James Stratton

Occult abdominal injuries to airbag-protected crash victims: a challenge to trauma systems.

A multidisciplinary, automobile crash investigation team at the University of Miami School of Medicine, William Lehman Injury Research Center of Jackson Memorial Hospital/Ryder Trauma Center in Miami, Florida, is conducting a detailed medical and engineering study. The focus is restrained (seatbelts, airbag, or both) occupants involved in frontal crashes who have been severely injured. More than 60 crashes have been included in the study to date. Analysis of the initial data supports the general conclusion that restraint systems are working to reduce many of the head and chest injuries suffered by unrestrained occupants. However, abdominal injuries among airbag-protected occupants still occur. Some are found among occupants who appeared uninjured at the scene. Case examples are provided to illustrate abdominal injuries associated with airbag-protected crashes. The challenges of recognizing injuries to airbag-protected occupants are discussed. To assist in recognizing the extent of injuries to occupants protected by airbags, it is suggested that evidence from the crash scene be used in the triage decision. For the abdominal injury cases observed in this study, deformation of the steering system was the vehicle characteristic most frequently observed. The presence of steering wheel deformation is an indicator of increased likelihood of internal injury. This may justify transporting the victim to a trauma center for a closer examination for abdominal injuries.

HEART INJURIES AMONG RESTRAINED OCCUPANTS IN FRONTAL CRASHES

The William Lehman Injury Research Center has conducted multi-disciplinary investigations of one hundred seventy-eight crashes involving adult occupants protected by safety belts and air bags. When used in conjunction with National Accident Sampling System/Crashworthiness Data System (NASS/CDS) they provide insight into the most severe injuries suffered by restrained occupants in frontal crashes. Heart injuries are rare, but when they occur they are usually life threatening. NASS/CDS shows that heart injuries comprise about 0.2% of the injuries in frontal tow-away crashes, In the NHTSA file of Special Crash Investigations (SCI) of air bag cases, heart injuries are reported in 1% of the occupants over 15 years of age. Twenty-five percent of the fatally injured occupants had heart injuries and 83% of those with heart injury died. In the Lehman Center cases, heart injuries are present in 5.1% of the cases. Forty percent of the fatally injured had heart injury, and 78% of the victims with heart injury died. This paper suggests two additional triage criteria, based on observations from multi-disciplinary studies. These include: (1) passengers in 2-point belts and crashes of 25 mph or higher, with the lap belt unfastened or with the seat full forward; (2) drivers in crash conditions which delay the air bag deployment or permit the driver to be close to the air bag at deployment. (A) For the covering abstract see IRRD 893297.

Neck injuries caused by automatic two-point seat belts: an analysis of four cases.

Although seat belts significantly reduce the extent and severity of injuries sustained by motor vehicle occupants, seat belts are known to be associated with chest and abdominal trauma. Less commonly understood are severe neck injuries caused by the use of two-point automatic shoulder harnesses without concurrent use of a manual lap belt. Such injuries may include cervical spine fractures, craniocervical dislocations and rarely decapitation. Recognizing patterned injuries caused by seat belts and the ability to correlate autopsy findings with the circumstances surrounding the death will allow for correct interpretation of seat-belt related trauma. The four cases described detail fatal neck injuries as a result of improper seat belt use in which an automatic two-point shoulder harness was used without a manual lap restraint. In two of the cases, the victims were decapitated.

AIRBAG PROTECTED CRASH VICTIMS - THE CHALLENGE OF IDENTIFYING OCCULT INJURIES

At the Ryder Trauma Center of the Jackson Memorial Hospital in Miami, Florida, a multidisciplinary, automobile crash investigation team is conducting a detailed medical and engineering study. The focus is on restrained (seatbelts and/or air bag) occupants involved in frontal crashes who have been severely injured. More than 60 such crashes have been included in the study to date. Initial data analysis indicates that restraint systems are working to reduce many of the head and chest injuries which unrestrained occupants suffer. However, internal injuries among air bag-protected occupants may be unrecognized in the field. Also, extremely high severity crashes are presenting trauma management challenges. This paper provides case examples to illustrate types of chest and abdominal injuries associated with air bag cases. To assist in recognizing the extent of injuries to occupants protected by air bags, it is suggested that additional evidence from the crash scene be used in the triage criteria. For the occult chest/abdominal cases in the Jackson study, deformation of the steering wheel was the vehicle characteristic most frequently observed.

Air Bag Induced Injury Mechanisms for Infants in Rear Facing Child Restraints

The National Highway Traffic Safety Administration (NHTSA) Special Crash Investigations database contains twelve completed cases of child fatalities in rearward facing child seats caused by deploying air bags. Three of these are now available for examination. An additional two cases were investigated by the William Lehman Injury Research Center at the University of Miami School of Medicine. These five cases are examined to evaluate the crash environment, injury mechanisms, and circumstances which caused the child to be in front of the passenger side air bag. Four of the cases were crashes with impacts with the side of other cars with crash severities less than 15 mph. The predominate injury mechanism was brain and skull injury from a blow transmitted to the rear of the head through the child seat back.In one case, the force to the head was transmitted downward, directly from air bag contact. In this case, the infant showed no sign of injury at the scene, and there was no damage or displacement of the rearward facing child seat. The child died 24 hours later of brain injuries. Inaccurate, incomplete, and inadequate warnings existed regarding the use of rearward facing child safety seats during the time period in which the crashes in this investigation occurred (1995-1996). (A) For the covering abstract of the conference see IRRD 899572.

Using CIREN Data to Assess the Performance of the Second Generation of Air Bags

The paper examines the data from the William Lehman Injury Research Center (WLIRC) that is a near census of crashes in the Miami-Dade region with occupants that appear to be severely injured. The WLIRC at the University of Miami has investigated more than 200 frontal crashes in which the occupants were protected by air bags. Because the WLIRC cases are a census of cases in the Miami-Dade County rescue area with suspected severe injuries, they may be used to rapidly identify benefits of second generation air bags. The database has no child fatalities due to the air bag. Four cases of 2nd generation air bags with good protection in drivers in crashes well above 35 mph, and for the 2nd generation air bags, unrestrained drivers appear to have better protection in a high-severity barrier-type crash than unrestrained passengers.