A tourniquet is a medical device that applies significant circumferential pressure to a limb. Its purpose is to completely compress the blood vessels beneath it, stopping the flow of blood. This intervention is reserved for situations involving life-threatening external bleeding, known as hemorrhage, which poses an immediate risk of death. The device works to prevent a person from rapidly losing a fatal volume of blood before medical professionals can provide definitive care.
Assessing the Need for Tourniquet Use
The decision to use a tourniquet should only occur when facing uncontrolled bleeding that threatens the person’s life within minutes. Initial efforts should always involve applying direct, firm pressure to the wound, often with a gauze or thick dressing, for several minutes to see if the bleeding can be stopped or slowed. If the bleeding is massive, spurting, or soaking through the pressure dressing quickly, then a tourniquet is indicated.
A tourniquet is also the appropriate response for catastrophic injuries where direct pressure is impossible or ineffective, such as a traumatic amputation or a wound with multiple impaled objects. The severity of the hemorrhage must outweigh the risks associated with cutting off circulation to the limb. It is considered a last resort when less invasive methods of bleeding control have failed.
Precise Placement on the Arm
When applying a tourniquet to the arm, the goal is to place it high enough to compress the single humerus bone, which allows the pressure to effectively collapse the main brachial artery running alongside it. The most current guideline recommends placing the tourniquet approximately two to three inches above the wound site, between the injury and the torso. This strategy, known as deliberate placement, helps maximize the portion of the limb that retains normal blood flow, potentially reducing the overall damage from lack of circulation.
If the source of the bleeding is not immediately visible, or if the environment requires quick action, the device should be applied “high and tight” on the upper arm, as close to the armpit as possible. Regardless of the exact placement, it must be on the upper arm (the brachial region) and never on the forearm. The forearm contains two bones, the radius and the ulna, which prevent the tourniquet from effectively compressing the arteries against a single solid surface.
It is crucial to avoid placing the tourniquet directly over any joint, such as the elbow, because the anatomical structure makes the device ineffective and increases the likelihood of nerve damage. After securing the strap, the mechanical windlass must be twisted until the bleeding stops completely and the pulse below the tourniquet is no longer detectable. The device must be tight enough that two fingers cannot be slipped beneath the strap.
Essential Steps Following Application
Once a tourniquet has been applied and the severe bleeding has ceased, the next immediate step is to document the exact time of application. This time, often referred to as the “T-time,” must be visibly marked on the tourniquet device itself or on the patient’s forehead using a permanent marker. Medical personnel rely on this information to manage the patient’s care, as prolonged lack of blood flow to the limb can lead to tissue damage. The tourniquet should remain in place and must not be loosened or removed by anyone who is not a medical professional, even if the person complains of pain. Loosening the device can cause a sudden, dangerous rush of blood back into the body, potentially releasing toxins that have built up in the limb.
The patient requires immediate transport to a hospital for definitive medical treatment. Continuously monitor the wound to ensure the bleeding does not restart, as this indicates the need for a second tourniquet to be placed just above the first one.