OBTAIN A BLOOD SPECIMEN
Venipuncture is the act of puncturing a vein with a needle, usually for the
purpose of withdrawing a specimen of blood. This may be accomplished by using either
a needle and syringe or by using the Vacutainer system.
a. The Vacutainer is a blood-drawing system using a double-ended needle, a
plastic holder, and vacuum tubes. The tubes may be empty or they may contain a
measured amount of anticoagulant or other material.
b. Since most blood specimens do not need to be sterile, the stopper on the
glass tube is not sterile. However, the needle that is inserted into the vein must be
sterile to avoid the spread of infection. The Vacutainer is not used when a sterile blood
specimen is needed such as that needed for a blood culture.
Vacutainer system advantages.
(a) Provides a rapid way to collect several blood specimens from the
(b) Enables filling of several tubes to obtain multiple samples with only
one needle stick.
Vacutainer system disadvantages.
(a) Vacuum tube makes it impossible to draw back on the plunger to
determine if the needle is in the vein. If the vacuum is broken in the tube, another tube
must be used.
(b) The amount of suction created by the Vacutainer can collapse a
small or fragile vein.
The following are terms used in this section with comments that may help you
understand the procedures for obtaining a blood specimen.
a. Palpate. To feel or to examine with the fingertips.
b. Antecubital Fossa. Hollow or depressed area in the joint between arm and