Ratchet Tourniquets?

         I recently cited to an article entitled "Twist the Stick: It’s not a tourniquet without a windlass" by Mike Shertz at the Crises Medicine blog. The gist of the article was that to stop arterial bleeding from arteries deeper in a limb and with higher blood pressure, you needed to use a type of tourniquet that uses a windlass. Shertz specifically noted that "[s]imply tying a constricting band tightly around a limb rarely provides enough pressure to occlude arterial flow.  To stop bleeding requires a mechanical advantage, and to obtain that advantage you need a windlass or twist stick to tighten the constricting material." As another author (and former medic) relates:

A venous tourniquet, meaning a tourniquet applied tight enough to stop all venous blood return to the core, but still allow arterial blood into the limb (and out the wound) can very easily kill a casualty.  And if it doesn’t kill them, I believe this is where the dogma of ‘tourniquet on a limb means you lose the limb’ came from, it can create a compartment syndrome and speed tissue necrosis much faster than a properly tightened tourniquet.

But what type of tourniquet? A long time reader recently passed on to me information about tourniquets, including references to ratcheting styles of tourniquets. These are tourniquets that have a ratcheting mechanism and ratcheting belt attached to the tourniquet. One model of this type is the Revmedx TX2, which you can see being demonstrated in this 2 minute video.

      It looks like a neat idea, but not one with which I was familiar. Not being an expert on tourniquets, I decided to look to some other sources about tourniquets generally and to see if I could find information on the ratcheting style.

       Greg Ellifritz has written about tourniquets at different times, most recently in his October 1, 2018, article, "The Tourniquet that 'Works Like a Zip Tie'." In that article, he makes some general observations on tourniquets, including pointing out that tourniquets that do not use a windlass type system have traditionally done poorly in military trials. He also suggests that you should use a tourniquet that has been approved by the Committee on Tactical Combat Casualty Care (COTCCC). And he raises some important points that need to be addressed as to an effective tourniquet, especially one that may be applied in a tactical environment or a disaster where help is not a quick ambulance ride away. His bottom line is that only the CAT and the SOFT-T Wide tourniquets have been approved by the COTCCC. A friend of Ellifritz, Jonathan Willis, had also penned a guest post in 2014 recommending the CAT, foremost, and then the SOFT-T Wide. (See also, "Not all Tourniquets are Created Equal").

      In looking around for other reviews of ratchet style tourniquets, I came across an article at The Prepared blog discussing the best tourniquets. No surprise, the best ones were the CAT and the SOFT-T (with a warning about buying cheap imitations). But the article also briefly looked at competitors and other types of tourniquets. Mirroring the articles I note above, the authors pointed out:

Tourniquets that don’t use a windlass are at a mechanical disadvantage. It can be a lot harder for an average person to create enough pressure around a large meaty leg just by wrapping and tucking stretchy rubber. The windlass is what gives you leverage, like lifting something heavy with a pulley or folding a garden hose in half instead of pinching the tube with your fingers.

 And they had this to say about the ratcheting style:

There are some ratchet styles floating around, but we don’t recommend them. Army Rangers tested them in the field in the 2000s and went back to the windlass style. There are too many points of failure, such as clothing/skin/blood getting stuck in the ratcheting mechanism.

      So, in short, the COTCCC has approved three limb tourniquets for use: the CAT, the SOFT-T and the EMT (Emergency Medical Tourniquet), but the latter is a pneumatic tourniquet which is bulky and expensive and unsuited for an individual first-aid kit. A July 2017 article in Medical Medicine identified the Alphapointe Tactical Mechanical Tourniquet (TMT) as a possible option, noting that it was better than the CAT for controlling bleeding when placed around the mid-thigh (you may need two CATs side-by-side for that task). But it is not (at least, not yet) on COTCCC's approved list. Note that the CAT is in its 7th generation, which apparently addressed some deficiencies in earlier models when self-applied (large PDF).  And that appears to be where the current state-of-the-art is as to tourniquets.