Crash-related renal injuries linked to car design

November 1, 2005

Vancouver, British Columbia--Data from a national database of motor vehicle accidents suggest that the interior design of cars may play an important role in causing the renal injuries suffered by crash victims.

Vancouver, British Columbia-Data from a national database of motor vehicle accidents suggest that the interior design of cars may play an important role in causing the renal injuries suffered by crash victims.

Researchers from the University of Washington, Seattle, described the Crash Injury Research and Engineering Network (CIREN) as a unique collaboration among industry, academia, and government with the primary goal of investigating car crashes to identify new ways of improving safety. Jonathan Wright, MD, a resident in urology working with Hunter Wessells, MD, at the University of Washington, presented the group's findings at the AUA Western Section annual meeting here.

Last year, Dr. Wright was a research fellow at the Harborview Injury Prevention and Research Center (HIPRC) in Seattle, one of eight centers nationwide that have contributed both crash and patient data to the CIREN database.

In addition, the degree of any intrusion into the cabin of the car is measured. Dr. Wright cited the example of a patient who had rib fractures, hemothorax, splenic and left renal laceration, and pelvic fractures that could all be directly attributed to the door panel and, specifically, to the intrusion of the armrest into the cabin space.

Dr. Wright and his colleagues reviewed all cases at the CIREN network that involved renal injuries to describe injury characteristics and to look more specifically at some of the crash details to see if specific contact points are commonly involved in car crash-related renal injuries.

Analysis of 2,700 patients in the CIREN database revealed that 125 had renal injuries, and that these occurred most commonly in males under age 30 years. The majority of renal injuries were sustained by the drivers, but 25% occurred in front-seat passengers.

Crash analysis also revealed that about one-fifth of the crashes involved airbag deployment only, and that approximately 50% of the automobile occupants were wearing lap and shoulder belts, with about half of those also experiencing airbag deployment. Ten percent of the car crashes studied showed no evidence of airbag or seatbelt use. About half of the crashes involved frontal impact; the other half, side impact.

"We looked at the amount of intrusion in each car if patients had renal injuries," Dr. Wright said. "As one would expect, with increasing renal injury severity, there was a greater degree of intrusion into the cabin of the car."

Looking more specifically at what contact points in the car were responsible for renal injury, it was apparent that the biggest proportion, a little more than one-third, came from the side interior surface. More than half of those injuries were directly attributable to the armrest. Seatbelts and steering wheels were other common contributors to renal injury.

The study noted that some car door panels have a protruding armrest, while in others, the armrest is recessed.

"Potentially, it is this protruding armrest that is going into the patient's abdomen or chest and causing these injuries," Dr. Wright concluded.

"It appears the predominant mechanism of injury is direct impact, and a lot of this can be attributed to the armrest. Potentially, renal injuries could be prevented through modifications of interior compartment design."