When using a syringe, how do you tell when you have entered a vein?
A) The plunger will begin to move on its own.
B) The blood will automatically fill the syringe.
C) A flash of blood will appear in the syringe hub.
D) You have to pull the syringe back to see whether any blood enters the syringe.

Question

Quizplus · Accepted Answer

When using a syringe to access a vein, a flash of blood will appear in the syringe hub, confirming that the needle has successfully entered the vein. This is the most reliable way to ensure that you have successfully accessed the vein. Option A is incorrect because the plunger will only move on its own if you have accidentally entered an artery, which can be dangerous. Option B is incorrect because blood will not automatically fill the syringe unless it is under pressure, such as when using a vacutainer system. Option D is incorrect because this method of checking for blood in the syringe can be unreliable and may result in accidental removal of the needle.

When Using a Syringe, How Do You Tell When You