tourniquet

a device used to arrest bleeding, usually from an ARTERY in a limb, which may be a length of bandage, rubber tube or cord tied tightly around the limb, generally as an emergency measure. Direct pressure on a WOUND is now considered to be preferable as a first aid measure, because a tourniquet can deprive all the tissues of oxygen by arresting the CIRCULATION and there is a risk of damage and of GANGRENE .