VII. Physicians' Conference on Medical
That Warrant Turning off an Air Bag (July 1997)
At the request of NHTSA, the Ronald Reagan Institute of Emergency Medicine at George Washington University conducted a National Conference on Medical Indications for Air Bag Disconnection on July 16-18, 1997. The purpose of the conference was to make recommendations on specific medical indications, i.e., conditions, that might warrant disconnecting an air bag. The conference consisted of a panel of representatives of 17 medical specialty societies or organizations. NHTSA selected the societies and organizations, in consultation with the University, based on the types of medical indications that vehicle owners were citing in their letters to NHTSA as possible justification for air bag disconnection. Each society and organization, in turn, selected a representative to attend the conference. Among the specialty areas and types of physicians represented were cardiology, ophthalmology, otolaryngology (ear, nose and throat), obstetrics and gynecology, physical and rehabilitative medicine, general surgeons, plastic and reconstructive surgery, orthopaedic surgery, neurological surgery, pediatrics, geriatrics, and emergency physicians. The American Medical Association was also represented.
The agency arranged for this conference for several reasons. First, informal agency conversations with emergency room physicians and surgeons familiar with the trauma caused by motor vehicle crashes had suggested to the agency that very few medical conditions warrant turning off an air bag. Second, several commenters on the January NPRM urged that the medical profession be enlisted to help identify those conditions. The American Academy of Pediatrics said that such professional guidance was needed to educate dealers, repair businesses and some parts of the medical community itself about the circumstances under which it is appropriate to turn off an air bag. Advocates for Highway and Auto Safety urged that a panel of medical experts be convened to examine each vehicle owner request to turn off an air bag based on medical reasons.
While the agency does not believe that it is necessary or desirable for a panel of medical experts to review each such request, the agency did agree that general authoritative advice is needed to answer the concerns of some vehicle owners about air bags and help guide their actions. Since individuals with particular medical conditions can be expected to consult their physician prior to deciding whether to have an on-off switch installed, the medical profession also needs some guidance on when deactivation would be indicated.
In preparation for the conference, the representatives reviewed the available medical and engineering literature about air bag technology and injury risk and prevention. At the conference, the 17 representatives were divided into subpanels. Based on their literature review and clinical experience, the subpanels addressed each medical indication with respect to seven factors: known data, unknown data, recommendation, level of confidence in the recommendation, rationale for the recommendation, specific concerns about the recommendation, and stakeholders. The entire panel then discussed the work of the subpanels and adopted final recommendations.
General panel conclusions.
Air bags are effective lifesavers whose benefits exceed the risks for most of the medical conditions considered by the panel. A medical condition does not warrant turning off an air bag unless the condition makes it impossible for a person to maintain an adequate distance from the air bag. NHTSA believes that 10 inches is an adequate distance.
Excerpts from the panel's specific recommendations follow, beginning with the recommendations regarding the medical indications most commonly cited by persons who have written to NHTSA requesting deactivation based on a medical indication. Unless specifically indicated, the recommendations relate to drivers.
Medical indications not warranting disconnection of air bags.
Medical indications most commonly cited by vehicle owners.
The panel recommends air bag not be disconnected for persons with osteogenesis imperfecta.
While there is little population-based data in the crash experience of this group, it is anticipated that the injury risk to these persons is higher without an air bag and proper restraint than with an air bag.
For persons with osteoporosis, arthritis, and other skeletal conditions, air bags should not be disconnected unless the person cannot sit back a safe distance from the air bag.
Persons with specific conditions, such as ankylosing spondylitis, may have a relatively stiff spine and thus may be unable to place themselves an acceptable distance from the steering wheel while driving. Other than in this specific circumstance, persons with osteoporosis and types of arthritis are generally benefitted by the presence of an air bag.
There is no evidence to support disconnecting airbags for occupants who have pacemakers, implantable defibrillators, or similar devices.
Pacemakers and similar hardware are specifically designed to withstand impact. The forces associated with air bag deployment are typically distributed throughout the chest and are not directed at one specific area. The impact suffered without an air bag may in fact be more severe and more localized than that with an air bag. Clinical experience does not demonstrate any significant concern about the effects of air bag deployment on this type of hardware when properly installed. As forces to the chest in areas directly contacted by seatbelts may exceed forces from air bags, it is important the belts be placed properly and not directly over these devices.
We recommend that persons who have undergone median sternotomy not disconnect air bags.
Uneven pressure on the chest can harm a patient with a recent median sternotomy because the external wound may be opened. An air bag does not cause this uneven force; seatbelts or striking an object like a dashboard can cause this uneven force.
We recommend not to disconnect air bags for patients with these chronic lung diseases.
There is no risk of oxygen deprivation during air bag deployment because of the quick deflation of the device. There is some equivocal evidence to suggest that the chemical irritants produced may precipitate bronchospasm in persons with asthma. However, there is no evidence to suggest that this phenomenon is occurring with any greater frequency in the presence of air bags. There is no reason to suspect that persons with any type of chronic lung disease will be adversely affected by an air bag deployment sufficiently enough to justify disconnection of the device.
We are not able to determine an absolute cut-off height and weight for disconnection of air bags.
Short stature is a common area of concern for the public in regard to air bag deployment. As proximity to the air bag is the major issue, the passenger-side air bag should not be disconnected for a passenger of short stature. Beyond just short stature, weight, arm length, and leg length also play important roles in driver positioning. We know that a disproportionate number of the deaths attributed to air bag deployment have occurred in persons of short stature. However, of the 150,000 estimated air bag deployments involving persons of short stature, only 14 are known to have been fatal.
Some of the less commonly cited medical indications.
There is no reason to recommend disconnection of air bags for persons wearing eyeglasses.
There are a number of anecdotal cases of eye injuries after air bag deployment, both with and without eyeglasses. Eyeglasses may, in fact, be protective during air bag deployment. There is no obvious increased risk of injuries in the presence of eyeglasses; moreover, impact with the steering column or dashboard may be more dangerous to someone wearing eyeglasses than impact with an air bag. Persons who need eyeglasses should wear them to drive and should not have air bags disconnected solely because of the eyeglasses.
We recommend not to disconnect air bags for persons with hyperacusis or tinnitus.
...(T)he phenomenon of hearing loss has not been noted to occur due to air bags. The specific conditions of hyperacusis and tinnitus are not associated with hearing loss and persons with these conditions would have no greater likelihood of hearing loss from air bag deployment than any other persons. Some persons with tinnitus report that noise triggers attacks of tinnitus; however, it is difficult to separate the noise of an air bag from the noise of a crash in many situations.
Advanced age by itself does not suggest the need for air bag disconnection.
It is known that older persons are at greater risk of injury in all types of crashes. The data suggests that air bags may be less effective in the older population although the cause of this finding is unclear. There is no evidence to suggest that advanced age by itself, in the absence of other potential risk factors examined here, warrants air bag disconnection.
With respect to passenger seat occupants in general, the conference participants said:
Under most circumstances, with the notable exception of infants in rear-facing infant seats, the person in the passenger position can be made safe from inadvertent injury by the use of proper restraint and placement of the seat in the most rear position. Certain vehicles with bench seats may complicate this issue and may need to be considered carefully on a case-by-case basis.
Medical indications warranting disconnection of air bags.
For persons with osteoporosis, arthritis, and other skeletal conditions, air bags should not be disconnected unless the person cannot sit back a safe distance from the air bag. (20)
If capable of being positioned properly, persons with scoliosis should keep air bag connected in their vehicles.(21) (Emphasis added.)
This specific condition might make it impossible for a person to sit upright and away from the air bag. This very small portion of the population of persons with scoliosis might be candidates for disconnection. It must be remembered that a person sitting far forward in either the driver or passenger seat is also at increased risk of injury from other structures (steering column, dashboard) in front of them.
For persons in wheelchairs the decision to allow disconnection of the air bag should be handled on a case-by-case basis. Disconnection may be needed if installation of special equipment requires removal of the air bag. If wheelchair installation or steering column configuration does not necessitate air bag removal, we recommend not to disconnect air bags.
In persons with achondroplasia we recommend allowing disconnection of driver-side air bag only if the person is unable to sit back from the air bag.
Persons with significantly congenitally shortened limbs may be required to sit very close to the steering wheel in order to operate a vehicle. In this situation, pedal-extenders will offer limited assistance as the arms are also affected. However, there is no reason to disconnect the passenger-side air bag for an occupant with achondroplasia.
Disconnection of the passenger air bag is warranted if a person with this specific condition cannot reliably sit properly aligned in the front seat, such as in those with developmental delay.
Children and adults with severe developmental delay, including some with Down syndrome, may be incapable of consistently maintaining a position away from a passenger-side air bag. If these individuals cannot ride in a back seat, air bag disconnection may be warranted.
While there is no known data on this specific situation in relation to air bags, atlantoaxial instability is present in 20% of persons with Down syndrome. This instability creates the clear risk of atlantoaxial subluxation. Persons with this condition should clearly sit properly restrained in the back seat of a vehicle. In situations in which they must sit in the front seat, air bag disconnection may be warranted because of the risk of cervical injury, particularly if these individuals have developmental delay which prevents them from consistently maintaining proper positioning.
The panel recognizes that there are a few specific medical conditions in which infants and young children must be in the front seat for monitoring by the adult driving. In such situations, the passenger side air bag may need to be disconnected.
Parents are frequently concerned that they will be unable to properly monitor their infants if the infants are in the back seat without an adult. The American Academy of Pediatrics has clearly recommended that infants without underlying medical conditions can safely ride alone in the back seat properly restrained in a rear-facing restraint. The data shows that in the absence of an air bag, the injury risk in the back seat is 30% less than the risk in the front seat. The panel recognizes that certain vehicles do not have back seats. In these vehicles the option of on-off switches is already available. Monitoring of certain infants may require placement of the car seat in the front passenger seat when the only adult in the vehicle is the driver. These situations may warrant air bag disconnection or an on-off option. Parents should clearly recognize that distraction while driving significantly increases the risk of a crash. Ideally, if a child needs attendance in a vehicle, someone other than the driver should be available. It is anticipated that the American Academy of Pediatrics will make recommendations regarding which specific conditions warrant close monitoring while driving.
20. NHTSA believes that the safe distance for drivers with osteoporosis/arthritis is the same as that for persons without any medical indications, i.e., 10 inches between the center of the driver air bag cover and the center of the driver's breastbone.
21. NHTSA defines "properly positioned" to mean positioned so that there is at least 10 inches between the center of the air bag cover and the center of the driver's breastbone.
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