.
If seatbelt is in place and victim is subjected to a frontal deceleration crash, his body tends to fold together like a clasp (or pocket) knife.
Air bags aka passive restraints:
Do not prevent “down and under” movement, so may still impact with legs and suffer leg, pelvis, or abdominal injuries.
Small drivers who bring seat up close to steering wheel may sustain serious injuries as airbag inflates.
Infants in car seats placed in the front seat may be seriously injured by air bag.
Supplemental restraint systems are only effective if occupant is NOT out of position (OOP).
(Courtesy of Olivier Le Queinec, Shutterstock.com)

24. Tractor Accidents 50% of farm fatalities Common injuries
Side overturns 85%
Likely to throw clear
Rear overturns 15%
Likely to entrap or crush
Common injuries
Crush injuries
Thermal or chemical burns
Two basic types of tractors are two-wheel drive and four-wheel drive. In both, center of gravity is high, and thus tractors are easily turned over.
The majority of fatal accidents are due to tractor turning over and crushing driver.
Primary mechanism is crush injury, and severity depends on part of anatomy involved.
Additional mechanisms are chemical burns from gasoline, diesel fuel, hydraulic fluid, or even battery acid.
Thermal burns from hot engine parts or ignited fuel are also common.
Courtesy of Roy Alson, MD

25. Small-Vehicle Crashes
Small vehicles
Motorcycles
All-terrain vehicles
Personal watercraft
Snowmobiles
Factors
Protective gear
Additional impacts
Operators of these machines are not encased within them and wear no restraining devices.
They could be considered high-speed pedestrians.
Only forms of protection:
Evasive maneuvering
Helmet usage
Protective clothing (such as leather clothes, helmet, boots)
Use of vehicle to absorb kinetic energy (such as bike slide)
NOTE: If any of these small vehicles are common in your area, include additional information from chapter.
© Orientaly / Shutterstock.com

26. Pedestrian Injuries Mechanism Common injuries Primary collision
Additional impacts
Common injuries
Internal injuries and fractures
Adult: bilateral leg, knee
Children: pelvis, torso
IMAGE: “Exploded” leg from being struck by an auto.
Pedestrian almost always suffers severe internal injuries as well as fractures.
This is true even if vehicle is traveling at low speed.
Adult usually has bilateral lower-leg or knee fractures plus whatever secondary injuries occur when body strikes hood of car and then ground.
Children are shorter, so bumper is more likely to hit them in pelvis or torso.
They usually land on their heads in secondary impact.
Courtesy of Bonnie Meneely, EMT-P

27. Falls Vertical deceleration Distance of fall Anatomy impact
Surface struck
IMAGE: How high up was patient when he fell?
Primary groups involved in vertical falls are adults and children under age of 5 years.
Children
Most commonly involve boys and occur mostly in summer months in urban high-rise, multiple-occupant dwellings.
Head injuries are common.
Adults
Generally occupational or due to influence of alcohol or drugs.
“Lover's leap” fall.
Attempt to land on feet, impacts initially on feet and then falls backwards, landing on buttocks and outstretched hands.
Fractures of feet or legs
Hip and/or pelvic injuries
Axial loading to lumbar and cervical spine
Vertical deceleration forces to organs
Colles fracture of wrists
Greater height, greater potential for injury.
Think about transference of energy from impact – what path did it follow
Surface density and irregularity also influence severity.
© Pearson

28. Penetrating Injuries Knife-wound severity Stabilize impaled object
Anatomic area penetrated
Fourth intercostal space may be chest and abdomen
Length of blade
Angle of penetration
Stabilize impaled object
Minimize external movement
IMAGE: Figure 1-16 Stab wounds at nipple level or below frequently penetrate abdomen.
Upper abdominal stab wound may cause intrathoracic organ injury, and stab wounds below fourth intercostal space may have penetrated abdomen.
Usually stabilize any impaled object in place.
Ensure that stabilization minimizes movement of object that will cause further damage
Impaled objects in cheek of face and those blocking airway are exceptions to this rule.

29. Penetrating Injuries Firearms Type of weapon Caliber Distance traveled
Low-velocity
High-velocity
Caliber
Missile size
Bullet construction
Tumbling/yaw
Distance traveled
IMAGE: High-velocity leg wound. Notice entrance and exit wounds.
Remember that you treat patient and wound, not description of weapon.
Low-velocity:
Less than 2,000 feet per second, include essentially all handguns and some rifles.
Injuries are much less destructive than those sustained from high-velocity weapons.
High-velocity:
Wounds carry additional factor of hydrostatic pressure.
Factors that contribute to tissue damage include:
Missile size. The larger the bullet, more resistance and larger permanent tract.
Bullet construction
Missile deformity. Hollow point and soft nose flatten out on impact, resulting in involvement of a larger surface.
Semijacket. The jacket expands and adds to surface area.
Tumbling. Tumbling of missile causes a wider path of destruction.
Yaw. The missile can oscillate vertically and horizontally (wobble) about its axis, resulting in a larger surface area presenting to tissue.
Courtesy of Roy Alson, MD

30. Penetrating Wounds Entry wound Exit wound Smaller
May be darkened, burned
Exit wound
One, none, or many
Larger
May be ragged
Penetrating wounds consist of 3 parts: entry wound, exit wound, and internal wound.
(©Edward T. Dickinson, MD)

31. Wound Ballistics Factors Missile velocity Missile size
Missile deformity
Missile design
Tumbling and yaw
IMAGE: Figure 1-17b.
High velocity is greater than 2,000 feet (610 meters) per second; less than that is low velocity (e.g., handguns, some rifles).
Missile deformity: projectile flattens out on impact increasing its surface area and causing more damage.
Missile design: semi-jacketed, soft nose, etc., expand differently.
Tumbling causes a wider path of destruction.
Yaw is the missile wobbling, resulting in a larger area presenting to the tissue.
(Courtesy of Roy Alson, MD)

32. Wound Ballistics Internal wound Damage proportional to tissue density
Tissue contact damage
High-velocity transfer of energy
Shock waves
Temporary cavity
Pulsation of temporary cavity
Damage proportional to tissue density
Highly dense tissue sustains more damage
IMAGE: Figure 1-17a High-velocity vs. low-velocity injury.
Penetrating wounds consist of 3 parts: entry wound, exit wound, and internal wound.
Low-velocity projectiles inflict damage by tissue contact.
High-velocity projectiles inflict damage by tissue contact and transfer of kinetic energy to surrounding tissues.
Shock waves
Temporary cavity, which is 30 to 40 times bullet's diameter and creates immense tissue pressures
Pulsation of temporary cavity, which creates pressure changes in adjacent tissue
Shotgun wounds, injury determined by kinetic energy at impact, which is influenced by:
Powder charge
Size of pellets
Choke of muzzle
Distance to target

33. Blast Injuries Primary Secondary Tertiary Quaternary Initial air blast
Material propelled
Tertiary
Impact on object
Quaternary
Dispersed hazardous material
IMAGE: Facial injuries shown here are tertiary from patient being thrown against a wall. Note that patient shown here has “raccoon eyes.”
NOTE: Figure 1-19 depicts blast areas.
Primary air-blast injuries are almost exclusive to air-containing organs.
Secondary injuries may be penetrating or blunt.
Tertiary injuries are much same as when a person is ejected from an automobile.
Now that terrorists are using explosives to disperse chemical, biological, or radiological material, some classify injuries resulting from this as “quaternary injuries.”

34. Scene Size-up is complete!
Caution
Do not approach until
Scene Size-up is complete!

35. Summary Time is critical; teamwork is essential
Scene size-up can be lifesaving
Mechanism of injury:
An aid to predict injury
Part of overall management of trauma patient
Record scene and mechanism findings
Stress need to do an accurate patient assessment.
MOI is a tool but not an absolute. We do not know all forces body may have been exposed to.