Vacutainer is a device that uses the principle of negative pressure to automatically and quantitatively collect venous blood samples. It realizes the collection by pre-adjusting the vacuum degree of the blood collection tube to different degrees. During the collection process, different vacuum levels and the pressure of the surrounding environment will determine the volume of blood collected by the vacutainer. The greater the pressure difference between the inside and outside of the Vacutainer, the more blood it collects.
The working principle of the Vacutainer is to create a low-pressure environment inside the vacuum tube, so that when the patient’s vein is punctured, the blood will be automatically sucked into the vacuum tube. After the blood enters the tube, the vacuum is continuously reduced until it reaches a stage of equilibrium with the surrounding environment. According to the characteristics of blood and collection requirements, choosing a vacutainer with different vacuum degrees can ensure that an appropriate amount of blood is collected.
This acquisition method has many advantages, such as fast, accurate and hands-free. At the same time, the use of vacutainer can also reduce pain and discomfort for patients.
A good way to test the Drawing Volume of the Vacutainer
Vacutainer needle are double ended, with one side being encased in a thin rubber coating for safety. When the needle is screwed into the translucent plastic needle holder, the rubber needle is inside the holder, and the exposed needle will be inserted into the vein.
When a vacutainer tube is inserted into the holder, its rubber cap is punctured by the inner needle and the vacuum in the tube pulls blood through the needle and into the tube. The filled tube is then removed and another can be inserted and filled the same way. The amount of air evacuated from the tube predetermines how much blood will fill the tube before blood stops flowing.
