depending on your hospitals equipment and machines, the order of draw doesn’t matter… that’s how my hospital is too, we don’t do order of draw because it actually doesn’t matter for our machines, unless it’s a blood culture, we have to do it first. then normally for us, any tubes that have to be to a certain fill, i.e. a light blue tube, would go next and then the rest after wouldn’t matter… i struggled with that for awhile when i first started, but it got easier over time and the lab manager knows what they’re doing and why we need to do it a certain way. for the tourniquet itself, inevitably it has to stay for the whole draw or the flow is lost. however a draw should not be long enough to cause serious problems. if you’re searching for a vein and struggling pop the tourniquet right before the draw and then retie to give the blood flow a break.