What must be ensured when applying a tourniquet?

When applying a tourniquet, it is critical to occlude both venous and arterial flow. The purpose of a tourniquet is to achieve complete vascular occlusion in the affected limb, allowing for the control of severe hemorrhage, particularly in traumatic injuries. By stopping both arterial and venous blood flow, the tourniquet reduces blood loss effectively, preventing further complications and potentially saving the patient's life.

Failing to occlude arterial flow can lead to continued bleeding from the injury, while incomplete venous occlusion may allow for venous blood to seep back into the general circulation, leaving the bleeding uncontrolled. This is essential knowledge for any medical personnel dealing with trauma cases, as improper application could have severe repercussions for the patient's condition.

Other options, while they may address relevant considerations in tourniquet use, do not capture the primary and immediate purpose of how a tourniquet should function effectively in an emergency setting.