Sections • Introduction to Blunt Trauma • Kinetics of Blunt Trauma • Types of Trauma • Blunt Trauma • Explosion • Other Blunt Trauma • Examination, Diagnosis
Introduction toBlunt Trauma • Most common cause of trauma death and disability • Energy exchange between an object and the human body, without intrusion through the skin
Kinematics • Process of examining the scene to determine potential injuries that result from the forces of motion • Windshield, steering wheel, dashboard • Was the patient flying thru the air? • Roll-over? • Engine block on lap? (intrusion)
MOI • Mechanism of injury • description of the mechanical and physiological changes that result in anatomical or functional damage of tissue • Translation: What hit the patient???, what did the patient hit???!
Index of Suspicion • Based on the MOI and kinetics • Predict expected injuries • Experience counts here! • Be obsessive and compulsive, its OK!!
Kinetics of Blunt Trauma • Inertia • “A body in motion will remain in motion unless acted upon by an outside force.” • “A body at rest will remain at rest unless acted upon by an outside force.” (Newton) • Conservation of Energy • “Energy can neither be created nor destroyed. It is only changed from one form to another.” (Newton)
Kinetics of Blunt Trauma • Force (Newton’s 2nd law of motion) • Emphasizes the importance of rate at which an object changes speed (acceleration or deceleration)
SOOOO • The Force that puts an object in motion must be absorbed before the object will stop. • Guess what absorbs that force???? • This absorption is what causes tissueinjury in the body.
Kinetics of Blunt Trauma • Kinetic Energy • Energy in Motion • Double Weight = Double Energy • Double Speed = Quadruple Energy SPEED IS THE GREATESTDETERMINANT
Physics (UGH!) • Three types of forces in blunt trauma • Compression • Shear • Overpressure
Compression • Like laying an organ on a table and hitting it with a hammer, every time you hit it, cells are getting compressed and crushed. • Enough said…..
Shear • Occur when the organ and the organ’s attachment do not accelerate or decelerate at the same rate of speed, or two parts of an organ accelerate or decelerate at different rates. • Examples are arch of aorta, spleen, kidney.
Overpressure • Like hitting a closed paper bag with the open hand….the bagpops. • Examples are like steering column hitting abdomen…pop! goes the diaphragm. Also can pop bladder, bowel, lungs……
Types of Trauma • Blunt • Closed injury • Indirect injury to underlying structures • Transmission of energy into the body • Tearing of muscle, vessels and bone • Rupture of solid organs • Organ injury • Ligamentum teres in the chest for example
Blunt Trauma: Car Crashes • 44,000 people die each year on US highways • Events of Impact • Vehicle Collision • Body Collision • Organ Collision • Secondary Collisions • Objects inside vehicle strike occupant • Additional Injuries • Vehicle receives a second impact
Protections (think Volvo!) • Steel frame • Belts • Bags • Seat construction • Roof • Crumple Zones
Blunt Trauma: Car Crashes • Restraints • Seatbelts • Occupant slows with the vehicle • Shoulder and Lap belts MUST be worn together • Injuries if worn separately • Airbags (SRS) • Reduce blunt chest trauma • Cause: Hand, Forearm, & Facial Injury • Check for steering wheel deformity • Side Airbags • Child Safety Seats • Infants and Small Children: Rear facing • Older Child: Forward facing
Benefits of Air bags • 700-1000 lives saved if all vehicles had head protecting SABs per year • In side impacts where someone died, 60% suffered brain injury. • Only 92 cases of SAB injury, 6 involving children, with no major injuries, only one minor injury (skin lac).
Bags and Belts • Burns, abrasions • Do not protect when a second collision hits! • Abdominal injuries (seat too close) • Chest injuries (short, elderly) • Seat belt abrasions above the pelvis account for a 30-60% incidence of intra-abdominal injuries: intestinal rupture, mesenteric injury, vascular disruption
Blunt Trauma: Automobile Crashes • Types of Impact • Frontal: 32% • Lateral: 15% • Rotational: 38% • Left & Right – Front & Rear • Rear-end: 9% • Rollover: 6%
Blunt Trauma: Car Crashes • Frontal Impact • Down-and-Under (legs lead point) • Knee, femur, and hip fracture (dislocation of knee, fx acetabulum) • Chest trauma-Steering Wheel • Up-and-Over (head lead point) • Head, c-spine injuries • Tenses legs = Bilateral femur fracture • Hollow organ rupture and liver laceration • Similar chest trauma • Axial Loading • Ejection • Due to up-and-over pathway • Contact with the vehicle & external object
Blunt Trauma: Automobile Crashes • Lateral Impact (intersection race) • 15% of MVC’s but 22% of deaths • Upper extremity injury • Rib, clavicle, humerus, pelvis, femur fracture, c-spine dislocations, locked facets. • Lateral compression • Ruptured diaphragm, Spleen fracture, Aortic injury EVALUATE the unrestrained occupant
Blunt Trauma:Car Crashes • Rotational • Vehicle struck at oblique angle • Less serious injuries unless strike a secondary object
Blunt Trauma:Car Crashes • Rear-end • Seat propels the occupant forward • Head is forced backwards • Stretching of neck muscles and ligaments • Hyperextension & hyperflexion (think carotid) • Rollover • Multiple points of impact • Ejection or partial ejection (think: arm out of window, then roll….) • Less injury with restraints
Blunt Trauma: Automobile Crashes • Vehicle Crash Analysis • Crumple Zones • Intrusion (one inch for each mile per hour) • Deformity of Vehicle • Use of Restraints • Intoxication • Fatal Accidents: >50% involved ETOH • Recreational Accidents
Blunt Trauma: Automobile Crashes • Vehicular Mortality • Head: 48% • Internal (Torso): 37% • Spinal & Chest fracture: 8% • Extremity fracture: 2% • All Other: 5%
Blunt Trauma: Automobile CrashesCrash Evaluation • Collision Questions • How did collision occur? • Direction? • Speed? • Similar/Different sized? • Secondary collisions? • Cause of Crash • Weather & visibility? • Alcohol involved? • Skid marks? • Auto Interior • Starring of windshield? • Steering wheel deformity? • Dash deformity? • Intrusion?
The “Lucky Other Guy” • The passenger in the same car as the deceased driver for example. • BUT, this “lucky”person was in the same vehicle and the energy exchange on the body was the same. • So you’d better find that unrecognized injury!
Blunt Trauma: Motorcycle Crashes • Serious injuries can occur with high and low speed collision. • Types of Impact • Frontal • Angular • Sliding (“laying the bike down”) • Ejection • Initial Bike/Object Collision • Rider/Object • Rider/Ground
Motorcycle Injuries • No helmet use increases chance of head injury by 300%. • Does not protect c-spine, but does not injure it either. • Anti-helmet organizations such as American Motorcycle Association may say different………
Blunt Trauma:Pedestrian Struck • Adults • Adults turn away and run (lat,post injuries) • Bumper strikes lower legs first • Victim rolls up and over and thrown • Children • Children turn toward (ant injuries) • Femurs, Pelvis often injured • Thrown away or run over
Blunt Trauma: Recreational Vehicle Accidents • Lack structure and restraint system • Types of Vehicles • Snowmobiles • Personal watercraft • ATV’s
Other Types of Blunt Trauma • Falls • Stairs, Force, Surface • Landing Area • Surface Type • Body Part • Height of Fall (3 times height of victim) • Elderly • Axial Loading…..