Put yourself in the shoes of a nurse...

If you had a patient who had two IVs in her arms. One is marked 18/2, the other is marked 22/2. Which would you take out?

Yep, you're right! Obviously I would take out the one marked 22/2...*rolls eyes*

And when you find out that the IV took a medical registrar 8 goes to put in, you'll feel like an idiot =)