What's the difference?

I'm not an expert on this stuff, but usually the needle is usually only present while installing the IV. After it's placed, the needle is removed, leaving only the catheter.

I wasn't sure if appendicitis would need something larger perhaps?

Anyways, the Dexcom pods are similar to an IV in the way the insertion needle and sensor go in together then the needle retracts.

Oh yeah, then it would be an IV catheter. It was just for fluids and antibiotics, fairly routine I think.