about the air bubbles -
"A blood clot or other solid mass, as well as an air bubble, can be delivered into the circulation through an IV and end up blocking a vessel; this is called embolism.
Peripheral IVs have a low risk of embolism, since large solid masses cannot travel through a narrow catheter, and it is nearly impossible to inject air through a peripheral IV at a dangerous rate. The risk is greater with a central IV."
Chemistry - Intravenous therapy
and if u're scared about injecting, remember that drug addicts inject themselves all the time but you rarely hear about them dying or getting seriously injured from infections or the actual injection.
