Car crashes are a significant cause of trauma death worldwide. Aortic injury is the cause of death in somewhere between 16% and 35% of these crashes (in the US). Over the years, automobile safety through engineering improvements has been rising. A recent poster presented at EAST 2012 looked at the effect of these improvements on mortality from aortic injury.
The authors analyzed the National Automotive Sampling System – Crashworthiness Data System database (NASS-CDS) for car model years dating from 1994 to 2010. They included any front seat occupants age 16 or more. Over 70,000 cases were reviewed.
- Overall mortality from aortic injury was 89%
- 75% of deaths occurred prior to arrival at a hospital
- Risk for suffering an aortic injury was statistically associated with age >=60, being male, being the front seat passenger, position further back from the steering wheel, and ejection from the vehicle
- The injury was more likely to occur when speed was >= 60mph, impact occurred with a fixed object, and in SUV vs pickup truck crashes
- Newer cars protected occupants from aortic injury in side-impact crashes, but the incidence actually increased in frontal-impact crashes
Bottom line: Aortic injury will remain a problem as long as we find ways to move faster than we can walk. Engineers will continue to make cars safer, but the increase in aortic injury in frontal impact in late model cars is puzzling. This phenomenon needs further analysis so that safety can be improved further. Trauma professionals need to keep this injury in mind in any high energy mechanism and order a screening chest CT appropriately.
Reference: Aortic injuries in new vehicles. Ryb et al, University of Maryland and Johns Hopkins. Poster presented at EAST Annual Meeting, January 2012.
All trauma professionals are keenly aware of how often alcohol is involved in automobile crashes. Something you may not know is that one third of drug tests for other substances are positive in drivers involved in car crashes!
There has been a 5 percent increase in the number of positive drug screens in drivers over the past 4 years. The drugs range from hallucinogens to prescription pain medications.
Seventeen states have enacted legislation making it illegal to drive while on various types of legal and illegal drugs. However, these laws are difficult to enforce because:
- They are more difficult to detect, both by law enforcement at the scene and in the hospital
- We don’t know a lot about the impact of these drugs on driving performance
- A positive drug screen does not tell us when the substance was taken and if it is at a significant level
Drug screens are typically obtained in the ED in seriously injured drivers. It’s a good idea to order one in any patient with a significant head injury. This allows the clinician to guess (and it’s just a guess) that the medications may be impairing the mental status exam. Any patients who have a positive screen should have a documented chemical dependency evaluation and be provided with referral information to get further help.
Reference: National Highway Traffic Safety Administration
An Airbag In Your Seatbelt?
Ford is introducing rear seat belts with built-in airbags in its 2011 Explorer SUV. It’s a $395 option that is designed to diffuse crash impact across a wider area of the chest. This is particularly important when strapping children in the back seat.
The system uses a cold gas system, unlike the heated gases in standard airbags that can cause minor burns. Ford plans to roll it out to additional models in later model years.
The video shows how the system works in slow motion. Very “cool”!