system
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human
ELI5: salt water injected before sedatives

So, I went to get all four of my wisdom teeth removed yesterday, and just before the nurse injected me with the sedatives, she said that she was pumping salt water through my arm first. Does anyone know why she did that?
gpt
Anytime an IV is started the first thing that gets pushed through it is normal saline - the salt water in question - to "test" the vein and IV. If for some reason the vein blows, or the IV site isn't patent (won't flow correctly) a little bit of salt water in your arm won't make a hill of beans in the long run, but a medication that's outside the vein at very least isn't getting circulated through your system and at worst can do some really serious tissue damage.