Phlebotomy refers to the act of extracting blood from the circulatory system. It is performed by creating a puncture or cut into a vein or artery. It is usually done to obtain a blood sample for diagnosis or analysis, but it can also be a necessary procedure for treating certain blood disorders. It is also commonly done for the purpose of blood donation.
Phlebotomy can be performed by nurses, physicians, or specialized clinical technicians called phlebotomists. Blood is mostly extracted from a vein that is located just below an elbow or on the back of a hand, but certain blood tests may require blood to be drawn from an artery. The skin on the elbow or back of the hand will be wiped with antiseptic. After that, an elastic band will be tied around the arm to make the vein more visible and prevent the blood from flowing away from the arm. The phlebotomy technician will then select an appropriate vein and insert a needle into it. At this point, the elastic band will be released, and the technician will extract a certain amount of blood and remove the needle.
For tests that require only a small amount of blood, a finger stick may be used. A small needle or lance will be used to make a small cut on the surface of a fingertip, and the blood will be collected in a glass tube. The phlebotomy technician may squeeze the fingertip to get more blood to surface. The amount of blood extracted differs according to the purpose of the phlebotomy. Those who are donating blood usually have 500 ml of blood drawn from their bodies in a single session. As for laboratory analysis, the volume of blood drawn is typically one or several 5 to 10 ml tubes. Therapeutic phlebotomy usually requires a higher amount of blood than blood analysis and donation.
The phlebotomy procedures that are performed on adults and teenagers are different from those that are used on infants and young children. Babies and young children have smaller veins, as well as a greater tendency to squirm than adults and teenagers when undergoing a medical procedure. Squirming during phlebotomy can increase the risk of injuries, and phlebotomy technicians need to know how to use the right techniques to ensure the safety of babies and young children. They can try to calm their pediatric patients by praising them for their bravery. If this fails, they may have to resort to restraining them physically. This is best done by parents or guardians, but in the event that they are not present or too distressed by the process, the task can be performed by medical personnel.
When performing capillary puncture, the best location to extract blood from a baby is the heel. The blood should be collected from the two side corners on the underside of the heel, and the heel should be pre-warmed to improve circulation. The most ideal place for performing venipuncture on infants and young children is the dorsal vein on the hand. This technique reduces hemolysis, damage to red blood cells, and risk of dilution. The procedure should be performed with a 21 to 23 gauge, ¾ to 1-inch needle, as well as a butterfly wingset. The needle must be inserted slowly, so that it will not pierce through the vein.