Based on your description, I personally think that, first of all, a brief summary is: Children have swollen hands or local swelling after using black needles for infusion, but there is no problem with purple needles. What is this? Caused by. First point, if it is the nurse's fault, I personally think the possibility is relatively small, but I do not rule it out. If they are all the same nurse, then this situation can be ruled out. The second point is that in medicine, in order to facilitate handling and identification, many medical equipment are distinguished by color, and the biggest difference lies in the flow rate. For example, the flow rate per minute of black is 80, Purple is 60, and of course there is blue. Blue is generally normal traffic. What this means is that it may be because the child is not very old and therefore cannot keep up with his physical condition. If a needle with a large flow rate is mistakenly used, swelling may easily occur. At this time, just contact the nurse or doctor in time. , of course, the specific situation depends on the actual situation. I hope the above suggestions can bring you some help, thank you.