Tourniquet

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For other uses, see Tourniquet (disambiguation).

Two tourniquets of different fabrication, these are used for venipuncture

A tourniquet is a tightly tied band applied around a body part (an arm or a leg) sometimes used in an attempt to stop severe traumatic bleeding, but also during venipuncture, and other medical procedures. Severe bleeding means the loss of more than 1,000 ml (1 litre) of blood. This flow of blood can soak a paper or cloth handkerchief in a few seconds. In such a situation, the bleeding will cause the death of the casualty in seconds to minutes.

A tourniquet is a last resort method of bleeding control. Other methods that should be applied first and in conjunction, if possible, include:

direct pressure
elevation of the limb or wound above the heart
the use of a pressure point to slow the artery above the injury(s)
blood-clotting agents or bandages

Even in cases of amputation, most bleeding can be controlled through these alternative methods. The rare exception is when a limb is shattered by massive trauma or when a major blood vessel is torn along its length. Even in these cases, the use of a pressure point above the wound (i.e. proximal to the wound), or application by a doctor of an hemostat, to clamp the blood vessel above the tear is strongly preferred.

The use of tourniquets is taught to emergency medical technicians including combat lifesavers, and as a part of military first aid in basic training. It is also part of the French basic first aid courses (for bystanders).

Tourniquets are also used during some orthopedic surgeries to allow the surgeon to work in a bloodless field. When used this way the duration of application and pressure of the tourniquet are carefully monitored. Under these well controlled conditions complications from the tourniquet are rare.

1 Risks of a tourniquet
2 When to use a tourniquet
3 Once a tourniquet is applied
4 See also
5 External links

[edit] Risks of a tourniquet

As the tourniquet stops the perfusion of the limb, the resulting anoxia can cause the death of the limb, forcing the later surgical amputation of the limb just below the level the tourniquet is applied. This is likely to occur when the tourniquet stays in place several hours. In any event, once a tourniquet has been applied, advanced medical care from a doctor or hospital will be required to salvage the limb if not save the life of the patient.

The status of the tourniquet varies widely according to the country. This situation can be illustrated by the opposite philosophies applied in the United States and in France.

In any case, the first aider/rescue should act according to the local conditions (laws, rescue organisation and philosophy).

[edit] United States (civilian)

The decision to employ a tourniquet should be made by an emergency medical technician or preferably a doctor if at all possible. But when severe external bleeding cannot be controlled by other means, a tourniquet may be the only way for a first-aider to save the casualty. (A medical professional might use a hemostat or resort to field surgery.)

Most civilian first aid instruction in the United States no longer teaches the use of the tourniquet for the following reasons:

the effectiveness of direct pressure, elevation and pressure points (controlling severe bleeding in up to 90% of cases as estimated by US medical sources)
the increased difficulty of reattaching an amputated limb when a tourniquet has been applied to the victim
unnecessary use by poorly trained bystanders
the unavoidable risks to both limb and life even when properly employed
the rare nature of injuries that require tourniquets, which typically occur in unusual settings such as working with agricultural or industrial machinery and the battlefield

The use of a tourniquet by a layperson in countries where it is considered outside the scope of practice of first aid may result in civil lawsuits and/or criminal charges, especially if the application was later found to have been unnecessary.

[edit] United States military

Battlefield experience in Iraq has caused the US military to reconsider the 'conventional wisdom' regarding tourniquets. Life threatening bleeding from extremities is more common because body armor protects the torso. Blast injuries to limbs rarely result in a clean amputation or a salvageable limb, and a rapidly applied tourniquet can be immediately lifesaving when arterial (spurting red) bleeding results from such major injuries.

The US Military has also found (through experience in Iraq) that due to the ability to transport a casualty to a surgeon in less than an hour of being wounded, tourniquets are used far more frequently for injuries from gunshot wounds to amputations. Formerly, tourniquets were not used as much, due to the difficulty of transporting the casualty to a skilled physician in time to save the limb.

All US Army soldiers and US Marines are now required to carry a tourniquet as part of their individual first aid kits. First aid training for soldiers now addresses the "prompt and decisive" use of tourniquets to control life-threatening extremity bleeding.

[edit] In France

In France, the tourniquet is taught to the general public, in the first level of first aid course (Attestation de formation aux premiers secours, 10 hours without any prerequisite). The French emergency medical service (Samu) considers that the rhabdomyolysis (destruction of the muscle cells due to the anoxia) is not likely to endanger the limb before six hours, i.e. the casualty receives advanced medical cares by a physician (either a medical prehospital team or at the emergency room of a hospital) long before the risk occurs.

The act is thus considered as proportional to the risk (death by blood loss), and the first aider/rescuer is not likely to be condemned in case the limb is lost (although the legal risk is not totally absent): this loss would be attributed to the wound and not to the saving act. Especially, the tourniquet is considered as an alternative to avoid infection by contact with the blood of the casualty when the first aider has no protecting device (e.g. plastic bag, piece of cloth etc.).

If it is not removed within six hours of being first placed on the injured limb, amputation may be required.

[edit] In Australia

In Australia, people undergoing a first aid course will be instructed to never use a tourniquet. They are further instructed that if you have a first aid certificate there can be legal issues with using a tourniquet.

[edit] When to use a tourniquet

A tourniquet should be applied only when other methods were tried and failed to stop life-threatening bleeding.

A tourniquet could be used if a single first-aider is holding a pressure point and is forced by exigent circumstances to abandon the casualty to save lives (for example, to call for help or perform triage). However, this practice is not sanctioned in some countries, including the United States.

Tourniquets are not used to treat snakebite; a constrictive band intended to slow the spread of poison through the lymphatic system in a snakebite victim should be fairly loose compared to a tourniquet.

[edit] Once a tourniquet is applied

In some countries, first aid training states: Never loosen a tourniquet in the field - while the tourniquet maintains the blood in the rest of the body, the limb is poorly oxygenated (anoxia), so the muscles controlling the blood vessels are relaxed (vasodilatation). If the tourniquet is released, the blood will flow through these wide opened vessels; the blood pressure will drop, causing a hypovolemic shock, or worse making the cardiac pumping inefficient.

Additionally, after several minutes, toxins will begin to build up in the dead tissue below the tourniquet (rhabdomyolysis). These toxins can swiftly kill if introduced into the body's bloodstream.

In wilderness first aid, it is imperative that any person with a tourniquet be evacuated to advanced medical care as soon as reasonably possible. Immediate MEDEVAC is indicated if the limb is to be salvaged. If the limb is lost, MEDEVAC is indicated if transport will be delayed more than twenty-four hours.

In triage, a person with a tourniquet should be considered "I" for immediate in the START protocol and at least "Yellow" or higher in other protocols.