It is standard to do nerve blocks under general anesthesia in children. This is not the same in adults. These are two different kind of populations. One of the biggest studies in this area was published in Anesth Analg 1996 which was a French prospective study that involved 164 anesthesiologists over 38 institutions and 85 thousand pediatric patients that had general anesthesia. In this study there were 24 thousand blocks. The incidence of complications was very low.

One of the important issues is:  Nerve block in children should be performed by experienced anesthesiologist with training and experience in this area. In this way we keep complications low. It will be good for you to review this study.