A tourniquet halts severe, life-threatening bleeding from a limb. It works by applying pressure to restrict blood flow. Proper application is important for effectiveness and patient safety.
The Principle of Placement
Correct placement is fundamental for effective bleeding control. The general rule is to place the tourniquet 2 to 3 inches (5 to 7.6 centimeters) above the wound, between the injury and the heart. This aims to compress the main artery against the limb’s single bone, which is why tourniquets are used on the upper arm or upper thigh. Avoid placement directly over a joint (e.g., elbow or knee), as joints protect blood vessels, preventing necessary compression and potentially causing nerve or blood vessel injury.
For optimal function, apply a tourniquet directly to the skin whenever possible. While it can be applied over clothing in emergencies, thick clothing may hinder effective compression or allow slippage. If clothing is present, remove or cut it away to expose the limb for direct contact and proper pressure. In immediate threat situations, a “high and tight” application (as high as possible on the limb) can be a rapid and effective initial placement, even if it cuts off blood flow to a larger area.
Steps for Effective Application
After identifying the correct placement, apply the tourniquet to stop blood flow. Pull the strap as tightly as possible around the limb. This initial hand-tightening creates sufficient pressure before engaging the windlass mechanism.
Twist the windlass, a rod-like component on most commercial tourniquets. Continue twisting until bright red, arterial bleeding stops completely or significantly slows. Tighten until no pulse is felt below the application site, indicating complete arterial occlusion. Once bleeding stops, secure the windlass in its clip or fastener to prevent unwinding.
When to Use a Tourniquet
A tourniquet is reserved for severe, life-threatening bleeding. Use it only when direct pressure and other initial methods (e.g., dressings) fail to control significant hemorrhage. This includes spurting or gushing blood, or large volume blood loss or pooling.
Tourniquets are for injuries on arms or legs, not for wounds on the torso, neck, or head. They are relevant in mass casualty incidents or remote environments where immediate medical help is unavailable, as they temporarily stabilize the patient until professional care. While highly effective, tourniquets are a last resort when uncontrolled bleeding poses an immediate threat to life.
After Application and Important Considerations
Immediately contact emergency medical services (EMS) after applying a tourniquet. Professional medical attention is required quickly, as a tourniquet is a temporary measure. Once applied and tightened, do not remove or loosen it if untrained. This can cause a sudden rush of blood back to the injured area, potentially leading to further damage or complications.
Monitor the patient’s condition after application. Mark the application time clearly on the patient’s forehead or the tourniquet itself. This timestamp provides medical personnel crucial information on restriction duration, influencing subsequent medical decisions and care. The goal is to transport the patient to definitive medical care before prolonged restriction causes unnecessary damage.