Major Incidents, Training, Trauma

Rapid Deployment of Tourniquets in the Field, on Yourself and on Others

Issue 40 and Volume 41.

Military and law enforcement personnel involved in tactical casualty care, caring for themselves and others on the frontlines, stress the need for all emergency responders to be familiar with lifesaving tourniquets and to practice self-application, single-handed and two-handed application techniques so they can master tourniquet application if they’re severely wounded in a dynamic or active threat environment, or if they have to apply a tourniquet by themselves or in conjunction with others. Emergency responders have to be familiar with tourniquet application because it’s now a primary tool in trauma kits.

This article is not intended to argue for tourniquet use. There are currently several guidelines, articles and publications extolling the benefits, safety and effectiveness of tourniquet use for controlling life-threatening hemorrhage.1-4

It’s also not intended to recommend a specific device over another—there’s adequate literature to appropriately educate readers on tourniquet device design safety and efficacy considerations. It’s each organization’s responsibility to conduct its own due diligence in researching and evaluating the devices it decides to procure.

Rather, the purpose of this article is to provide experienced best-practice suggestions and techniques for applying tourniquets under critical, stressful and sometimes less-than-ideal conditions.

DEVICE TYPES

One of the critical tasks required for responders is to control life-threatening bleeding. Although there are several individual skills that will accomplish this task, we are focusing here on how to best apply a tourniquet to control life-threatening extremity hemorrhage.

A tourniquet is simply any device that’s placed around an extremity and produces enough external circumferential pressure to stop arterial blood flow beyond the device. Tourniquets can be commercially produced (such as the CAT or SOFT-T), pre-constructed (e.g., a cravat and dowel rod), or improvised from materials in the environment.

A tourniquet requires some form of mechanical assistance such as a windlass rod or ratchet system in order to occlude arterial flow in larger extremities; sufficient circumferential pressure can’t be generated with anything that can only be tightened by pulling with bare hands.

The device shouldn’t generate excessive pressure or apply pressure over a very narrow width as that risks inducing crush injury to the underlying nerves and vessels.

Figure 1: Hemorrhage control techniques allowing at least one free hand

APPLICATION FACTORS

When operating in a dynamic threat environment or if trained to operate in the warm zone, it’s advisable to apply only those medical interventions required to stabilize the casualty while constantly remaining vigilant to the developing situation. The rescuer must be prepared to stop whatever they’re doing and move themselves and the casualty to a safer location as required by the situation. There are two primary methods of applying tourniquets in dynamic threat environments: hasty and deliberate. A “hasty” application is used when the patient’s condition or a dangerous situation doesn’t allow for the injured extremity to be exposed and examined under adequate lighting. In these cases, the tourniquet is applied directly over clothing as high as possible on the extremity to rapidly achieve temporary hemorrhage control.

Responders must understand that bulkier clothing (e.g., a firefighter’s turn-out gear or a tactical officer’s gear-laden pants) is more likely to reduce the tourniquet’s effectiveness. Also, the more the clothing is moved, the greater the chance that the tourniquet may be inadvertently loosened or dislodged. Solid items (e.g., equipment, knives, phones, and keys) located between the tourniquet band and extremity may render the tourniquet completely ineffective or cause tissue damage.

A “deliberate” application is more effective than a hasty application because the tourniquet is applied to an injured extremity directly against the skin proximal to the wound (i.e., between the trunk and the injury, not between the injury and the end of the limb) and not directly over or immediately above/below a joint. It should be used whenever there’s sufficient time for the provider to expose the injured limb and examine it under adequate lighting conditions.

A properly applied tourniquet creates a great deal of pain, so removing tourniquets that aren’t necessary will alleviate the casualty’s discomfort. Trained medical personnel may find it more effective to convert hasty tourniquets to deliberate tourniquets for injuries requiring continued tourniquet use.

Tourniquets placed by non-medical responders need to be evaluated by a trained medical responder as soon as it’s feasible. Also, a tourniquet applied by a non-medically trained bystander or first responder may not be required to control hemorrhage. Many soft-tissue injuries look bad and appear to have life-threatening bleeding, but in reality don’t require a tourniquet. In addition, if the tourniquet was applied over clothing or the casualty was subsequently moved, the device may have loosened, become dislodged, or it wasn’t sufficiently tightened to begin with.

Figure 2: Tourniquet preparation

PREPARATION & APPLICATION

There are several ways that you can temporarily stop the flow of massive hemorrhage as you reach for and apply your tourniquet. You can use direct pressure with one hand, fist, elbow or one knee. (See Figure 1.)

Although there are a multitude of commercially designed tourniquet devices available on the market, this article focuses primarily on the two tactical tourniquets recommended by the Committee on Tactical Combat Casualty Care: the Combat Application Tourniquet (CAT) and the Special Operations Forces Tactical Tourniquet (SOFT-T).

Both the CAT and SOFT-T feature a windlass rod that’s used to tighten the tourniquet after its band is as tight as possible. The primary difference between the two is that the CAT features a U-shaped area that the windlass rod is secured in, and a Velcro closure that’s placed over the top of the lock-in area as a safety to keep the windlass rod from being knocked loose. The Velcro tab is also where you can write down the time of tourniquet application.

The SOFT-T Wide features a 1 ½” tourniquet strap, a curved steel clip buckle and a high-strength aluminum bar with circular channels on each end that allow you to lock either end into the V-shaped locking triangle on the band.

To prepare a windlass tourniquet for application, it should first be removed from its packaging and stretched straight out. Approximately 6″ of the running end of the tourniquet should be threaded through the buckle assembly, and the threaded loops should be folded under the buckled and windlass assembly for storage. (See Figure 2.) Figure 3 demonstrates self-application to an arm; and Figure 4 demonstrates leg application.

The reality of applying tactical tourniquets is that they hurt: from both the mechanical pinch and pressure of the actual device and the ischemia occurring in the distal part of the limb. Providers should be prepared to address this pain, and in hypovolemic and slightly hypotensive casualties, you should consider micro-dose ketamine as a primary pain control agent.

Figure 3: Self-application to an arm

TIGHTENING NUANCES

Although applying a strap-and-windlass tourniquet seems intuitive and simple, the reality is that unless the rescuer pays close attention to detail and understands basic application principles, it’s easy to inadvertently introduce errors that prevent successful application.

Two common errors that have been found to occur with both the CAT and SOFT-T include failure to tighten the band sufficiently prior to activating the windlass rod and holding the windlass rod as an anchor point while tightening the band.

To be truly effective, the band must be applied as tightly as possible. If two fingers can easily slide between the extremity and the band, then it isn’t tight enough. (See Figure 5).

Inexperienced rescuers often believe that excess slack in the band can be taken up with the windlass rod. However, the laws of physics and mechanical engineering impart limitations on these devices to overcome human error.

If the rescuer has to turn the rod more than 3–4 times, then the tourniquet is unlikely to be effective in creating arterial occlusion pressures by itself. Additionally, this may create unnecessary band deformity that causes the pressure to be applied in an increasingly narrow width.

Another common tightening error is utilizing the windlass rod as an anchor point while tightening the band. We frequently observe individuals pulling counter traction with the rod while tightening the band through the buckle. This technique usually creates slack in the band just below the windlass rod. If this is done, the first couple of turns of the rod will be needed to take up this slack before it can actually begin to tighten the band itself.

Figure 4: Application to a leg

CAT BUCKLE DESIGN

There are distinct differences between the GEN 6 CAT and the GEN 7 CAT. (See Figure 6A and 6B.) The GEN 6 has two slits in the friction adapter buckle that, when used simultaneously, create a secondary mechanism to secure the band to prevent accidental dislodgement during vigorous casualty movements.

Initially, the manufacturer recommended that if the original version of the CAT was applied to an upper extremity, the band only needed to be routed through a single slit, while if the CAT was applied to a leg, the band should be routed through both slits. (See Figure 6C and 6D.) Those recommendations were subsequently revised to describe routing the band through a single slit when applying the CAT with one hand and routing through both slits when using two hands.

This change was intended for rescuers to understand the importance of using a secondary securing mechanism (locking buckle) to supplement the primary securing mechanism (Velcro band) to prevent inadvertent release of the device when moving casualties through a vigorous evacuation process. Unfortunately, this created some confusion for most individuals receiving initial training on the CAT.

The manufacturer has also recommended that tourniquets be carried in the “quick launch configuration” with the band routed several inches through a single slit and then adhered to the Velcro. In this manner, the CAT can be quickly applied by passing the open loop over the injured extremity to the desired location and then tightened down. Many individuals remove the band from the slit, route the band around the extremity, then pass the band back through a slit and tighten down. We don’t recommend this because this technique adds additional steps to an already complex task and, under sympathetic stimulation, when a rescuers’ adrenaline level is high, increasing the complexity of a task increases the chance the task won’t be accomplished correctly, especially when the individual has had minimal training.

Attempting to route the free-running end through the slit in a buckle under these conditions also created another inadvertent opportunity to induce human error.

We’ve also observed students inadvertently creating failure points in two ways with the GEN 6 buckle: The first is when the rescuer pulls traction off-center, causing the buckle to become rotated. This causes the Velcro band to lodge in the narrow end of the slit, and causes a situation whereby the band can’t be quickly dislodged under duress. (See Figure 6E.)

The second failure point occurs when the rescuer attempts to route the free-running end of the Velcro band through the second slit but leaves a loop of Velcro that gets caught in the buckle and won’t allow the band to tighten further, or when a person tries to feed a double loop through the buckle. (See Figure 6F and 6G.)

Both of these user-induced failures can be completely avoided by maintaining control of the buckle while applying the tourniquet by grasping the buckle on each side with the thumb and middle finger to prevent the buckle from rotating. (See Figure 6H.)

Additionally, if the band is pre-routed through a slit, using the index finger to lift slightly on the edge of the buckle enables you to easily pull adequate traction on the Velcro band and tighten it down sufficiently to activate the windlass rod successfully.

Grasping the buckle and using that piece as the point of counter-traction when tightening the band will prevent you from inadvertently grasping the windlass rod and creating slack in the tightening band. This technique also assists you in keeping the windlass rod positioned on the limb in a location where turning it doesn’t bind it into the axilla or groin.

Although our experience with the new GEN 7 is limited, we haven’t seen buckle rotation occur with the new design. However, holding the edges of the single slit buckle is still a good practice to keep the windlass rod well positioned and prevent inducing slack by pulling on the windlass rod while tightening the band.

Another user-induced point of failure we occasionally observe happens when the user applies a “death grip” on the Velcro band while routing it over the extremity. This causes the band to adhere to itself along the long (longitudinal) axis, which will often bind up when pulling it through the slit. (See Figure 6I.) We’ve observed this in training with both GEN 6 and GEN 7 CATs. It can be completely avoided by either not grasping the band in that manner, or by running a hand along the band just prior to tightening to relieve any misrouting issues

Figure 5: Common tourniquet tightening failures

SOFT-T CONSIDERATIONS

The SOFT-T (more specifically the SOFT-T Wide, which is the version we see in use most often) also has some unique characteristics that lend itself to user-induced ineffective application or failures.

Like the CAT, the most common errors in applications are failure to tighten the constricting band adequately prior to engaging the windlass rod, and using the windlass rod as an anchor point to tighten the band. The locking buckle on the SOFT-T Wide also has some unique characteristics that create user-induced failure points.

The most common user error we observe is failure to adequately tighten the band by pulling the band back against itself. When the slide-lock buckle is flat against the band and the user tries to pull the free-running strap tighter along the same plane, the locking bar engages and prevents the band from moving in either direction. This precludes additional tightening.

A helpful technique we teach is to have the user direct the strap upward and perpendicular to the buckle, and then use short, ratcheting motions to generate significant band tension.

Many users prefer to unclip the buckle, route the band around the extremity, then re-attach the buckle. We don’t recommend this approach because users can re-attach the buckle inverted. This makes it impossible to tighten the strap, and they must unclip the buckle and re-attach it.

Not only does this waste precious time, but it can inadvertently result in a twist in the band. This will create an exceptionally narrow area of pressure that may damage underlying tissues.

Users can also inadvertently put a twist in the strap by pulling a folded section of the strap through the buckle.

These band twists can be avoided by executing a simple finger sweep between the band and the extremity prior to completely tightening the band.

Figure 6: CAT buckle design

FINAL THOUGHTS

Applying a tourniquet to an extremity should be no more difficult in training or at a real incident than applying ECG leads or a blood pressure cuff properly. You must know, practice with and understand the fundamental nuances of the device you’re using, and train with it under realistic, scenario-based exercises.

In training, the only reason to not apply tourniquets just as you would in a real injury is if the simulated casualty tells you that a healthcare professional has told them not to allow a blood pressure cuff to be placed on that particular extremity. In addition, if you place a tourniquet on a simulated casualty’s leg during training, and that individual can walk easily, that tourniquet isn’t tight enough.

Avoid the potential user-induced errors we elaborated on. Reassess your interventions—particularly after every time you must move the casualty.

The bottom line at the end of the day is this: If you don’t train like you fight, you will fight the way you train, so train as if someone’s life depends upon it—because it probably will.

REFERENCES

1. Eastridge BJ, Mabry RL, Seguin P, et al. Death on the battlefield (2001–2011): Implications for the 1. Eastridge BJ, Mabry RL, Seguin P, et al. Death on the battlefield (2001–2011): Implications for the future of combat casualty care. J Trauma Acute Care Surg. 2012;73(6 Suppl 5):S431–S437.

2. Kotwal RS, Montgomery HR, Kotwal BM, et al. Eliminating preventable death on the battlefield. Arch Surg. 2011;146(12):1350–1358.

3. Kragh JF Jr, Walters TJ, Baer DG, et al. Survival with emergency tourniquet use to stop bleeding in major limb trauma. Ann Surg. 2009;249(1):1–7.

4. National Association of Emergency Medical Technicians. PHTLS: Prehospital Trauma Life Support. Jones & Bartlett Learning: Burlington, Mass., 2016.