“…Supplementary 18,[20][21][22][25][26][27]29,30,32,34,36,40,41,44,45,50 cardiac or thoracic surgery (six trials), 19,23,35,37,38,53 orthopedic surgery (ten trials), 24,28,31,33,39,43,[47][48][49]51 and other surgery (three trials). 42,46,52 General anesthesia was used in 34 trials; one trial used PCA during and after a uterine artery embolization procedure, 29 and one used either general or regional anesthesia.…”