2-1. Introduction

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.

(1) Vacutainer® system advantages.

(a) Provides a rapid way to collect several blood specimens from the same patient.

(b) Enables filling of several tubes to obtain multiple samples with only one needle stick.

(2) 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.