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CMSgt John Jonckers, Superintendent 141st MDG
Medical SMEE - Thailand

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  • The physics of motion, the science of motion that is what kinematics is. It uses all the laws of physics from gravity, energy, water & air compression.
  • Kinematics

    1. 1. KINEMATICS An Introduction to the Physics of Trauma CMSgt John Jonckers, Superintendent 141 st MDG Medical SMEE - Thailand
    2. 2. Trauma Statistics <ul><li>100,000 trauma deaths/year </li></ul><ul><li>One-third are preventable </li></ul><ul><li>Unnecessary deaths often caused by injuries missed because of low index of suspicion </li></ul><ul><li>Raise index of suspicion by evaluating scene as well as patient </li></ul>
    3. 3. Kinematics <ul><li>Physics of Trauma </li></ul><ul><li>Prediction of injuries based on forces and motion involved in injury event </li></ul><ul><li>Mechanism of Injury </li></ul><ul><li>Index of suspension </li></ul>
    4. 4. Physical Principles <ul><li>Kinetic Energy </li></ul><ul><li>Newton’s First Law of Motion </li></ul><ul><li>Law of Conservation of Energy </li></ul>
    5. 5. Kinetic Energy <ul><li>Energy of motion </li></ul><ul><li>K.E. = 1/2 mass x velocity 2 </li></ul><ul><li>Major factor = Velocity </li></ul><ul><li>“ Speed Kills” </li></ul>
    6. 6. Newton’s First Law of Motion <ul><li>Body in motion stays in motion unless acted on by outside force </li></ul><ul><li>Body at rest stays at rest unless acted on by outside force </li></ul>
    7. 7. Law of Conservation of Energy <ul><li>Energy cannot be created or destroyed </li></ul><ul><li>Only changed from one form to another </li></ul>
    8. 8. Conclusions <ul><li>When moving body is acted on by an outside force and changes its motion, </li></ul><ul><li>Kinetic energy must change to some other form of energy. </li></ul><ul><li>If the moving body is a human and the energy transfer occurs too rapidly, </li></ul><ul><li>Trauma results. </li></ul>
    9. 9. Types of Trauma <ul><li>Penetrating </li></ul><ul><li>Blunt </li></ul><ul><ul><li>Deceleration </li></ul></ul><ul><ul><li>Compression </li></ul></ul>
    10. 10. Motor Vehicle Collisions <ul><li>Five major types </li></ul><ul><ul><li>Head-on </li></ul></ul><ul><ul><li>Rear-end </li></ul></ul><ul><ul><li>Lateral </li></ul></ul><ul><ul><li>Rotational </li></ul></ul><ul><ul><li>Roll-over </li></ul></ul>
    11. 11. Motor Vehicle Collisions <ul><li>In each collision, three impacts occur: </li></ul><ul><ul><li>Vehicle </li></ul></ul><ul><ul><li>Occupants </li></ul></ul><ul><ul><li>Occupant’s organs </li></ul></ul>
    12. 12. Head-on Collision <ul><li>Vehicle stops </li></ul><ul><li>Occupants continue forward </li></ul><ul><li>Two pathways </li></ul><ul><ul><li>Down and under </li></ul></ul><ul><ul><li>Up and over </li></ul></ul>
    13. 13. Rear-end Collision <ul><li>Car (and everything touching it) moves forward </li></ul><ul><li>Body moves, head does not, causing whiplash </li></ul><ul><li>Vehicle may strike other object causing frontal impact </li></ul><ul><li>Worst patients in vehicles with two impacts </li></ul>
    14. 14. Lateral Collision <ul><li>Car appears to move from under patient </li></ul><ul><li>Patient moves toward point of impact </li></ul>
    15. 15. Rotational Collision <ul><li>Off-center impact </li></ul><ul><li>Car rotates around impact point </li></ul><ul><li>Patients thrown toward impact point </li></ul><ul><li>Injuries combination of head-on, lateral </li></ul><ul><li>Point of greatest damage = Point of greatest deceleration = Worst patients </li></ul>
    16. 16. Roll-Over <ul><li>Multiple impacts each time vehicle rolls </li></ul><ul><li>Injuries unpredictable </li></ul><ul><li>Assume presence of severe injury </li></ul>
    17. 17. Restrained vs Unrestrained <ul><li>Ejection </li></ul><ul><ul><li>27% of motor vehicle collision deaths </li></ul></ul><ul><ul><li>1 in 13 suffers a spinal injury </li></ul></ul><ul><ul><li>Probability of death increases six-fold </li></ul></ul>
    18. 18. Pedestrians <ul><li>Child </li></ul><ul><ul><li>Faces oncoming vehicle </li></ul></ul><ul><ul><li>Waddell’s Triad </li></ul></ul><ul><ul><ul><li>Bumper Femur fracture </li></ul></ul></ul><ul><ul><ul><li>Hood Chest injuries </li></ul></ul></ul><ul><ul><ul><li>Ground Head injuries </li></ul></ul></ul>
    19. 19. Pedestrians <ul><li>Adult </li></ul><ul><ul><li>Turns from oncoming vehicle </li></ul></ul><ul><ul><li>O’Donohue’s Triad </li></ul></ul><ul><ul><ul><li>Bumper Tib-fib fracture Knee ligament tears </li></ul></ul></ul><ul><ul><ul><li>Hood Femur/pelvic fractures </li></ul></ul></ul>
    20. 20. Falls <ul><li>Critical Factors </li></ul><ul><ul><li>Height </li></ul></ul><ul><ul><ul><li>Increased height = Increased injury </li></ul></ul></ul><ul><ul><ul><li>Always note & report </li></ul></ul></ul><ul><ul><li>Surface </li></ul></ul><ul><ul><ul><li>Decreased stopping distance = Increased injury </li></ul></ul></ul><ul><ul><ul><li>Always note & report type of surface </li></ul></ul></ul>
    21. 21. Stab Wounds <ul><li>Damage confined to wound track </li></ul><ul><ul><li>Four-inch object can produce nine-inch track </li></ul></ul><ul><li>Gender of attacker </li></ul><ul><ul><li>Males stab up; Females stab down </li></ul></ul><ul><li>Evaluate for multiple wounds </li></ul><ul><ul><li>Check back, flanks, buttocks </li></ul></ul>
    22. 22. Stab Wounds <ul><li>Chest/abdomen overlap </li></ul><ul><ul><li>Chest below 4th ICS = Abdomen until proven otherwise </li></ul></ul><ul><ul><li>Abdomen above iliac crests = Chest until proven otherwise </li></ul></ul>
    23. 23. Gunshot Wounds <ul><li>Damage to be determined by location of entrance/exit wounds </li></ul><ul><ul><li>Missiles tumble </li></ul></ul><ul><ul><li>Secondary missiles from bone impacts </li></ul></ul><ul><ul><li>Remote damage from </li></ul></ul><ul><ul><ul><li>Blast effect </li></ul></ul></ul><ul><ul><ul><li>Cavitation </li></ul></ul></ul>
    24. 24. Gunshot Wounds Severity cannot be evaluated in the field or Emergency Department Severity can only be evaluated in Operating Room
    25. 25. Blast Mechanics <ul><li>Three types of explosions </li></ul><ul><ul><li>Mechanical </li></ul></ul><ul><ul><ul><li>Compressed gas cylinders </li></ul></ul></ul><ul><ul><li>Nuclear </li></ul></ul><ul><ul><ul><li>Sustained atomic reaction </li></ul></ul></ul><ul><ul><li>Chemical </li></ul></ul><ul><ul><ul><li>Small amount of solid or liquid material converted into a very large amount of gas in a very short time. </li></ul></ul></ul>
    26. 26. Blast Mechanics <ul><li>Explosive Blasts are essential to our society: </li></ul><ul><ul><li>Automobile engines </li></ul></ul><ul><ul><li>Mining & earth moving </li></ul></ul><ul><ul><li>Bonding dissimilar metals </li></ul></ul><ul><ul><ul><li>Sandwiched copper in Quarters </li></ul></ul></ul><ul><ul><li>Aircraft construction </li></ul></ul><ul><ul><ul><li>Explosive rivets </li></ul></ul></ul><ul><ul><li>Throwing life lines between boats </li></ul></ul><ul><ul><li>Preventing avalanches </li></ul></ul>
    27. 27. Blast Mechanics <ul><li>Blast Overpressure </li></ul><ul><li>Blast winds </li></ul><ul><li>Burns </li></ul>
    28. 28. Blast Mechanics Blast Overpressure <ul><li>Expanding gases force out in all directions </li></ul><ul><ul><li>Subsonic or supersonic speeds </li></ul></ul><ul><ul><ul><li>not important to medical providers </li></ul></ul></ul><ul><ul><li>Objects can be thrown at 2000 mph </li></ul></ul>
    29. 29. Blast Mechanics Blast Overpressure <ul><li>Only chemicals are destroyed / incinerated </li></ul><ul><ul><li>Bomb pieces are bent/twisted but remain intact </li></ul></ul><ul><ul><li>Important for evidence </li></ul></ul><ul><li>Instantaneous increase in “Atmospheric Pressure” </li></ul><ul><ul><li>Followed by instantaneous ‘vacuum’ </li></ul></ul><ul><ul><li>Immediate return to normal pressure </li></ul></ul>
    30. 30. Blast Mechanics Blast Winds <ul><li>Ever expanding air mass makes its own wind </li></ul><ul><ul><li>1500 mph after a 100 psi overpressure </li></ul></ul><ul><ul><li>Objects are blown into people </li></ul></ul><ul><ul><li>People are thrown against objects </li></ul></ul>
    31. 31. Blast Mechanics Thermal Burns <ul><li>Burns? </li></ul><ul><li>High temps in expanding gas cloud </li></ul><ul><ul><li>Lasts only a very short time </li></ul></ul><ul><li>Burn injuries are rare </li></ul><ul><ul><li>More common among the dead </li></ul></ul><ul><ul><li>Few victims admitted to burn centers </li></ul></ul><ul><li>UNLESS A SUBSEQUENT FIRE ! </li></ul>
    32. 32. Blast Mechanics Mechanisms of Injury <ul><li>Blast casualties are affected by </li></ul><ul><ul><li>Open air or closed room </li></ul></ul><ul><ul><ul><li>Distance from the blast </li></ul></ul></ul><ul><ul><ul><li>Size of room </li></ul></ul></ul><ul><ul><ul><li>Height of ceiling </li></ul></ul></ul><ul><ul><li>Was there a building collapse? </li></ul></ul><ul><ul><li>Number of persons in the area </li></ul></ul><ul><ul><li>Was shrapnel used? </li></ul></ul><ul><ul><li>Was there a resultant fire? </li></ul></ul>
    33. 33. Blast Pathophysiology <ul><li>Blast overpressure </li></ul><ul><li>Air filled organs most vulnerable </li></ul><ul><ul><li>Lungs (injury threshold – 4.2 psi) </li></ul></ul><ul><ul><li>Alveoli can compress – fluid filled capillaries can not </li></ul></ul><ul><ul><li>Torn capillary membranes </li></ul></ul><ul><ul><ul><li>Pulmonary contusion </li></ul></ul></ul><ul><ul><ul><li>‘Blast Lung’ </li></ul></ul></ul><ul><ul><li>Pneumo-thorax if air escapes into pleura </li></ul></ul>
    34. 34. Blast Pathophysiology <ul><li>Blast Lung: </li></ul><ul><ul><li>Hypoxemia </li></ul></ul><ul><ul><ul><li>possible hypotension, bradycardia, hemoptysis </li></ul></ul></ul><ul><ul><li>May take 12-24 hours to develop </li></ul></ul><ul><li>Treat similarly to other hypoxic situations </li></ul><ul><ul><li>High flow O 2 by mask </li></ul></ul><ul><ul><li>Consider intubation if severe </li></ul></ul><ul><ul><li>No diuretics </li></ul></ul><ul><ul><li>Good long term outcomes without sequela </li></ul></ul>
    35. 35. Blast Pathophysiology <ul><li>Blast overpressure </li></ul><ul><li>Air filled organs are most vulnerable to injury </li></ul><ul><ul><li>Abdomen & GI tract (injury threshold 6 psi) </li></ul></ul><ul><li>Air is compressed & balloons out in other areas </li></ul><ul><ul><li>Ruptured intestinal wall </li></ul></ul><ul><ul><ul><li>Ileo-cecal joint most common to burst </li></ul></ul></ul><ul><ul><li>More common in underwater blasts </li></ul></ul><ul><ul><ul><li>Possibility must be considered in all situations </li></ul></ul></ul>
    36. 36. Blast Pathophysiology <ul><li>Blast overpressure </li></ul><ul><ul><li>Abdomen & GI tract: </li></ul></ul><ul><li>As tissue layers are compressed & released; </li></ul><ul><ul><li>Disrupts epithelial, mucosal, sub-mucosal tissues </li></ul></ul><ul><ul><ul><li>Resultant hemorrhage, necrosis, possible emboli </li></ul></ul></ul><ul><ul><li>Symptoms similar to abdominal trauma </li></ul></ul><ul><ul><li>Challenge in predicting future of lesion </li></ul></ul><ul><ul><ul><li>Burst or spontaneous recovery? </li></ul></ul></ul>
    37. 37. Blast Pathophysiology <ul><li>Blast overpressure </li></ul><ul><li>Auditory (injury threshold 5 psi) </li></ul><ul><ul><li>Pressures cant equalize quickly enough </li></ul></ul><ul><ul><ul><li>Ruptured tympanic membranes </li></ul></ul></ul><ul><ul><ul><ul><li>most heal spontaneously </li></ul></ul></ul></ul><ul><ul><ul><li>Dislocated/fractured ossicles </li></ul></ul></ul><ul><ul><li>Multiple long term problems </li></ul></ul><ul><ul><ul><li>Tinititis, vestibular, sensory loss </li></ul></ul></ul><ul><li>Not reliable indicator of concealed injuries! </li></ul><ul><ul><li>Detailed additional exams recommended </li></ul></ul>
    38. 38. Blast Pathophysiology <ul><li>Blast overpressure </li></ul><ul><li>Neurological </li></ul><ul><ul><li>Air emboli may happen </li></ul></ul><ul><ul><ul><li>Blast bends? </li></ul></ul></ul><ul><ul><ul><li>Air admitted through damaged lung capillaries? </li></ul></ul></ul><ul><ul><li>May be a cause of death </li></ul></ul><ul><ul><li>Not significant pathology in survivors </li></ul></ul><ul><li>Transient flattening of EEG waves in pigs </li></ul>
    39. 39. Blast Pathophysiology <ul><li>Blast forces and blast winds </li></ul><ul><ul><li>Direct tissue trauma </li></ul></ul><ul><ul><ul><li>Flying objects hitting victims (Shrapnel) </li></ul></ul></ul><ul><ul><ul><li>Victims hitting other objects (Tertiary contacts) </li></ul></ul></ul><ul><ul><li>Amputation </li></ul></ul>
    40. 40. Blast Pathophysiology <ul><li>Intentional Shrapnel </li></ul><ul><li>Ball bearings, nuts, bolts, nails etc. </li></ul><ul><ul><li>Penetrating injuries similar to multiple small arms fire </li></ul></ul><ul><ul><li>Hundreds of objects may be seen on x-ray </li></ul></ul><ul><ul><li>Significant internal injuries </li></ul></ul><ul><ul><ul><li>Objects may enter brain, spinal column </li></ul></ul></ul><ul><ul><li>Nails enter head first (unlike bullets) </li></ul></ul><ul><ul><li>Objects are commonly retained in victims </li></ul></ul><ul><ul><ul><li>Lifetime impairments </li></ul></ul></ul><ul><ul><ul><li>Long term disabilities </li></ul></ul></ul>
    41. 41. Blast Pathophysiology <ul><li>Blast forces and winds </li></ul><ul><ul><li>Direct tissue trauma </li></ul></ul>
    42. 42. Blast Pathophysiology <ul><li>Blast forces and winds </li></ul><ul><li>Amputations </li></ul>
    43. 43. Blast Pathophysiology <ul><li>Amputations </li></ul><ul><li>First: Blast forces shatter bone </li></ul><ul><ul><li>Through bending type force </li></ul></ul><ul><li>Second: Blast winds separate limb </li></ul><ul><ul><li>Avulsion type of mechanism </li></ul></ul><ul><li>Occurs to mainly long bones </li></ul><ul><ul><ul><li>Rarely at joints </li></ul></ul></ul><ul><li>High risk for exsanguination - Rarely re-attachable </li></ul><ul><ul><ul><li>Tourniquet </li></ul></ul></ul><ul><li>Amputation injuries more common among dead & expectant victims </li></ul>
    44. 44. Blast Pathophysiology <ul><li>Amputations </li></ul><ul><li>Tourniquet may be necessary </li></ul>
    45. 45. Management of Blast Situations <ul><li>Triage </li></ul><ul><li>#1 problem in patient management </li></ul><ul><ul><li>Ongoing & continuous </li></ul></ul><ul><ul><ul><li>NOT performed just once ! </li></ul></ul></ul><ul><ul><li>Victims re-evaluated & reclassified at hospital </li></ul></ul><ul><ul><ul><li>Expect high demand for special procedures </li></ul></ul></ul><ul><ul><ul><li>Decisions about admission vs. discharge </li></ul></ul></ul><ul><ul><ul><ul><li>Eardrum rupture NOT strict admission criteria </li></ul></ul></ul></ul>
    46. 46. Special considerations <ul><li>Market place infection </li></ul><ul><ul><li>Higher incidence of Candidema septicemia </li></ul></ul><ul><li>Hepatitis vaccinations </li></ul><ul><ul><li>Blood & body fluids exchange </li></ul></ul><ul><ul><li>Rate 10% Palestinian vs. 1-2% Israelis </li></ul></ul><ul><li>Additional contamination </li></ul><ul><ul><li>NBC material </li></ul></ul><ul><ul><li>Rat poison (coumarin types) </li></ul></ul><ul><ul><ul><li>Anecdotal or myth ? </li></ul></ul></ul><ul><ul><ul><ul><li>Incalculable dose </li></ul></ul></ul></ul><ul><ul><ul><li>Vitamin K </li></ul></ul></ul><ul><ul><ul><li>Factor 7 injection </li></ul></ul></ul>
    47. 47. Psychological & Long Term <ul><li>Psychological Trauma to rescuers </li></ul>
    48. 48. Psychological & Long Term <ul><li>Psychological Trauma to rescuers </li></ul><ul><ul><li>War wounds inflicted on civilians </li></ul></ul>
    49. 49. Conclusion <ul><li>Look at mechanisms of injury </li></ul><ul><li>The increased index of suspicion will lead to: </li></ul><ul><ul><li>Fewer missed injuries </li></ul></ul><ul><ul><li>Increased patient survival </li></ul></ul>
    50. 50. Summary <ul><li>How people die in ground combat: </li></ul><ul><li>31% Penetrating Head Trauma </li></ul><ul><li>25% Surgically Uncorrectable Torso </li></ul><ul><li>Trauma </li></ul><ul><li>10% Potentially Correctable Surgical Trauma </li></ul>
    51. 51. Summary cont. <ul><li>9% Exsanguination from Extremity Wounds -1st </li></ul><ul><li>7% Mutilating Blast Trauma </li></ul><ul><li>5% Tension Pneumothorax - 2nd </li></ul><ul><li>1% Airway Problems - 3rd </li></ul><ul><li>12% Died of Wounds (Mostly infections and complications of shock) </li></ul>
    52. 52. Closing statement <ul><li>Three categories of casualties on the battlefield </li></ul><ul><li>Soldiers who will do well regardless of what we do for them </li></ul><ul><li>Soldiers who are going to die regardless of what we do for them </li></ul><ul><li>Soldiers who will die if we do not do something for them now (7-15%) </li></ul>
    53. 53. References: <ul><li>Mosby’s Paramedic Textbook, revised second edition – 2001, Chapter 18 Mick J. Sanders </li></ul>