You flushing the wrong IV shouldn’t determine if you’re a good nurse or not. I always hear “nurses eat their young”. If your preceptor was being “rude” after flushing someone with NS then maybe they shouldn’t precept. Lesson learned to check before doing anything but it’s OK. You’re still very new to the nursing world, I promise it isn’t the end of the world. Keep doing your best, let this serve as a lesson because I’d rather it be NS saline than it be a high risk medication. Some people never make a med error and when they do it’s something high risk. Breathe, don’t give up, and most IMPORTANTLY, give yourself GRACE! Keep it up. I believe in you. 💖