Little Kids in Big Crashes The Bio-mechanics of Kids in Car Crashes. Lisa Schwing, RN Trauma Program Manager Dayton Children s

Transcription

1 Little Kids in Big Crashes The Bio-mechanics of Kids in Car Crashes Lisa Schwing, RN Trauma Program Manager Dayton Children s

2 Very Little Research There has been very little research on the forces a crash has on a child s body. Most research has occurred on scaled down models of the adult body.

3 Kids are not little adults Because children are smaller than adults, traumatic forces in children usually affect a larger region of the body. Multisystem injuries are more common among pediatric patients. High incidence of pulmonary contusion, liver and spleen injuries. Compact - organs are more tightly packaged. Most often, less fat, less muscular, therefore less protection.

4 Speed vs Velocity Kenetic Energy = ½ mass X velocity E=½ MV 2 When mass is doubled, so is the energy. When velocity is doubled, energy is quadrupled. 2 Bottom line speed kills!

5 Children have big bobble heads In comparison to body size, the child s head is larger in size and weight. A child s neck ligaments are weaker.

6 Child Thrown from a Vehicle During a Crash Any child that goes airborne up to the age of 10 will land on their head.

7 The Child s Skull is Thinner Predisposing the skull to fractures that are often accompanied by epidural or subdural bleeding. Head injury is the number one cause of death in children involved in car crashes.

8 Epidural or subdural bleeding on the Brain Can be fatal An epidural bleed is usually the result of a torn artery (the middle meningeal artery) in the brain that bleeds under pressure.

9 A Child s Ribs are Made of Cartilage. Ribs of a child are horizontal and have little calcium. Fractures are difficult to identify, but underlying organs are easily injured. Chest radiograph taken 6 days after injury reveals multiple healing fractures at costovertebral junction and lateral ribs bilaterally. Adult ribs are at an angle, are calcified and hard and provide better protection in a crash.

10 Lungs are Smaller and Respiratory Rates Higher The lungs have disproportionately smaller inside surfaces for oxygen exchange compared to an adult. Depleted oxygen and fatal chemical changes in the blood occur very quickly in children without adequate oxygen.

11 What we do know Abdominal Muscles are less developed. Baby Buda belly Think potential for multisystem injuries.

12 Motor Vehicle Crashes Put Children at Risk for Abdominal Injuries High velocity crashes cause extreme energy transfer to the body. The combination of tightly packaged abdominal organs and in some cases ill fitting safety restraints put a child at increased risk for abdominal injuries.

13 Excessive Energy Transfers to a Small Area Chance fracture Flexion injury around the lap belt.

14 Airbag injuries to children

15 Back to the math E=½ MV 2 5 kg baby 50 mph 921 pound force/foot Zero chance you will hold this child in a 50 mph crash.

16 Chest and Abdominal injuries Chest and Abdominal Injuries are the second leading cause of death in pediatric trauma associated with car crashes. Because the physical exam is often not reliable and the history may be incomplete, missed injuries can lead to increased morbidity and mortality.

17 FAST Exam in Children Negative predictability fairly reliable Positive predictability about 56% and uncertain due to modest sensitivity. Varying study results

18 Ruptured Spleen Goal Children keep their spleens. The 2 children requiring splenectomies due to trauma done at DC in the last 12 years were both in MVC s and both inappropriately restrained. (3yo in booster and 6 yo in seatbelt ) Both had ruptures with massive bleeding. Both had multisystem injuries with ISS >40. Both recovered completely.

19 Blunt Abdominal Injuries Hollow Organs Hollow organ injuries usually require urgent surgical intervention. Esophageal and stomach Bowel Bladder

20 Skeletal Differences Children have incomplete bone calcification. Children s bones are still growing. Injuries to growth plates can arrest bone growth.

21 Penetrating vs. Blunt Abdominal Trauma Penetrating trauma accounts for < 4% of all injuries seen at Dayton Children s. Blunt trauma is common. While falls are the most common cause of injury, severe injuries related to blunt force trauma are usually associated with motor vehicle crashes (not accidents) or children hit by a car while riding a bike or walking Percent of Injury Types at Dayton Children's 1 Burns Penetrating Injuries Blunt Injuries

22 How bad was the crash? Delta v Consider the crashworthiness of the vehicle, the passenger characteristics, and restraint usage. Factor in the speed change of the vehicle as a result of the crash known as the Delta v. This is the measure of the severity of the impact. However, mechanism is not always a factor in the severity of the injury and at Dayton Children s was found to be a poor indicator for predicting injuries.

23 Disbursing the energy in a crash When the energy transfer is isolated to one line or one spot, the impact to that line or spot is greater. Take the energy and spread it out across a larger surface and the energy transfer to any one spot is. A helmet absorbs the energy, spreads it out and protects the head much like seatbelts protect the body.

24 Seatbelt stats Children 4-8 years old restrained in seatbelts are 3 times more likely to be admitted for injuries from a motor vehicle crash than children from birth-4 years. They are too big for car seats and too little for seatbelts. Ohio legislators passed a law October 7, 2009 requiring booster seats for all children 4 to <8 years-of-age and shorter than 4 9. No Perfect

25 What is wrong here? The neck The lap belt / buckle The position of the legs

26 What s wrong here The lap belt The shoulder harness The 5 point restraint buckle Transfer of crash energy to a single area

27 What s wrong here? Too small/young for seatbelts. Shoulder strap across abdomen. No neck protection.

28 What s wrong here? Nothing

29 Seat Belt Injury = Tier II Trauma Activation Though seat belts contribute to a number of predictable injury patterns, proper use of seat belts is statistically the single best prevention for motor vehicle crash fatalities. Note the lack of shoulder strap markings.

30 What s wrong here? Lucky baby involved in a roll over crash.

31 5-Point Restraints Spread the Crash Impact

32 Seatbelt Sign Dayton Children s admitted 65 children with positive seatbelt signs in the last 2 years. The most common injuries associated with seat belt sign: deaths 0 spleen lacerations 11 liver laceration 1 renal lacerations 4 perforated bowel 1 intracranial bleeds 3 concussion 8 skull fracture 2 lumbar fracture 1 femur fracture 5 humerus fracture 3 pelvis fractures 4 pulmonary contusions 4 rib fractures 3 clavicular fracture 3 facial injuries 3 Seat Belt sign with associated lumbar compression fracture

33 There is No Substitute for Good Judgment

34 Kids can Survive Most Car Crashes if Properly Restrained

35 Summary Researchers are striving to develop accurate ways to predict a child s injuries in a motor vehicle crash. Kids are not little adults. Prevention is key. Thank you for all you do!