A tourniquet is a device designed to stop massive, life-threatening bleeding from an arm or leg, typically used when direct pressure is ineffective or impractical. Its application is a rapid, time-sensitive intervention that can prevent a person from losing a fatal amount of blood before medical help arrives. Understanding the proper placement and mechanical steps for use is paramount to ensure the device works effectively.
The Exact Location for Application
The standard recommendation is to place the tourniquet approximately 2 to 3 inches (5 to 8 centimeters) above the bleeding site, positioning it closer to the torso (proximal) on the injured limb. This specific distance ensures the device is applied to clean, undamaged tissue, allowing for better compression of the artery. Placing the device too close to the edge of the wound may compromise the sealing of the blood vessels.
This placement must be on a section of the limb containing a single long bone (like the humerus or femur) to allow for effective compression of the major artery against the bone. Applying the tourniquet over a joint, such as the knee or elbow, is avoided because the complex, non-uniform anatomy prevents consistent pressure, making it difficult to fully stop the blood flow. If the wound is located close to a joint, the device must be placed higher up on the limb, above the joint, to ensure single-bone placement.
For maximum effectiveness, the tourniquet should be applied directly to the skin if possible. It can be placed over clothing if necessary to save time, provided the clothing is not bulky and can be smoothed out. If bleeding is not controlled by the first tourniquet, a second one should be applied directly above the first, closer to the body.
Steps for Effective Application
Once the correct location is determined, the mechanical application requires immediate and deliberate action. The strap should first be pulled as tightly as possible to remove all slack and begin applying circumferential pressure to the limb. This initial tightening ensures the device is snug before the mechanical advantage is used.
For commercial devices utilizing a windlass rod, this rod is then twisted to further increase the pressure on the limb. The twisting must continue until the bleeding stops completely and the pulse in the limb below the tourniquet (distal pulse) can no longer be felt. A properly tightened tourniquet will be uncomfortable or even painful, which is an indication that the device is correctly occluding arterial blood flow.
After the bleeding has ceased, the windlass rod must be secured in its clip or locking mechanism to prevent it from unwinding and losing tension. Securing the windlass ensures the pressure is maintained until medical professionals can take over care. The final step is to clearly note the time of application on the device itself or on the patient, as this information is crucial for medical providers assessing the risk of tissue damage.
Crucial Safety Warnings and Limitations
The use of a tourniquet is reserved strictly for life-threatening hemorrhage that cannot be controlled by direct pressure alone. It is a temporary measure designed to buy time until advanced medical care is available, not a complete treatment. Once the device is applied and effective, it must not be loosened or removed by untrained personnel. Removing it can cause severe re-bleeding, potentially releasing harmful metabolic byproducts into the bloodstream.
Leaving a tourniquet in place for an extended period risks damaging underlying tissues due to lack of blood flow (ischemia). Nerve damage is the most common complication, but muscle and soft tissue damage can also occur. Permanent damage generally becomes more likely after two hours of continuous application.
The goal is to transport the patient to definitive care as quickly as possible, ideally within two hours of application. While stopping the bleed is the immediate priority, the time stamp allows medical teams to monitor the patient for complications like post-tourniquet syndrome or compartment syndrome. The tourniquet is only a stopgap measure, reinforcing the need for immediate, professional medical intervention.