4 Common Types of Tourniquet Explained
There are several different types of tourniquets that limit or stop blood flow to and from a person's extremities (arms and legs) in the case of severe bleeding, surgery, and blood draws. When choosing a tourniquet cuff or band to add to your first-aid supplies, it's important to understand the different types of tourniquets that exist, what each has to offer, and how to choose.
Types of Tourniquet by Intended Use
The most common types of tourniquets are emergency tourniquets (which themselves can be divided into several subcategories), surgical tourniquets, rehabilitation tourniquets, and clinical tourniquets.
1. Emergency Tourniquets
Emergency tourniquets are used to stop arterial blood flow completely to limit limb bleeding that cannot be controlled by applying direct pressure alone. Perfected in military applications, emergency tourniquets are included in all trauma kits and can be especially useful in the case of:
- Gunshot wounds
- Household accidents, especially those involving sheet glass
- Farm and industrial accidents
- Crushed limb injuries
Emergency tourniquets should not be left on for longer than two hours as longer application times could lead to nerve injury and limb loss. However, that shouldn’t scare you away from using them. As a temporary measure, a tourniquet can stem traumatic bleeding until the injured person can be transported to a hospital for treatment. Furthermore, a tourniquet even has the potential to save a crushed limb if it’s applied in time.
To be effective, all emergency tourniquets need to have a locking mechanism that maintains the necessary pressure to stop blood flow to the extremity. The main mechanisms used today are the windlass, ratchet buckle, dial, pneumatic hand pump, and wide stretch band.
Windlass tourniquets use a small stick that is turned to tighten a band until arterial occlusion is reached. This means that arterial blood flow ceases on the other side of the tourniquet and there is no longer a distal pulse (which is a pulse that’s further away from the heart, on the far side of the tourniquet). The word tourniquet itself comes from the French word tourner, which means "to turn."
Most improvised tourniquets made from materials like stretchy cloth use a windlass tightening mechanism—usually a pencil, pen, stick, or similar—to reach limb occlusion pressure (LOP). The risk, however, is that the object used for a windlass could break, leading to rebleeding and possible death. The material used as a band (sometimes a cord or a tie) can also cause skin and tissue damage if it's too thin or too hard.
Commercial windlass tourniquets, in contrast, are made from extremely strong and durable materials that won't break, come loose, or cause any unnecessary damage to the tissues or skin. There are several heavy-duty windlass-style commercial tourniquets on the market today.
Combat Application tourniquet (CAT)
The Combat Application tourniquet (CAT) was one of the first commercial tourniquets to be released and has proven its effectiveness in the U.S. Military. This tourniquet consists of a strap that comes apart for fitting around the limb and a strong plastic windlass. The strap is looped differently through the buckle depending on whether it's placed around an arm or a leg. After tightening the strap to occlusion pressure, the windlass is secured with Velcro.
Tip: As this tourniquet has been around for a long time, early issues with the CAT have been fixed and the general design improved. So if you purchase this tourniquet, make sure you get the latest version (Gen 7 at the time of writing).
The SAM-XT is a more recent windlass-style tourniquet that was designed for rapid application and is recommended by the U.S. Department of Defense’s Committee on Tactical Combat Casualty Care (CoTCCC). With this tourniquet, fewer windlass turns are required to reach limb occlusion pressure, and TRUFORCE™ Buckle technology locks by itself when a predetermined amount of circumferential force is reached. As eliminating all of the slack is the key to stopping arterial bleeding, this tourniquet makes it easy for even the lay rescuer or injured person to stop the bleeding in three simple steps: click, twist, and secure.
Military Emergency Tourniquet (MET)
The Military Emergency Tourniquet (MET) is an open-loop tourniquet with a strong strap and an aluminum windlass. This tourniquet comes apart for fitting around an extremity and can be tightened entirely by turning the windlass. Once tightened, the windlass is secured in two places: one adjustable and one with Velcro. The third generation of the MET has a wider strap than the first two generations, which is important as wider straps come with a lower likelihood of damaging the skin, muscles, and nerves.
Emergency Tourniquets with Alternative Mechanisms
Ratcheting Medical Tourniquet (Gen 3)
The Ratcheting Medical Tourniquet is a closed-loop tourniquet with a wide strap that can be opened to fit around a limb. The strap is then looped through a metal ring and pulled tight before activating the ratcheting buckle. After applying pressure, the ratcheting buckle locks automatically to keep the tourniquet tight. Once the injured person is being treated and no longer needs the tourniquet, the device can be removed easily by pressing the in-built release inside the buckle.
Dial-Tightened Tourniquet: Mechanical Advantage Tourniquet (MAT)
The Mechanical Advantage Tourniquet consists of a preformed plastic "C" shape that is designed specifically for an arm or a leg (this tourniquet comes in two sizes). To apply this closed-loop tourniquet, simply secure the strap onto the hook and turn the dial to draw in the cord inside the strap until limb occlusion pressure is reached. To remove the tourniquet, you can lift the plastic hook with which the strap is secured or press the release button on the side.
Pneumatic Tourniquet: Emergency Medical Tourniquet Cuff (EMT)
The Emergency Medical Tourniquet cuff is designed like a blood pressure cuff with a hand pump that increases pressure until arterial bleeding stops. However, unlike a blood pressure cuff, this device has a reinforced pneumatic bladder to prevent air loss during and after inflation and hold the open-loop strap tight. The advantage of this tourniquet is its consistently high effectiveness rating. However, it is larger, heavier, and more expensive than windlass tourniquets.
Stretch Band Tourniquets: SWAT-T
The SWAT-T and other similar band devices represent the simplest and most intuitive kind of prehospital tourniquet. To use these tourniquets, simply stretch the band, wrap it around the extremity (above the wound), and tuck in the end to hold the tourniquet tight.
Of all the different types of tourniquets, this requires the least training and is the most versatile because of its simple construction. It can be used even on the narrow limbs of children and pets. The main trick when using a stretch-band tourniquet is to make sure it's wrapped tightly enough that there's no distal pulse.
2. Surgical Tourniquets
Surgical tourniquets are similar to emergency tourniquets in that they prevent blood flow to a limb—except that in this case, it’s so that surgeons can perform certain orthopedic and plastic surgery procedures without blood getting in the way. Pneumatic and non-pneumatic tourniquets are used in surgery, with pneumatic tourniquets often being preferred thanks to the possibility of measuring the patient’s systolic blood pressure and controlling the circumferential pressure with great precision.
3. Rehabilitation Tourniquets
Like emergency and surgical tourniquets, rehabilitation tourniquets restrict arterial blood flow. However, rather than stopping arterial blood flow completely, rehabilitation tourniquets merely restrict it temporarily to help a patient increase muscle size and strength faster when performing low-intensity exercises.
4. Clinical Tourniquets
Clinical tourniquets are the simplest and lightest of all the different types of tourniquets. They consist of a simple elastic band that is tightened to pronounce the veins for needle insertion and blood draws. In contrast to emergency tourniquets, clinical tourniquets are extremely low-tension and will not stop bleeding in an emergency.
Finding the Right Type of Tourniquet for You
If your aim is to save a life in the context of traumatic bleeding, the best tourniquet will be one that's designed for emergency use—whether it's secured with a windlass, ratchet, dial, or pneumatic inflation. When choosing a tourniquet kit, keep in mind your experience and training level, the most likely application (adult, pediatric, or canine), and any features that you find especially valuable.
As soon as you buy the device, make sure you go for training in first aid and bleeding control procedures so that you feel confident to perform a tourniquet application in an emergency. It's recommended to refresh your tourniquet training every three months to keep your skills and knowledge sharp. As these are small, cost-effective devices, you can't go wrong when purchasing a tourniquet. As long as it's designed to stop arterial blood flow, that tourniquet could save someone's life.