Phlebotomy, also known as venesection, is performed by a nurse or a technician known as a phlebotomist. Blood is usually taken from a vein in the upper forearm (antecubetal fossa) is most often chosen for venipuncture. Arterial blood is required for blood gas measurements. Smaller quantity of blood may be obtained from the capillary bed by puncture of the skin ” a capillary puncture or skin puncture. Capillary blood is often used for point of care tests (POCT).

Venous blood can be collected in many ways. Venipuncture methods can vary depending on the test requirements, age, and physical condition of the patients. The sites to use are those in forearm, wrist, or ankle but the common is forearm veins. This is because forearm veins are generally more fuller and larger than other veins. Three main veins in the forearm are cephalic, median cubital, and median basilic.

An evacuated tube and needle collection system or a sterile syringe and needle can be used for collection of blood from a vein. BD Vacutainer system tubes are widely used where BD represents the company Becton, Dickinson and company, which first marketed these tubes. Evacuated tubes can be combined to use in an infusion or butterfly set.

In the evacuated tube method, the hypodermic needle used to puncture the vein is double ended, the second shorter needle being shrouded for safety by the holder. One end of a two-way needle is partially attached by means of a holder to the rubber stopper of a specially prepared vacuum tube, while the other end of the needle is inserted into the vein. When a Vacutainer test tube is pushed down into the holder, its rubber cap is pierced by the second needle and the pressure difference between the blood volume and the vacuum in the tube forces blood through the needle and into the tube. The filled tube is then removed and another can be inserted and filled the same way. It is important to remove the tube before withdrawing the needle, as there may still be some suction left, causing pain upon withdrawal. The Clinical and Laboratory Standards Institute (formerly NCCLS) has published standards for use of evacuated tubes for blood specimen collection.

In patients with difficult veins the use of a syringe and needle system is made for collection of blood. Vacuum of BD vacutainer tubes may cause collapsing of smaller veins in some patients, and in this case use of syringe and needle is preferred. In case of collection for babies, and small children with small veins, for obese patients with hard to find veins, for patients receiving intravenous therapy with scarred veins, and for veins other than those in antecubital fossa (wrist, back of hand, ankle, foot, or scalp), an infusion set called butterfly is often used.

Phlebotomist can perform multiple duties as per the requirement of the work setting. Phlebotomist is primarily concerned with assisting doctors. Coordinating with nurses may be one of the other duties. Blood sample collection or tissue samples from patients is also the duty of a phlebotomist as a hospital technician.

Proper patient identification is an important process before sample collection for a phlebotomist. Correct puncture or incision of patients skin to take specimens is the responsibility of a phlebotomist. Enough volume of blood or tissue should be taken for the specific test and this is the duty of the phlebotomist. Phlebotomists role also is to correctly label the sample and transport the labeled samples to the testing lab on time.

To achieve these competencies, training from a certified program, or on job training, or cross training from other healthcare profession can be completed by the phlebotomists. Professional association certification leads to fine tuned skills for already employed technicians / phlebotomists and learning basic skills for new graduates.