The history of using tourniquets to treat severe bleeding from wounds dates back to at least the 1500s, where they were used to stop blood flow prior to amputations.
Today they are used to save limbs, and save lives, with recent changes to HSE guidelines suggesting their use as part of a standard first aid kit in certain circumstances. However, tourniquets haven’t always been recommended, and they fell out of common use after the experiences of the two world wars.
So what exactly is a tourniquet, how do they work, how and when should a tourniquet be used, and what training is required to use one?
What is a tourniquet?
A tourniquet is a tight band that is wrapped around an extremity, an arm or a leg, in order to stop the blood flow and prevent catastrophic blood loss. They apply pressure to both the arteries, carrying blood to the limb, and the veins carrying blood away, in much the same way as a blood pressure cuff.
A well-designed tourniquet should be easy to use, durable and able to apply enough pressure to stop arterial and venous blood flow without causing damage. The tourniquets found in first aid kits are designed for the maximum effect with the minimum damage, and some are even designed to enable victims to apply them to themselves when no assistance is available. The US military has even experimented with uniforms with tourniquets sewn in, ready for instant deployment in an emergency battlefield situation.
Are tourniquets required as standard in a first aid kit?
Since you are unlikely to encounter a traumatic blood loss injury in the average workplace, a tourniquet is not considered necessary for most first aid kits.
However the HSE June 2016 First Aid eBulletin recommended their inclusion if their use was indicated by a First Aid Needs Assessment. This includes high-risk industries such as construction, agriculture, forestry and some aspects of manufacturing, where the chances of sustaining a heavy bleeding injury are much higher. The HSE advice was based on the 2015 European Resuscitation Council review of first aid protocols. The UK Resuscitation Council approved the possible use of tourniquets as part of a first aid kit in October 2015.
If you require a tourniquet it is recommended you should have training in the use of them which can be included as part of first aid training.
When should a tourniquet be used?
As we will discuss below, there are risks and complications associated with tourniquets, and so they should only be used as a last resort when other measures are either not possible, due to the nature of the injury, or have failed to stop blood flow.
- First try to stop bleeding by applying pressure directly to the wound using a clean, lint free dressing. If the patient is conscious and able to help, they can apply pressure while you deal with other issues.
- Make sure the patient is lying down to reduce the risks from shock.
- Dress the wound and if bleeding appears through the dressing, place a second dressing over the wound.
- If bleeding appears through both dressings, remove them both and start afresh.
- If bleeding still persists, then, and only then, should you consider applying a tourniquet.
It is important to note the time that the tourniquet was applied, and to pass this information to the emergency services when they arrive.
Where should a tourniquet be placed?
Tourniquets need to be placed at least 5cm above the wound to be effective, as a severed artery can retract up into the limb. They should always be placed over a single bone, to make sure that all blood vessels are effectively blocked. If the injury is to the lower arm or lower leg, where vessels may be found in between two bones, then the tourniquet should be placed above the joint on the upper arm or the thigh.
The tourniquet needs to be pulled tight enough to fully stop the blood flow. A tourniquet will hurt, but that is no reason to loosen it. If it doesn’t hurt, chances are it is not tight enough. Once applied, the tourniquet should only be removed by qualified medical staff.
While a professional tourniquet from your first aid kit is always preferable, an improvised tourniquet may be used in an emergency. Stewart et al1, writing in the Journal of Trauma Acute Care Surgery, concluded that ‘in the absence of a commercially produced tourniquet, this simple first aid measure can satisfactorily arrest life-threatening haemorrhage’.
It is a common misconception, encouraged by Hollywood movies, that almost anything can be used as a tourniquet, but this is not the case. Narrow bands, such as ties or belts, carry a significant risk of nerve, muscle and tissue damage, and are not recommended. To prevent such damage, a tourniquet needs to be around 4cm wide. A folded triangular bandage makes a suitable improvised tourniquet.
Improvised tourniquets cannot simply be pulled tight and tied however. You should tie the tourniquet around the limb and then insert a stick, such as a pen or a piece of cutlery, to use as a windlass, twisting several times in order to achieve the correct pressure.
How tourniquets work
In the case of a traumatic injury to a major artery or vein, you can lose blood very quickly, as much as half of your blood supply in just a few minutes. This can lead to exsanguination and hypovolaemic shock, as the body struggles to pump what remains of your blood to the brain and other vital organs. Unless a transfusion is available, this can rapidly lead to death.
Tourniquets work simply and mechanically by stopping the blood flow to the ruptured or severed vessel. This prevents blood loss until the emergency services are able to take over and treat the wound.
How effective are tourniquets?
In a review of over three thousand cases of tourniquet use, by Beaucreux et al2, published in the journal Anaesthesia, Critical Care and Pain Medicine, found that the effectiveness of tourniquets ranged from 78% to 100%, and found tourniquet use to be ‘an effective tool for the management of extremity haemorrhages in civilian trauma’.
A further study, by the American College of Surgeons3 (available at www.ems.gov)aimed at developing guidelines for tourniquet use in pre-hospital settings, concluded that ‘tourniquets save lives’ and ‘the adverse side effects associated with tourniquets appear to be manageable and do not appear to outweigh the benefits of tourniquet use’.
Are there risks with tourniquet use?
The use of tourniquets can lead to complications if further treatment is not received promptly. In the world wars, victims often lost limbs due to lack of blood flow, as they were not seen by medics quickly enough and their tissues failed due to lack of oxygen. This is why tourniquets fell out of fashion. However, in modern use, emergency services are on the scene a lot quicker and this issue is not as relevant.
Today, the biggest risk with tourniquet use is improper placement of the tourniquet. If the tourniquet is not tight enough, then it may only cut off the venous blood flow, not the arterial flow. This is similar to the way that a blood pressure cuff is released to measure systolic pressure (in the arteries) and diastolic pressure (in the veins). This means that the stronger pressure arterial blood will still reach the limb and the wound, but will not have the pressure needed to return past the tourniquet. This can actually increase blood loss from the wound as pressure builds, creating the opposite effect to what was intended. Furthermore, trapped blood causes swelling of the limb and results in less blood available in the general circulation, increasing the risk of hypovolaemic shock.
Given the risks of incorrect tourniquet use, it is essential that all nominated first aiders are properly trained in tourniquet use, if they are provided as standard in their first aid kits.This will ensure that tourniquets are only used when appropriate, are positioned and tightened correctly and managed safely.
Tourniquet training, as part of a general first aid course, or as a separate additional course, can be very effective. The American College of Surgeons study, mentioned above, noted the importance of correct training in tourniquet use. In their conclusion they state that ‘proper training in tourniquet useis a key provision for making this intervention successful’.
Goralnick et al4, in their study Effectiveness of Instructional Interventions for Hemorrhage Control Readiness, published in May 2018, found that ‘in-person haemorrhage control training for laypersons is currently the most efficacious means of enabling bystanders to act to control haemorrhage’. The study found that in-person training was much more effective than either flash cards or audio instructions provided at the time of the incident. However, they did find that retention of the skills dropped off rapidly after 3 to 9 months, indicating that refresher training is also needed to maintain skill levels.
Despite their proven effectiveness, a significant number of businesses still do not carry tourniquets in their standard first aid kits, even when they operate in high risk industries where there is a significant chance of sustaining a traumatic vascular injury. The HSE guidelines encourage such companies to review their first aid provision, providing tourniquets as standard and offering tourniquet training for all appropriate staff.
- Stewart SK, Duchesne JC, Khan MA Improvised Tourniquets: obsolete or obligatory: Journal of Trauma Acute Care Surg
- CharlotteBeaucreux,BenoîtVivien, EthanMiles, SylvainAussete, PierrePasquierApplication of tourniquet in civilian trauma: Systematic review of the literature. Anaesthesia Critical Care & Pain MedicineJan 2018
- Snyder D, Tsou A, Schoelles K. Efficacy of Prehospital Application of Tourniquets and Hemostatic Dressings to Control Traumatic External Hemorrhage. DOT HS 811 999b. Washington, DC: National Highway Traffic Safety Administration. May 2014.
- Eric Goralnick, MD, Muhammad A. Chaudhary, Justin C. McCarty, et al Effectiveness of Instructional Interventions for Hemorrhage Control Readiness for Laypersons in the Public Access and Tourniquet Training Study (PATTS)A Randomized Clinical Trial. JAMA Surg. Published online May 2018.