Why use a tourniquet when drawing blood?

Never leave a tourniquet on for more than 1 min.

You can use it as a tourniquet for scientific experiments or for engorging veins for blood drawing. Also can be used in blood clotting studies where a constant pressure is required for the test to be accurate, where a small cut is made in the skin and the time taken for the blood to clot is measured.

no longer than a minute and a half to two minutes once you get the needle into the vein you should tell the person to relax the fist first then remove the tourniquet if left on too long you can obliterate the blood supply and cause tissue damage

You've offered to apply a Band-Aid, when what I need is a tourniquet. Please don't apply a tourniquet unless you are certain that you can quickly deliver this patient to a doctor. Because direct pressure has not stopped the blood from gushing out of the wound, a tourniquet seems to be necessary.

as soon as blood is drawn from the vein the tourniquet should be immediately open from the arm. otherwise there can be obstacle in the blood flow.

till first signs of blood eg in venepuncture or cannulation. The second you see blood coming out you release the tourniquet.

its cutting the blood flow off to that limb, so its cutting off the circulation to that arm, but your at the doctors and it will be taking off in time so nothing will happen :)

To stop a very badly bleeding wound, or to draw blood in medical situations. It is also used to inject recreational or medicinal products directly into the vein as it is easier to locate when a tourniquet is used.

You don't. A tourniquet is a really tight fitting band intended to compress tissue and vessels to the point where there's no blood flowing past the tourniquet. It's useful to stop heavy bleeding, but doesn't do any good at all for an infection. As the goal of a tourniquet is to stop all blood flow, it will also begin to starve the healthy tissue "downstream" of the tourniquet of blood, which will lead to further…

In the process of limiting further blood loss, the tourniquet also drastically deprives the limb tissues of oxygen

It is used to compress any blood vessel

Torque applies to horsepower. You are thinking of tourniquet. If you lose a limb a tourniquet prevents excessive blood loss.

to allow the blood to continue flowing. the tourniquet backs up the blood and makes the veins more big and firm. After the needle is in ur good to go. but the blood has to flow

A tourniquet is a method of stopping bleeding that stops all blood flow. Tourniquets are what you are looking for. tourniquet A tourniquet is a constricting or compressing device used to control venous and arterial circulation to an extremity for a period of time. Pressure is applied circumferentially upon the skin and underlying tissues of a limb; this pressure is transferred to the walls of vessels, causing them to become temporarily occluded. A tourniquet. tourniquet…

It would. Remember, almost anything that can cut off blood flow will make a good tourniquet in an emergency. Just don't leave it on too long.