Venipuncture is the collection of blood from a vein and this is usually done for laboratory testing. Blood is normally drawn from a vein on the top of the hand or from the inside of the elbow. Venipuncture requires good skills in order to perform the procedure not only correctly, but also painlessly too. There are some slight risks associated with venipuncture and they may include: excessive bleeding, feeling light-headed, fainting, hematoma (accumulation of blood under the skin), and infection.
The area where the blood is to be drawn from is cleaned first with a germ-killing solution. The medical technician or phlebotomist will wrap a flexible band on the upper part of the arm so it will apply some pressure to that area which makes the vein enlarge with blood. Then a needle is gently inserted into the vein. Blood is collected into an attached vial or tube that is airtight and the flexible band is then removed from the arm. If more than one vial of blood is needed, it will not require another puncture. When the necessary blood is collected, the needle will be removed, and the puncture site will be covered to stop the bleeding.
Arteries and veins in men, women and children differ in size. Obtaining blood samples from some individuals can be more challenging than from other individuals. Most adults will only feel mild pain from the puncture or a stinging sensation. There might be a slight throbbing in the area after a venipuncture. Young children sometimes have venipuncture performed in different parts of the body, such as the hand or foot. It is typically easier to puncture surface veins on the hand or foot, but it is more painful. Parents can request that blood be drawn from the arm, especially if their child is at least a couple of months old.
It is not uncommon for some adults and children to feel some fear when having blood drawn. Some individuals are afraid of the needles, while others are frightened at the sight of blood. When multiple vials of blood are collected it can seem like a large amount. In fact blood samples that are normally taken are actually very small. A typical single vial contains about five milliliters, which is about one teaspoon. Even if several vials of blood have to be drawn it usually amounts to no more than one ounce. Compared to the standard blood donation which is about sixteen ounces, one ounce is really small.
Venipuncture can also happen when patients have intravenous (IV) lines started. In most of these cases, the skin on the hand is pierced and a vein is accessed so medications or fluids can be given intravenously. This type of venipuncture procedure is a little different, and sometimes can a little more involved. When there is an IV line present, blood can be drawn from this line. In other words, there is no need to for another venipuncture procedure. IV lines are very useful in hospitals because some patients require frequent blood tests.