Arterial tourniquets should only be used for life-threatening bleeding from a limb, where the bleeding cannot be controlled by direct pressure. Ideally, a tourniquet should not be applied over a joint or wound and must not be covered up by any bandage or clothing.

Commercially manufactured windlass tourniquets such as those based on military designs are more effective than improvised tourniquets1. An example of a military tourniquet is shown in Fig 1 below. Effective use of commercial tourniquets is optimal when first aid providers are trained in proper application techniques.

All arterial tourniquets should be applied in accordance with the manufacturer’s instructions (or 5 cm above the bleeding point if no instructions) and tightened until the bleeding stops.

If a tourniquet does not stop the bleeding its position and application must be checked. Ideally the tourniquet is not applied over clothing nor wetsuits and is applied tightly, even if this causes local discomfort.

If bleeding continues, a second tourniquet (if available) should be applied to the limb, preferably above the first.

If a correctly applied tourniquet(s) has failed to control the bleeding, consider using a haemostatic dressing in conjunction with the tourniquet.

An elastic venous tourniquet (designed to assist drawing blood samples or inserting intravenous cannula) is not suitable for use as an arterial tourniquet.

Improvised tourniquets are unlikely to stop all circulation to the injured limb without risk of tissue damage. Improvised tourniquets which do not stop all circulation can increase bleeding. Nonetheless, in the context of life-threatening bleeding, an improvised tourniquet is likely to be better than no tourniquet. Tourniquets, ideally of a similar broad width to commercial types, can be improvised using materials from a first aid kit (e.g., triangular bandage, elastic bandage) from clothing, a surfboard leg rope or other available similar items. Improvised tourniquets should be tightened by twisting a rod or stick under the improvised tourniquet band, similar to the windlass in commercial tourniquets.

The time of tourniquet application must be noted and communicated to emergency/paramedic personnel. Once applied, the person requires urgent transfer to hospital and the tourniquet should not be removed until the person receives specialist care.