Recently while browsing the web I landed across several rather confusing statements about tourniquets. Apparently, there are actually people out there are people who don’t believe in them or are advocating for ridiculous ways of applying them. If you are someone who doesn’t believe in tourniquets or just are not sure why you should have one, head over to our other post on why everyone should have a tourniquet. Here are two of the most common myths I’ve seen that need to be dispelled.
The Two Bone Compartment Myth
Anyone with rudimentary human anatomy training knows that the distal portions of both upper and lower limbs have two bones supporting form and function. In the arms, it is the radius and ulna. In the legs, it’s the tibia and fibula. They have evolved like this to allow bipedal movement and digital dexterity. While it is true that the vasculature of these distal areas are deeper; vasculature evolved this way to protect the distal limbs from catastrophic hemorrhage. This does not mean tourniquets are less effective on them. In fact, that above comment couldn’t be further from the truth.
The Two Bone Compartment Myth is Non- Sequitur logic fallacy; assuming ‘this’ follows ‘that’ with no actual factual connection. Effective tourniquet application relies on sufficient tissue compression to occlude all blood flow, both venous and arterial. Bones are well-nigh incompressible without causing a fracture. But, the tissue around them is very compressible. ‘This’ does not follow ‘that’.
In 2008, over a decade ago, Kragh et al. published a paper in the Journal of Trauma called ‘Practical Use of Emergency Tourniquets to Stop Bleeding in Major Limb Trauma’. This paper discusses, among other things, the efficacy of tourniquets based on limb regions. Proper application of tourniquets on the distal portions of limbs was found to be MORE effective.1 Forearm application was 92% effective compared to upper arm application at 81%.2 This was even more dramatic in thigh versus lower leg application! Thigh application was found to be 73% effective compared to 100% effectiveness on lower leg applications!3 Even in self-application, thigh applications were found to be less effective; while lower leg and forearm were self-application were very effective.4 The study went on further to state ‘device width relative to limb girth was the commonest reason for tourniquet ineffectiveness’.5
“Tourniquets work well proximal to the wound even on the forearm or leg and need not be on the thigh or arm as sometimes recommended.”
Kragh et al., J Trauma, Feb. 2008
High and Tight Dogma
So, if limb circumference adversely affects tourniquet effectiveness, where does ‘High and Tight’ come from? Why does it recommend tourniquet application in less effective positions? First, for clarity, the concept of ‘High and Tight’ in tourniquet usage means to place it as proximal as possible on the injured limb. Simply, without assessment, apply the tourniquet as high as you can on the arm or thigh regardless of the position of the wound. This concept has some merit during Care Under Fire (CuF) in very specific circumstances.
The current Committee of Tactical Combat Casualty Care (CoTCCC) guidelines states in the Basic Management Plan for Care Under Fire: “Apply the tourniquet over the uniform clearly proximal to the bleeding site(s). If the site of the life-threatening bleeding is not readily apparent, place the tourniquet ‘high and tight’ (as proximal as possible) on the injured limb and move the casualty to cover. Ensure that the slack is removed prior to cranking the windlass.”6 So, if there is high velocity metal flying around you AND you can’t visualize the bleed, go ‘High and Tight’ then get to cover. If there is a direct threat and you can visualize the bleed, apply the tourniquet above the wound and get to cover. Interventions based on the threat and current environment. This is the forte of tactical medicine.
Tactical Field Care (TFC) is casualty care applied when there is no direct threat but an indirect threat still exists. Tactical Evacuation Care (TEC) is the casualty care given during either a CASEVAC or MEDEVAC. During TFC & TEC, the CoTCCC recommends to: “Assess for unrecognized hemorrhage and control all sources of bleeding. If not already done, use a CoTCCC recommended limb tourniquet to control life-threatening external hemorrhage that is anatomically amenable to tourniquet use or for any traumatic amputation. Apply directly to the skin 2-3 inches above the bleeding site; apply a second tourniquet side-by side with the first.”7 Basically, when no direct threat to the casualty or responder exists, assess the casualty and intervene using best practices to ensure a positive outcome!
The problem is layman teaching tactical medicine! ‘High and Tight’ is the ‘Scan and Breath’ of tactical medicine. People preach it religiously and don’t know why, when or understand the dangers of dogma in medicine. ‘High and Tight’ is easy to teach in a 2 day tactical medicine course. It is a chant that can be recited as a liturgy that seems successful in dry training. However, with the reduced efficacy of tourniquets on areas of limb with greater circumference, this will not be true in a real world situation. Skipping the necessary instruction to develop proper casualty assessment skills in favour of a sexy mantra is not doing casualties or responders any favours and creates a misleading sense of effectiveness. Tactical Medicine is still medicine and must follow the science and best practice. Beware the instructor or internet expert preaching the ‘High and Tight’ dogma or rationalizing the ‘Two Bone Compartment Myth’. The science does not support their suppositions and science doesn’t care about your opinion.
Ben