Checking the S.C.E.N.E. for Airbag Injuries
Check the Deployed Airbag
Did you think about the airbags on the last vehicle crash you responded to? Did you assess the patient for a possible seatbelt injury and an airbag injury? Did you avoid the potential danger zones of the undeployed airbag while inside the vehicle? Did you look beyond the obvious and check for potential airbag injuries?
Occupants involved in motor vehicle collisions may have internal injuries that may not be apparent. Supplemental restraint systems or airbags have saved over 15,000 lives. With the rapid change of advanced vehicle restraints and vehicle safety systems, it's difficult for the average EMS responder to know each vehicle by design and safety features, including airbags. Few of us have ever had a chance to observe a live airbag deployment, but the following tool should raise your airbag awareness.
One key tool that all EMS responders must use to assess for occupants' injuries in today's vehicle collisions is the S.C.E.N.E acronym, which was developed by the National Highway Traffic Safety Administration (NHTSA). The following information should be collected and reported to assess injuries of occupants involved in motor vehicle collisions. I have added some additional information based upon some field reports and surveys from several EMS responders. Please review and share this information with your coworkers at your next training opportunity.
S: Steering wheel deformation
Lift the driver's airbag and look for a bent steering wheel rim. The passenger side airbag (PAB) or its cover may deploy off the windshield, breaking it. Match the "starred" windshield with the "break zone" of the PAB with the mechanism of injury to the occupant's head or body part. Also observe dash deformation from the occupant. This could indicate internal injuries. Check the hands and forearms for incorrect hand position in front of the airbag deployment path. Check to make sure the feet or legs were not placed on top of the dashboard over the PAB.
C: Close proximity of the driver to the steering wheel or the passenger side airbag in the dash
Occupants sitting too close to the steering wheel (approximately 10 inches) or dashboard (approximately 24 inches) are at a greater risk of internal injuries. The potential "lethal zone" of the airbag is in the first 4-6 inches of deployment from its cover housing and occurs with the greatest inflation force. Occupants of short stature or large girth and children are more likely to be seated too close. Check whether any aftermarket communications equipment, like police laptop computers, have been mounted improperly in the deployment pathway of the PAB and become projectiles.
E: Energy of the crash
Twenty or more inches of vehicle crush indicate high crash forces that can cause serious internal injuries. Also, the structural integrity of the "safety cage" should not be compromised and the rest of the passenger compartment should be well intact. Note whether the vehicle was a collapsible unibody vehicle or a full-frame vehicle of larger size. Check for more than one collision.
N: Non-use or incorrect use of safety belts or child safety seats
Non-use of the lap, lap/shoulder belt or a child safety seat as well as incorrect use of these devices can result in multiple impacts and greater probability of internal injuries. Examples of incorrect use that can have serious consequence include: lap belt across the abdomen, shoulder belt under the arm or behind the back, child safety seat not secured properly by safety belt or child not secured in seat properly. Not wearing a seatbelt in combination with precrash braking, often places a person's body directly over the deploying hard cover of the airbag.
E: Eyewitness reports
Verbal reports, photos, and video images of the interior and exterior of the crash vehicle graphically convey the severity of the crash, and can indicate the probability and type of internal trauma. Frontal airbags deploy at approximately 100-200 mph and deflate in 1-2 seconds, and do not protect in secondary crashes. Side impact airbags deploy 3 times as fast, and some vehicles with curtain airbags may deploy in side impacts AND in roll overs and remain inflated for 6-10 seconds. Airbags do not deploy in approximately 30% of vehicle crashes due to the design of the crash, deceleration and other collision forces.
If Airbag Deployed, Vehicles Should Not Be Driven
Since airbags and seatbelts are safety devices, they must meet the Federal Motor Vehicle Safety Standards, FMVSS 209. It is also important to know and recognize the types of liability involving vehicle repairs and damages involved in a collision, even as an EMS responder. Emergency crews arrive at a collision and often find a vehicle's airbags deployed, but the occupants are uninjured. These occupants refuse EMS ambulance transportation and insist on driving their vehicle. They may not realize the airbag has been rendered inoperable. A person involved in an airbag deployment can experience temporary hearing loss, disorientation and confusion, and should be advised against driving any vehicle for at least 2 hours. Because the vehicle's airbags and pretensioners must be replaced after being deployed, EMS responders should advise the law enforcement agency or officers at the scene (and the vehicle driver), to have the vehicle towed. Only a few states have motor vehicle laws regarding the operation of vehicles on the roadway with working supplemental airbag restraint systems. Nonetheless, responders may move the vehicle off the roadway for traffic safety purposes.
More than the 5-10-20 Inch Rule
As a general reminder in working around undeployed airbags, always keep 5 inches distance from a side impact airbag. Most side seat mounted airbags are 5-8 inches wide, 1 foot long and 1-2 feet tall depending on the model. Some curtain airbags are 5-6 feet long, 2-5 inches wide and 12-15 inches tall, so adjust your danger zone. Many new SUVs and minivans have curtain airbags for all three rows, up to 8 feet long! Keep 10 to 12 inches from a driver's airbag, and 20 to 24 inches from a passenger side airbag. If the vehicle has a front flat bench seat with a seatbelt middle position, the PAB may be up to 30 inches by 30 inches large! Always respect the distance the airbag would deploy into. Do not place yourself between the patient and the undeployed airbag. Also, avoid any structural movement, object or equipment in the deployment path of any airbag. Scan for airbag words or labels on the surfaces of the interior of the vehicle. Advise all fire-rescue, EMS and all responder staff of the location of the vehicle's "live" airbags.
New Vehicles Have Pretensioners
Most new vehicles have introduced front seatbelt pretensioners. The first pretensioners appeared in Ford and Dodge full size vans in 1997. They are small pyrotechnic devices similar to an airbag, which deploy in a collision. Some use pyrotechnic propellant, like sodium aizide while others may use a hybrid inflator filled with argon gas under 3,000 psi. The seatbelt pretensions recoil several inches of belt slack, thereby reducing G-forces to the chest and better positioning occupants for airbag deployment. While the pretensioner locations may vary, many of them are located low on the inside of the B-pillar. Some are on the buckle side, like most Ford Ambulances. Some vehicles may also have pretensioners in the rear outboard seating positions and may include them in all occupant seating locations. However, Volvo and Saab may place their pretensioner in the high to middle of the B-pillar for the front seated occupants. To avoid injury from a misfiring pretensioner during a rescue, do not cut or puncture the pyrotechnic device. Unbuckle or cut the seatbelt and keep you hands and fingers away from this device.
Seatbelts and the airbags work together and are timed with precision and accuracy within fractions of a second, called milliseconds. Seatbelts properly position the occupant's body during precrash braking for airbag deployment. The vehicle's airbag computer system senses the type and severity of the crash and deploys the appropriate supplemental restraint safety system for the collision. It is important to remember that maximum effectiveness from the supplemental restraint airbag is accomplished by wearing your seatbelt. The combination of a seatbelt plus an airbag has an 85% reduction of serious injuries to the head and torso. Seatbelts also position the driver for evasive maneuvering, to correct and recover a potential vehicle going out of control, by keeping the driver seated behind the braking and steering imputs for maximum control. Seatbelts and airbags save lives, but be sure to check the S.C.E.N.E.
Contact Dave Long at email@example.com.
Dave Long, Medic, RN, The Airbag Detective
Dave teaches several airbag safety classes originally in conjunction with ABRA Auto Body & Glass and Mitch Becker, I-CAR instructor, and technical consultant since 1998. Dave visits the press week of Detroit Car show in January learning from car manufacturers, auto engineers, and airbag companies about new restraint systems. Dave was the featured speaker on airbags at the EMS Expo conference in New Orleans, National Glass Association conferences, NAFA's Fleet Conference in San Antonio, and NHTSA's Region 3's conference in Virginia. Dave is also a NHTSA CPS technician. Dave is nominated as a consultant by the National Glass Association to CASPA, the Coalition for Auto Glass Safety and Public Awareness. Dave attended Carlite Auto Glass Installation School in Dearborn, Michigan. He is trained by 5 automobile engineers to help promote safe windshield installation practices and cracked windshield repair for the automobile owner, including taking the I-CAR Auto Glass Replacement course. He has met twice with the NHTSA Special Crash Investigation Team in Washington, DC. Dave teaches 17 classes in all for responders and can be reached at firstname.lastname@example.org.