Well, quik clot type products are biochemically active coagulants. They effectively increase the propensity of your blood to clot up and form a thrombus in a n emergency situation. This is good. However, at the same time they increase the propensity of your blood to form a thromboembolism, which is nothing more than a mass of clotted blood that is floating around in your blood stream, waiting to lodge somewhere important and unintended, like you lungs, heart, or brain. The risk is even greater with a large vessel, emergent type situation than with a smaller wound. The larger vessel makes it easier for a clump of clotting blood or worse, a clump of the clotting agent(think lumps in batter, moistened and coherent on the outside while a raw powder on the inside, on a microscopic scale)to break loose and enter circulation.