How to Apply a Tourniquet

How to Apply a Tourniquet
25 January 2023

How to Apply a Tourniquet

A tourniquet can be used to save their life in a life-threatening situation where a casualty suffers wound trauma and heavy bleeding. A tourniquet is used to stop blood flow to a vein or artery. Where injuries are extensive, and it’s not possible to stop blood flowing out of a wound with pressure or a wound dressing, a tourniquet could be the only option. 

Tourniquets are generally only used by first responders and trained professionals who must provide critical first aid before a casualty gets to a hospital. They can also be used during surgery to keep the patient safe and prevent heavy blood loss.

There are times when untrained people might also need to use a tourniquet. If you find yourself in a car accident, you might be the only person who can help a casualty with heavy blood loss when seconds count. In this article, we’ll teach you how to use a tourniquet so you’ll be prepared at the vital moment and know how to improvise and make one from scratch.

Teenage girl wearing face mask, nurse applying medical tourniquet

Find out more about tourniquets in our article What is a Tourniquet? Everything You Need to Know.

How to Tourniquet a Wound

The original and most common style of tourniquet employs a simple method. A band is placed around the limb with a knot or similar hole through with a rigid rod or windlass can be placed. The action of tightening the tourniquet is achieved by twisting the windlass, which winds the band up, leveraging more and more pressure on the limb until it cuts off the flow of blood. 

Modern first aid has given us some different tourniquets too, and we sell a wide range of varying tourniquet products at Steroplast. Let’s look at how each type works.

How to Prep a Tourniquet: Things to Think About Before You Start

Before using a tourniquet, there are some precautionary measures and considerations to keep you and the casualty safe and minimise the risk of misusing the tourniquet. 

  • Make sure the casualty is in a safe place away from hazards while you work.
  • Put on disposable gloves if you can. Wash your hands before and after applying the tourniquet. If you’re in a remote location, many first aid kits contain sterile wipes you can use to clean your hands.
  • Some tourniquets require two people to use them. Make sure you have someone nearby to help if you can.
  • Can you try to use another bleed control method, such as a haemostatic dressing? A tourniquet should be treated as a last-resort measure.
  • Do you have a pen to write the time on the tourniquet when it’s applied? Consider writing the time immediately before starting if you’re using a pen as a windlass in a makeshift tourniquet.

Applying a CAT (Combat Application Tourniquet)

The CAT is the most commonly used tourniquet in the world and an intelligently designed adaptation of the first tourniquet, including the windlass rod and strap. This tourniquet works by twisting the strap around the windlass to increase pressure and cut off blood to the limb.

  1. Expose the skin where the wound is, if possible, by pulling clothes up or cutting them away.
  2. Pull the end of the strap completely out of the buckle if you apply a tourniquet with two hands. If you are using it one-handed, loosen the strap to create a hole large enough for the limb but do not pull the strap out of the buckle.
  3. Position the CAT roughly 3 inches above the wound. If two-handed, wrap the strap around the limb, then feed the end of the strap through the slit of the buckle. If one-handed, feed the limb into the loop you created in step 2.
  4. Pull the strap tight around the limb and fasten it back on itself but not over the windlass and clip. The band should be so tight that you cannot pass your fingertips underneath it. If you can, you should refasten it. 
  5. Twist the windlass to tighten the CAT. Once the bleeding has stopped, secure the windlass in the clip. 
  6. Check the wound to make sure it is no longer bleeding. You should also check for a distal pulse. If either is found, tighten the CAT some more using the windlass.
  7. Secure the windlass and clip with the time strap, and write the time on the time strap.

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Applying a SOF-T (Special Operations Forces Tactical) Tourniquet

A SOF-T tourniquet is similar to a CAT in function. It uses the windlass twisting method to tighten. The SOF-T tourniquet uses a buckle mechanism to tighten instead of velcro, and this is one reason some people prefer the SOF-T over the CAT, as it eliminates a step.

  1. Move clothing if possible to allow the tourniquet to make direct contact with the skin.
  2. Loosen the SOF-T tourniquet and feed it over the limb, placing it roughly 3 inches above the wound.
  3. Pull the strap to tighten the tourniquet. It should be so tight you cannot fit your fingertips underneath. 
  4. Once tight enough, twist the windlass until the wound stops bleeding.
  5. Secure the windlass in the clip and lift the triangular buckle over the end of the windlass to lock it in place.
  6. Check the wound for signs it is still bleeding. Check for a distal pulse. If either is found, tighten the tourniquet using the windlass some more.
  7. Write the time on the end of the tourniquet strap. 

Watch emergency medical technician Scott demonstrate how to apply a SOF-T tourniquet, or watch our TikTok video.

Applying a S.T.A.T (Smart Tactical Application Tourniquet)

A S.T.A.T. is known for being one of the easiest tourniquet types to use, making it good for civilian use. It also incorporates a timer, so there’s no need to write the time down. You just need to press a button. However, this tourniquet does rely more on the force applied, so it requires more strength to tighten it.

  1. Expose the skin around the wound to apply the tourniquet directly, if you can.
  2. Place the opened tourniquet around the limb, positioning it around 3 inches above the wound. 
  3. Pass the end of the tourniquet through the locking buckle.
  4. Holding the tourniquet in place, pull the strap tight.
  5. Bring the end of the strap around and feed it through the top of the buckle.
  6. Start the one-hour timer by pressing the button.

Watch emergency medical technician Scott demonstrate how to use a S.T.A.T., or take a look at our TikTok video.

Applying a SWAT (Stretch, Wrap, and Tuck) Tourniquet

A SWAT tourniquet is another simple-to-use device. Instructions are printed on the device, including optimal cues to show whether you’re applying enough pressure. A SWAT tourniquet can also be applied higher up in the groin or armpit than other types. It can also be applied to smaller limbs like those of children and service animals. That said, a SWAT tourniquet is another type that requires the applier to use high levels of force rather than the windless twisting mechanism.

  1. Expose the skin around the wound so you can make direct contact with the tourniquet. 
  2. Unwrapping one end of the tourniquet, hold it against the body about 3 inches above the wound. 
  3. Wrap the tourniquet around the limb once and over the end.
  4. Once this first layer has been secured, stretch the tourniquet until the diamond shapes on the tourniquet become squares. This is how you know you are applying enough tension.
  5. When the tourniquet has been fully wrapped around the limb, hold up the edge of the last loop and tuck the end of the tourniquet under it.
  6. Check the wound to ensure it has stopped bleeding, and check for a distal pulse. Tighten the tourniquet if either is present. 
  7. Write the time clearly on the tourniquet.

If you find you cannot stop the bleeding after tightening a tourniquet again, apply a second one above the first. 

Always leave a tourniquet visible on a casualty, so paramedics know it’s there as soon as they arrive. The casualty may be unconscious, and you might not be there to tell them.

How tight should a tourniquet be?

If a tourniquet is too loose, it simply won’t be effective. A tourniquet must be tight enough to stop the distal pulse in the area it covers completely. If a tourniquet is not tight enough, the casualty will continue to bleed out through the wound. Bleed could be slower but more difficult to notice and the casualty could be in danger without anyone knowing. 

A too-loose tourniquet is also a danger because in not obstructing arterial in-flow, it will more than likely obstruct venous out-flow. This could result in compartment syndrome and lead to muscle and nerve damage.

Take care to check the wound has stopped bleeding completely before finishing your tourniquet.

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How to Make a Tourniquet from Scratch

Tourniquets are not generally included in first aid kits; professionals will have access to tourniquets in first responder kits and emergency vehicles. So, if you suddenly need to apply a tourniquet, you’ll need to know how to do it and what to use. 

You can easily make a tourniquet from a triangle bandage (something commonly found in all first aid kits) and a pen. Here’s how to create a tourniquet.

  1. Fold the triangle bandage into a long thin section. 
  2. Wrap the tourniquet around the limb two or three inches above the wound. 
  3. Tie the triangle bandage in a simple knot and tie it as tight as you can. 
  4. Lay the pen over the knot and tie a second knot holding the pen in place.
  5. Tighten the tourniquet by twisting the pen. Continue to tighten it until the wound stops bleeding.
  6. Wrap the ends of the bandage around both ends of the pen, then bring one end of the bandage underneath and tie them both together to hold it in place.

Write the time on the bandage, so paramedics know when it was applied.

Watch our TikTok video demonstrating how to make a homemade tourniquet using this technique.

Many people wonder how to make a tourniquet with a belt, thinking this would be an ideal item to use as a makeshift tourniquet. But this isn’t actually correct. The action of twisting the windlass in a tourniquet gives someone the force needed to make the device effective. Using a belt around a limb and tightening it the same way you would around your waist will never produce the amount of force needed to stop blood flow, even if you are very strong.

How long should a tourniquet be left on?

How long can a tourniquet be left on? Many people think putting a tourniquet on a limb means it will need to be amputated because cutting off the blood supply will do irreversible damage, but this isn’t necessarily true. A tourniquet is designed to protect the casualty from exsanguination by stopping bloodflow to a limb, but as long as it’s only on for a certain amount of time, the whole limb has the chance to recover. 

A tourniquet should be kept on only for as long as it takes to get the casualty to a hospital or a place where they can receive medical attention. Generally, if a tourniquet is in place for two hours or less, the limb should be able to recover (excluding the recovery associated with the injury that necessitated the tourniquet). At the four to six hour mark, a tourniquet can result in complications for the limb.

This is why it’s so important to record the time the tourniquet was put on so that paramedics know how quickly they need to work to remove it and treat the casualty. Some tourniquets, like the S.T.A.T. Trainer Tourniquet and the S.T.A.T. Orange Tourniquet, have a timer you can activate by pushing a button. Others will have a space where you can write the time directly onto it.

STAT Tourniquet timer

How often should you release a tourniquet?

How often do you release a tourniquet? Unless you’re a trained professional and prepared to surgically control the haemorrhage, the tourniquet must stay fastened on the limb without being loosened.

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