Once the hypodermic needle has been inserted into the vein, compression is applied to the vein. This is usually done by pushing on the vein with some guaze or a bandage, so that the vein collapses and blood stops flowing through it.
In this state, the vein walls should be touching and there should be very little stagnant blood in the vein.
At this point, a "Sclerosing agent" is injected into the vein. A sclerosing agent is a chemical that is poisonous to the living tissues that make up the vein wall and so it kills them. The sclerosing agentcanuses the vein to constrict immediately. |
