What are the contraindications for the use of a tourniquet?

The reason for identifying the application of a tourniquet as needing to be proximal to the wound relates to its purpose in managing severe bleeding. A tourniquet is designed to restrict blood flow to an extremity in order to control life-threatening hemorrhage. When applied correctly, it occludes arterial blood flow, stopping further blood loss. For optimal effectiveness, this must occur above the site of injury; if placed below the wound, blood may still flow to the injury, allowing bleeding to continue. In this case, a tourniquet applied distal to the wound would fail to provide the intended benefit and could potentially worsen the patient's condition.

Additionally, application over a joint is generally discouraged, as it may not effectively compress the blood vessels, leading to inadequate control of bleeding. Uncontrolled bleeding below the joint would be a significant concern, but it doesn't directly relate to the functionality of the tourniquet itself; the focus should be on addressing bleeding at its source above the injury site. Thus, the critical aspect of this guideline is ensuring that the tourniquet is applied proximal to the wound for it to be effective in controlling hemorrhage.