Safer In the Back?

      The fatality rate for American EMS workers is more than twice the national average. Not unrelatedly, many spend large amounts of time riding unrestrained in their ambulances. In the patient compartments, at least, that can be necessary to provide care.

   For several years now, the National Institute for Occupational Safety and Health (NIOSH) has been investigating ways to reduce injuries and deaths among personnel in the patient compartments of ambulances involved in crashes. These involve new kinds of restraints and potential changes to the compartment layout. With the recent completion of the latest portion of its Ambulance Crash Survivability Improvement Project, NIOSH should soon have some pertinent findings to share.

   The good news: It looks, at least preliminarily, like the mobile harness-type restraints researchers have tested in the back don't inhibit providers' ability to tend to their patients.

   "We're still are working to analyze some data, but right now it doesn't look like we're seeing great effects on patient outcomes," says Paul Moore, chief of the fatality investigations team within NIOSH's Division of Safety Research. "We were looking at, for example, whether it takes longer to treat using certain types of restraints than it does with others. There doesn't appear, at this point, to be a big difference."

   There are also some conclusions imminent on the performance of such restraints in a crash: A paper on that is expected to be submitted for journal publication by the end of 2009.

   The lack of negative impact on patient outcomes seems generally in keeping with the findings of a 2008 NIOSH report, Creating a Safe Work Environment for Emergency Medical Service Workers. That paper compared the ability of different-size providers to reach key points on a transported patient using different restraints (fixed and mobile) in a pair of different vehicle configurations (the GSA's standard "Star of Life" and the redesigned model developed by Winter Park, FL, Fire and Rescue in collaboration with Medtec). It found that using harnesses attached by retractable webbing to the forward end of the bench seat allowed even small female providers access to the most-distant Star of Life reach points tested, i.e., the radio controls and suction unit.

   That's great for the patient, but the benefit of such systems to providers may be more questionable. A minimum of 51.5 inches of webbing would be needed per retractor reel, and more than 58 inches for small females to reach the radio controls. That's a lot of play when a crash happens.

   Winter Park's model addressed this by adding a sliding seat forward of the bench seat and moving the patient gurney a bit off-center, toward the provider. It also repositioned the radio closer to the sliding seat. This allowed providers of all sizes to reach the patient's mouth and relocated radio while fully restrained in fixed five-point harnesses—"a substantial improvement," concluded the authors, "when compared to the standard SOL ambulance bench seat and restraint configuration."

   But even that didn't allow everyone to reach everything, so the NIOSH team also tried the retractable harnesses with the Winter Park design. They found, with the sliding seat forward, small female providers needed at least 31.5 inches of webbing on the hip reels and 36.3 inches on the shoulders to reach the suction unit.

   In all, the NIOSH team concluded, "incremental improvements in worker safety can be achieved by modifying the [patient compartment] environment through thoughtful positioning of equipment and worker in conjunction with improvements to personal protective equipment."

   The key word here is incremental. The authors emphasized that they don't advocate standing in a moving ambulance, and aren't suggesting anyone can be fully protected by a mobile restraint while standing more than 50 inches from their seat while in motion. They say only that it's better to be restrained all of the time than none.

   That's likely true, but it's not a given that harnesses are always the better restraint. In studying the development of side-facing seats and restraint systems for the Australian army's Perentie 4x4 vehicle, researchers found that fixed harness systems "have a high probability of serious, if not life-threatening, head, neck and chest injuries" in frontal crashes. That makes simple lap belts, worn low over the pelvis, a better option for bench seat occupants, according to leading ambulance crash researcher Nadine Levick, MD. And, in fact, it's well-known to automotive-safety experts that side-facing seats themselves are a highly unsafe way to transport occupants.

   In an engineering analysis of several recently developed "safety concept" vehicles, including Winter Park's, Levick and colleague Raphael Grzebieta, of the University of New South Wales' Injury Risk Management Research Centre, also cited a lack of technical engineering data or crash testing to demonstrate performance; head strike zone and egress hazards; and anchorages for restraints and equipment not subjected to a 2G impact pulse.

   NIOSH is presently active in some of these areas. An ongoing part of its project involves testing the crashworthiness of equipment mounts. "We've done some quasi-static testing on some common items like defibrillator mounts and cases, oxygen bottle mounts, fire extinguisher mounts, sharps containers, things like that," says Moore. "That gave us some initial idea of the capabilities of the equipment that's out there. The next step will be to actually do dynamic testing." That's on the agenda for 2010, as is potential compartment redesign.

   Clearly, there's a ways to go in optimizing the safety of the patient compartment and moving ambulances in general. The lessons of the automotive safety world haven't yet fully percolated into the ambulance sphere. But everyone, from vehicle manufacturers to the federal government to provider organizations to individual EMTs and paramedics, is interested in getting those death and injury rates down.

   Reason enough, then, to keep after it.

   "We're always interested in finding ways to help people do their jobs more safely," says Moore. "We're not usually limited by our ability to come up with ideas to study. We're only limited by our resources."