A tourniquet is a temporary device designed to stop severe bleeding from a limb when direct pressure alone is insufficient. Its primary function involves compressing blood vessels to restrict blood flow to an injured area, preventing life-threatening blood loss. Proper application is crucial, as incorrect placement can fail to control bleeding and may cause additional harm. Understanding the precise techniques for applying a tourniquet is fundamental for its safe and effective use.
General Principles of Tourniquet Placement
Effective tourniquet application follows universal guidelines to ensure blood flow is completely stopped. The device should be positioned as high as possible on the injured limb, regardless of the exact wound location, and situated proximal to the injury, meaning closer to the body’s core. This “high and tight” placement aims to compress the main artery supplying blood to the limb.
The tourniquet should ideally be applied directly to the skin. If immediate application is necessary and clothing obstructs direct skin contact, the tourniquet can be placed over the clothing, but it should be adjusted to direct skin contact later if the situation permits and is safe. The ultimate goal is to occlude arterial blood flow completely, which is achieved by sufficient tension and proper positioning.
Arm Tourniquet Placement
When applying a tourniquet to an arm, the ideal placement is on the upper arm, on the bicep or tricep area. This positioning helps to compress the brachial artery, which is the primary blood vessel supplying the arm. Even if the bleeding wound is located lower on the forearm or hand, the tourniquet must still be placed high on the upper arm to ensure effective blood flow restriction.
It is important to avoid placing the tourniquet directly over the elbow joint. The bony structure of the elbow prevents the tourniquet from achieving the necessary circumferential compression to occlude blood flow effectively. Furthermore, applying pressure directly over a joint can be less stable, compromising the tourniquet’s ability to control severe bleeding.
Leg Tourniquet Placement
For a leg injury requiring a tourniquet, the device should be placed on the upper thigh, positioned as high as possible. This high placement targets the femoral artery, the largest artery in the leg, ensuring comprehensive blood flow occlusion to the lower limb. This principle applies even if the bleeding originates from a wound lower down, such as the calf or foot.
The tourniquet should not be positioned directly over the knee joint. The anatomical configuration of the knee, with its prominent bones and tendons, makes it difficult to achieve the firm, even compression required to stop arterial bleeding. Incorrect placement over the knee can render the tourniquet ineffective and may lead to continued blood loss.
Crucial Considerations for Effective Placement
Ensuring the tourniquet is tightened sufficiently is important; the goal is to completely stop the arterial bleeding. Verification of effective application includes the cessation of bright red, spurting blood and the absence of a palpable pulse distal to the tourniquet. If bleeding persists after initial tightening, the tourniquet may need further tightening or slight repositioning to achieve full arterial occlusion.
Several common errors can compromise the effectiveness of tourniquet placement. Applying the tourniquet directly over a prominent bone or joint, such as the elbow or knee, should be avoided, as these areas do not allow for adequate compression of blood vessels. Placing the tourniquet over bulky items within pockets, such as wallets or cell phones, also prevents proper direct pressure on the limb and can hinder effective blood flow stoppage.
Applying a tourniquet too loosely is a serious mistake, as it can worsen bleeding by occluding venous return while still allowing arterial flow, leading to increased blood accumulation in the limb. Once a tourniquet is correctly applied and bleeding has stopped, it should not be removed by individuals without medical training. It is also important to note the time of application, as this information is useful for medical personnel upon arrival.