Section 5: Trauma

Chapter 18 Mechanisms and Patterns of Injury

Chapter 18: Mechanisms and Patterns of Injury 3 Describe what is meant by “mechanism of injury” (MOI). Discuss the importance of kinetic energy in producing injuries. Describe the types of trauma and give examples of injuries produced by each type. Objectives (1 of 2)

Chapter 18: Mechanisms and Patterns of Injury 4 List some significant mechanisms of injury. Relate how the characteristics of the human body tissues and organs and the laws of physics apply to trauma injuries. Describe the process of using the mechanism of injury to predict injuries. Objectives (2 of 2)

Chapter 18: Mechanisms and Patterns of Injury 5 Mechanism of Injury A concept that uses the characteristics of the human body and the laws of physics to understand, predict, and anticipate injury and injury patterns

Chapter 18: Mechanisms and Patterns of Injury 6 Tissue Characteristics Determine ease of injury Influence manner and frequency of injury –Skin - lacerations –Bones - fractures Skeleton provides protection for organs. Injuries are associated with motion. Extremities are more likely to be injured, due to frequent motion.

Chapter 18: Mechanisms and Patterns of Injury 7 Mechanism Terms (1 of 3) Force –Any action that changes the rest or motion of a body Body –Any mass of matter distinct from other masses Energy –The capacity for doing work

Chapter 18: Mechanisms and Patterns of Injury 8 Mechanism Terms (2 of 3) Work –Force acting over distance Kinetic energy –Energy of moving object Potential energy –Product of weight, gravity, and height

Chapter 18: Mechanisms and Patterns of Injury 9 Mechanism Terms (3 of 3) Trauma –End effect of force applied to the human body Injury –Actual type and extent of damage to the body

Chapter 18: Mechanisms and Patterns of Injury 10 Newton’s First Law Objects at rest tend to stay at rest, and objects in motion tend to stay in motion, unless they are acted upon by some force.

Chapter 18: Mechanisms and Patterns of Injury 11 Law of Conservation of Energy (1 of 2) Energy can neither be created nor destroyed, but may be changed from one form to another. When an object strikes the body, the energy of motion is dispersed and dissipated by body tissue; this can cause injury. Velocity or speed is a critical factor when considering kinetic energy.

Chapter 18: Mechanisms and Patterns of Injury 12 Law of Conservation of Energy (2 of 2) Kinetic energy from falling is important to consider. A body will accelerate to the terminal velocity when falling (approx 200’/sec). Kinetic energy has both strength and direction to cause the body to accelerate or decelerate.

Chapter 18: Mechanisms and Patterns of Injury 13 Types of Trauma (1 of 2) Penetrating Blunt (compression) Bending (hyperflexion, hyperextension) Rotational Distraction (stretching)

Chapter 18: Mechanisms and Patterns of Injury 14 Types of Trauma (2 of 2) Trauma can be a combination of types. Determined by magnitude and direction of forces Techniques and equipment can modify, control, and dissipate forces, ie, helmets rolling with the fall.

Chapter 18: Mechanisms and Patterns of Injury 15 Types of Injuries (1 of 4) Puncture wounds are caused by objects that focus force and penetrate skin. Contusions and hematomas are caused by blunt force: –Do not break skin –Injure skin and tissue underneath –Can injure both organs and bones

Chapter 18: Mechanisms and Patterns of Injury 16 Types of Injuries (2 of 4) Fractures, dislocations, and sprains occur when joints are bent or rotated beyond normal range. Crushing injuries can occur when blunt forces act on the body, either: –Gradual –Momentary

Chapter 18: Mechanisms and Patterns of Injury 17 Types of Injuries (3 of 4) Dislocations, lacerations, and fractures occur when forces distract or stretch tissue. Internal bleeding/organ contusions can occur with rapid acceleration/deceleration. –Tissue is subjected to blunt force from contact with other body structures.

Chapter 18: Mechanisms and Patterns of Injury 18 Types of Injuries (4 of 4) Amount of damage is proportional to amount of energy involved. Injuries may reflect multiple types of trauma (ie, bending and distraction). Be aware of fulcrum points that may focus and multiply forces.

Chapter 18: Mechanisms and Patterns of Injury 19 Patterns of Injury Concept that uses MOI to anticipate injuries that are not readily apparent Injuries tend to occur in patterns with predictable types: –Vehicle collisions –Falls –Outdoor sports –White water sports

Chapter 18: Mechanisms and Patterns of Injury 20 MOI Factors (1 of 2) Energy: speed, direction, and focus Surface: smooth/rough, hard/soft Body: which parts, body position Trauma: blunt, penetrating, bending…

Chapter 18: Mechanisms and Patterns of Injury 21 MOI Factors (2 of 2) External/internal injuries Signs and symptoms of specific injuries not apparent: shock, fractures… Spinal injuries

Chapter 18: Mechanisms and Patterns of Injury 22 Scene Size-Up (1 of 2) MOI is an essential part of assessment. Use your experience to understand and discover all injuries. Recognize that internal injuries can be difficult to detect.

Chapter 18: Mechanisms and Patterns of Injury 23 Scene Size-Up (2 of 2) Treat for internal injuries before they become obvious. Determine the magnitude of forces, areas of the body involved, and external protection to identify the significance of MOI.

Chapter 18: Mechanisms and Patterns of Injury 24 Significant MOIs (1 of 3) Fall: 2.5 to 3 times body height, less if in motion before fall Moderate to high speed vehicle collision: –Fatality has occurred –Patient was unrestrained –Ejected from vehicle –Vehicle rolled over –Major intrusion into vehicle (motorcycle, snowmobile) –Patient was not wearing a helmet

Chapter 18: Mechanisms and Patterns of Injury 25 Significant MOIs (2 of 3) Pedestrian struck by a vehicle moving faster than 25 mph. Collision with another skier or rider Collision with a fixed object while skiing or riding Gunshot wound to head, neck, chest abdomen, or pelvis Patient unresponsive due to head injury

Chapter 18: Mechanisms and Patterns of Injury 26 Significant MOIs (3 of 3) Shock or respiratory distress with no explanation Avalanche burial Explosion Struck by a falling object High voltage or high amperage electrical shock