If a 20-year-old male has a large laceration with rapid bleeding, what should you do?

In the case of a large laceration with rapid bleeding, the primary goal is to control the bleeding effectively and quickly to prevent significant blood loss, which can be life-threatening. Applying a tourniquet proximal to the wrist is appropriate when there is severe bleeding from an injured limb that cannot be controlled through direct pressure alone. This method can effectively stop the blood flow to the injured area, allowing for improved chances of survival until further medical assistance can be provided.

Using a tourniquet in such scenarios is recommended particularly when dealing with arterial hemorrhage, where blood loss can occur rapidly. Applying the tourniquet proximal to the injury restricts blood flow beyond the point of injury, thereby controlling the bleeding.

While applying pressure to the brachial artery and wrapping the wound with pressure bandages are valid methods to control bleeding, they may not be sufficient in the case of a large laceration and rapid bleeding. Additionally, administering high-flow supplemental oxygen is not directly related to controlling the bleeding, and while it may be beneficial in managing the patient's overall condition, it does not address the immediate need to stop the bleeding. Thus, using a tourniquet proximal to the injury site is the most effective action in this critical situation.