Kinematics of Trauma Flashcards
What is kinematics?
- It describes the motion of objects without consideration of how that motion occurred.
How does kinematics describe motion?
- Type of motion
- Location of motion
- Magnitude of motion
- Direction of motion
What does understand the kinematics of a car crash or fall allow us as paramedics to understand or grasp an understanding or idea of?
- Enables prediction of injury patterns.
What is Velocity?
- The rate of change of positions. You require the speed and direction of the object to figure out your Velocity.
What are the 4 Physical laws that are relevant in trauma?
- Newton’s First Law
o An object, either at rest or in motion, will remain in that state until acted upon. - Conservation of Energy
o Energy cannot be created or destroyed, only the state can be changed - Newton’s Second Law of Motion
o Net Force (F) = mass (M) x acceleration (a) - Kinetic Energy
o KE = half the mass (1/2 M) x velocity Squared (v2)
What do these laws of physics mean to a paramedic?
- A paramedic should be aware of them for trauma jobs as you consider the forces involved, what a larger car traveling at higher speed does to a patient, compared to a smaller or lighter car traveling at lower speeds.
What three types of impacts occur doing an MVA were energy is transferred?
- Vehicle collides with object
- Occupant collides with the inside of the vehicle
- Organs collide with the inside of the occupants
What forces are associated with the above triad?
- Blunt and shearing forces applied to the body during rapid deceleration.
What factors alter the type of injury a patient may suffer in an MVA.
- The type of collision
- The position of the occupant and types of objects that they are likely to strike
- The application of vehicle fitted restraints or the deployment of air bags
What are the 5 groups of mechanism in an MVA?
- Head on (frontal) Impact
- Later impact
- Rear end impact
- Rotational impact
- Rollover
In what direction can an unrestrained passenger travel in car in relation to the dashboard?
- Down and under it (knees are the leading part of the body)
- Up and over (Ribs and thorax are leading part of the body)
What are potential injuries from down and under type forces?
- Femoral and hip fractures and associated haemorrhages
- Knee and lower leg fractures and associated haemorrhage
What are potential injuries from up and over type forces?
- Rib fracture and hemopneumothorax
- Pulmonary or cardiac contusion
- Abdominal organ and major vessel rupture and laceration
- Traumatic head and spinal injuries
When does lateral impact occur?
- When a vehicle is hit on its side, also referred to as a T-bone.
What are some considerations when attending a lateral impact?
- Has the vehicle remained in place after initial impact?
- How many passengers are in the car?
- How much intrusion has occurred into the cabin?
- Has ejection occurred? Either through empty baby seats or other passengers?
What are possible patterns of injury included in a later impact?
- Compression of pelvis, abdomen and torso
- Rib fracture and pulmonary contusion
- Organ rupture. In particular spleen/liver
- Pelvic fracture
- Head and neck injuries
Does a standard seatbelt provide restraint in the case of a lateral impact?
- No
What occurs when a vehicle is struck from behind?
- Rapid acceleration occurs
What are possible injuries of a rear impact?
- Spinal injuries especially hypertension of the C- Spine.
What type of injuries occur in a rotational Impact?
- Occupants suffer injuries that are common in frontal and lateral impacts.
What injuries may be sustained in a roll over impact?
- Occupants are thrown around within the vehicle.
- People may sustain multiple system injures associated with all mechanism of MVA.
What else may occur during a roll over incident?
- Other objects within the car may turn in to projectiles and occupants may also be ejected allowing further injuries to be sustained.
What are common types of Deceleration and compression injuries?
- Head injuries
- Thoracic injuries and abdominal
What are the forces involved in the deceleration injuries?
- Shearing forces that may leave the PT presenting perfectly unharmed but the forces have caused a significant organ to fail or become detached or rupture.
What is the likely hood of death for those patients ejected from vehicles?>
- 6 times the risk of death.
What types of impacts can a seatbelt provide protection from?
- Forward and rear. However, they are not always able to prevent injuries.
What do airbags do?
- They absorb energy slowly, they also deploy and deflate within 0.5 seconds.
In what types of crashes are frontal airbags of little to no use?
- Lateral and rollover collisions
What potential injuries are airbags likely to cause?
- Abrasions, foreign bodies to face/eyes or allergic/respiratory reactions and burns.
What is the cause of whiplash?
- The head extending backward from the torso in the initial stage of rear impact the being thrown forward.
