So the other night I was trying to flush a patients iv that had NS @75. I was giving morphine. So I flushed a little, gave the morphine slowly, then went to flush and was push/pausing it but it stopped flushing. It was fine and then all the sudden wouldn't push. I didn't move the iv, pushed the morphine slow like you're supposed to, and it just wouldn't flush. Then it started swelling up. It had infiltrated but I'm just wondering what I did wrong. The iv was obviously in before I gave the morphine but then it blew after I gave it. Some nurse told me I could have pushed it too slow. She said u can push it too fast and too slow but I don't understand. Can anyone explain this and what I did wrong?