Within the last twenty years, the utility of field tourniquets has emphatically taken its place in the forefront of field care for trauma victims. Although the use of tourniquets to control bleeding dates back hundreds of years, prior to the Global War On Terror, they were viewed as relics of another era. Their place was in the operating room; the notion of field application of tourniquets was met with disdain and ominous warning of limb ischemia. However with the Global War On Terror came a cruel new weapon of choice: the improvised explosive device [IED]. IEDs have crippled military vehicles and severed limbs of coalition Soldiers, robbing them of life and limb. As the military strategists sought to adapt novel strategies, fortify their vehicles, and improve detection, military medicine scrambled to find a solution for the injuries inflicted by the enemy's impersonal and devastating weapon of choice. Compressible hemorrhages were found to be among the top preventable causes of death on the battlefield, and tourniquets were soon standard issue to combat medics and eventually, to every Soldier. Tourniquet use impeded blood loss long enough for more of the wounded to reach definitive care and overall survival improved. As is often the case, the civilian trauma care learned from the medical advances on the battlefield and tourniquets soon took their place with law enforcement and even the general public. The Boston bombing and most recently the "Stop the Bleed" campaign bears testament to the recognition and acceptance of the tourniquet as a staple on traumatic field care.
It has been said that a perfect tourniquet does not exist. For this reason, multiple tourniquet products have found their way onto the marked, each with their own strengths and weaknesses. TEMS providers are accustomed to doing more with less, so it comes as no surprise that some these were developed by operators who are steeped in tac-med experience. Below, three of the top products will be discussed, with a focus upon their strengths and weakness, to help elucidate the place of each in the preparation and treatment of worst case scenarios.
North American Rescue's Combat Application Tourniquet, or CAT, emerged early as tourniquets found their way onto the modern battlefield. Currently on its 7th generation, the CAT utilizes a single routing buckle and windlass, along with windlass clip. It is the only tourniquet recommended by the Committee on Tactical Combat Casualty Care and not surprisingly, is considered "the standard" by many. Used by the United States military, the CAT is amenable not only to buddy aid but to one-handed, self-application. While this scenario is rare, it remains worthy of consideration. While evolution of a product is admirable, the multiple generations of CAT could potentially pose administrative or financial challenges to institutions that feel obligated to provide the most current technology. Breakage of the windlass mechanism has been noted in the past, although this issue was with early models. Research has shown effectiveness of the CAT to be markedly reduced after prolonged exposure to the elements, such as daily wear on an individual's "kit." This is not unique to the CAT and could be said of many pieces of equipment, medical or otherwise; nevertheless, it remains an important consideration, as a tourniquet is a high acuity, low volume item - frequently carried but less frequently deployed.
One drawback to the CAT is a lack of continued occlusive forces once the windlass is set; stated another way, once the windlass is set, the tourniquet is as tight as it will be without readjustment. After severance of an extremity, significant muscle spasm occurs initially as the body attempts to control its own volume loss. If a tourniquet is applied promptly, these muscles will likely be rigid with spasm, and may later relax and become more supple. As the windlass has already been set, hemostasis could foreseeably be compromised with muscle relaxation, and require a readjustment or additional tourniquet to arrest blood loss. While touted by many as "the standard," failures of the CAT have been documented, and some studies by the Journal of Special Operations Medicine have illustrated some failures of the CAT. Additionally, it has not been accepted as entirely effective in pediatric or canine patients, which must be considered in the unpredictable world of tactical medicine. While the CAT is heralded as the premiere tourniquet product by many, and with good reason, it is not entirely infallible. A familiarity with its strengths and weakness is critical for the tactical medicine provider to best prepare for the unthinkable.
Pioneered by a former Air Force Pararescueman turned Emergency Medicine physician, the greatest strength of the SWAT-T is its simplicity. SWAT-T, which stands for Stretch-Wrap-and-Tuck Tourniquet; is exactly what its name implies. This device is a length of highly elastic poly-isopropylene material that is designed to achieve hemostasis with its great elasticity once it has been stretched, wrapped, and tucked into itself. The simplicity of this design offers a tourniquet system that can easily be negotiated by a completely uninitiated person. In fact, the SWAT-T has printed upon it a series of rectangles and ovals, with directions that the device should be stretched until these shapes form squares and circles, respectively. Not surprisingly, the SWAT-T can also function as a highly effective pressure dressing; this versatility, and its small size, making it an excellent option for individuals limited on space. While its elasticity does yield constant occlusive force, the SWAT-T can be adjusted without losing pressure by simply pulling it tighter and re-tucking the loose end. The SWAT-T boasts a plethora of case reports, as well as research showing it to be no less effective than other leading tourniquet products; documentation of saves include pediatric patients, canines, and victims of the Boston bombing.
While the simplicity of the SWAT-T is its greatest attribute, some mechanical advantage is lost without a windlass, meaning the SWAT-T does require some strength to appropriately apply. Successful self-application of the SWAT-T has been documented, although some might find it more cumbersome than self-application of a CAT. Despite these drawbacks, many have found the SWAT-T to be their choice for a primary tourniquet option. In fact, case reports have shown it to be effective following failure of a windlass tourniquet. Others have saved space by choosing the SWAT-T to fill the role of both a backup tourniquet and a pressure dressing. It's versatility, small size, and utility for pediatric patients and canine make the SWAT-T an attractive and affordable option for primary or back-up tourniquet.
Also designed by a former Special Forces operator is the relatively new Rapid Application Tourniquet System, or RATS. This system was designed to minimize the need for fine motor skills for successful application. The RATS is a length of [elastic] vulcanized rubber that is attached to a cleat; application is accomplished by creating a "hitch" and pulling the running end through this loop and cinching back against itself. This is followed by circumferentially wrapping the running end around the limb before securing it in a metal cleat. The application is very intuitive, and thus an excellent option for anticipated use by an uninitiated civilian, or [medically] untrained Infantryman or operator. This simplicity also suggests the RATS would be an effective option in extremely low-light conditions. Like the SWAT-T, it takes up very little space, and can be manipulated to easily pack in and around other items within a kit. The RATS manufacturer offers a "sleeve" for carrying this tourniquet made to run the length of the rifle sling. The RATS can easily be fed up into this sleeve, and secured with the cleat, leaving it secured to the operator's weapon, and easily deployed with one hand. The length of the free running vulcanized rubber makes this tourniquet system an option in obese, pediatric, and canine patients; where a windlass tourniquet might prove inadequate. Much like the SWAT-T, the RATS exerts constant occlusive pressure due to the elastic nature of the running end. It's composition of vulcanized rubber suggests significant durability.
Although the manufacturer does demonstrate self-application, some might find it more difficult to self-apply the RATS tourniquet then a prepared windlass tourniquet. The RATS is a relatively new product, and while it does have many case reports of success, it has not been around long enough to carry with it the amount of research or field testing as the CAT and SWAT-T. As with the SWAT-T, the price of the RATS is roughly half of the CAT and it's intuitive design and small size make it an affordable option, particularly when used by the untrained is anticipated.
With the utility of tourniquets in pre-hospital trauma firmly cemented, providers are now afforded the advantage of choosing from multiple options. Fortunately, one need not pick only one. As with any piece of vital equipment, a secondary option can quickly become just as important as a primary one. These three tourniquet options carry their own strengths and weakness. Those that are established have research to bolster their role of managing compressible hemorrhage. Newer options provide innovation but wait upon research to define what piece of the puzzle they may fit. When making choices, a TEMS provider is charged with the responsibility of training and maintaining proficiency with his or her equipment. Whether it is the individual's choice, or departmental policy that determines the tourniquet system; we are all charged with maintaining proficiency with our equipment, and remaining vigilant. Always vigilant.
Aaron Lawrence, DO
Central Michigan University
OEF, 2012-2013, US ARMY
Alec Weir, MD
Department of Emergency Medicine
Central Michigan University
TEMS Physician, Spc. Deputy, Saginaw Co. Sheriff's Dept EST