Effectiveness of analgesia with hydromorphone hydrochloride for postoperative pain following surgical repair of structural congenital malformations in children: a randomized contro... oleh Yongying Pan, Yimin Wang, Dongxu Lie, Di Liu, Xi Chen, Zeyan Wu, Liumei Chen, Huaizhen Wang, Liangming Peng, Huiying Liang, Xingrong Song, Baisong Zhao