Force acting over distance (Man hits ground). Work is what causes injuries. Force=Mass X Acceleration.
Severity of injuries
Amount of kinetic energy converted to work dictates severity. Speed is most reliable indicator: 2x speed = 4x energy.
Vehicular collisions (3 collisions)
Every crash has three collisions. 1. Collision of car against another car or object 2. Collisions of passengers against interior of car 3. Collision of passenger's internal organs against solid structures of the body.
Mechanism of injury
MOI is the way that traumatic injuries occur. Different MOIs produce many types of injuries (isolated to one body system or systemic)
Blunt trauma definition
Caused by force to the body. Injuries do not penetrate soft tissue or organs.
Penetrating trauma definition
Caused by objects such as knives and bullets. Injuries pierce the surface of the body.
MVCs and MOI
Determine MOI by assessing crash to predict types of injuries at time of impact. What does passenger compartment look like?
Significant MOI in MVCs
1. Severe deformity to front of vehicle 2. Moderate intrusion from T-bone 3. Severe damage to rear 4. Collisions in which rotation is involved
Evaluate seat belts and airbags. Check for contact points (including under airbags).
Whiplash is common. Unrestrained passengers will be thrust forward into dashboard. Back seat passengers wearing only lap belts have higher incidence of lumbar and thoracic spine injury.
Responsible for highest incidence of deaths (25% of severe injuries to aorta are due to T-bone). Lateral whiplash is common cause of sudden death. Often results in intrusion into passenger compartment.
Injury patterns differ if patients are unrestrained (multiple contact points for unrestrained passengers!). Ejection is most common life-threatening injury.
Vehicle put into rotational motion. Vehicle often strikes a fixed object, combining forces of rotation with lateral impact.
Car Vs. Pedestrian
Often causes serious injury to body SYSTEMS. Evaluate MOI to find out: 1. Speed of vehicle 2. Whether patient was thrown and how far/or pulled under vehicle 3. Any damage to vehicle? 4. Apparent injuries to patient?
Injury potential related to height of fall. Fall 15' or 3X person's height is SIGNIFICANT. Suspect internal injuries from significant fall.
Considerations for falls
1. Height of fall 2. Surface struck 3. Part of body that hit first, followed by path of energy displacement 4. Consider underlying medical conditions as cause (syncope)
Penetrating trauma kinematics
Penetration can be low-energy (knife) or high-to-high velocity (bullet). The greater the speed of the penetration, the greater the injuries.
Low-energy penetrating trauma
Caused accidentally by object or intentionally w/ weapon. Injury caused by sharp edges of object moving through body.
Medium-velocity and high-velocity penetrating trauma
Usually caused by bullets. Bullets can change shape and ricochet through body. Speed creates pressure waves (cavitation). Find weapon caliber and shooting distance, if possible.
Injuries to the head
Bruising or tearing of brain. Bleeding or swelling inside skull is often life-threatening. Some patients may not have signs and symptoms
Injuries to neck
Tearing or swelling of trachea causes airway problems. Injury to large neck blood vessels may swell and prevent blood flow to brain. Open wounds to neck vein bleed heavily or allow air to enter circulatory system.
Injuries to chest
Broken ribs may interfere with chest's ability to expand normally. Large vessels may tear, causing massive bleeding.
Air collecting between lung tissue and chest wall ( blood = hemopneumothorax). Compression of lung tissue interferes with oxygen exchange. May also interfere with the functioning of the heart (tension pneumothorax).
Solid organs can tear, lacerate or fracture, causing serious bleeding and death. Hollow organs can leak digestive fluid.