How to prevent to collect blood vessel to reverse flow

Since the creation of vacuum blood collection in 1937, the vacuum blood collection tube has become increasingly common, gradually replacing the method of syringe blood collection, which has increasingly standardized the blood collection skills and improved the quality and speed of test specimens. In 2004 it was reported that there was a risk of infection due to the difference in pressure between the intravascular pressure and the intravascular pressure in the vacuum sampling. It has been stated that serrata marcescens has been detected from some vacuum sampling vessels, and that safer blood collection techniques have led to attention from all circles if there is a risk of infection in the blood flow. This article describes how to prevent reverse flow:

Why it can cause blood reflux: The "vacuum" of a vacuum collector is a condition where there is no air at all, below atmospheric pressure. The pressure (negative pressure) of vacuum sampling vessel is set according to the amount of blood collected.

When the pulse band is tightened, the intravascular pressure rises - blood flows into the cubital vein under vacuum pressure after the needle is inserted. The pre-load negative pressure is exhausted. Blood collection is completed. At this point, intravascular pressure = vacuum blood collection. At the end of blood collection, because the intravascular pressure in the removed exorcised blood band is fast and low, it is more important to return to normal pressure. At this moment, the intravascular pressure is < the intravascular pressure for vacuum collection, and there is a risk that the pumped blood will return to the blood vessel again.

Blood collection method to prevent blood reflux: remove the exorcism band when collecting blood. Adopted blood to prevent touching the blood needle spit out some, blood collection do not remove the blood drive belt, adopted blood to prevent touching the blood needle spit out some (blood to make the tube down, prevent blood needle spit out some and have adopted the blood touch), this can be prevented