Letter to the EditorEfficacy of Nalbuphine as an Adjuvant to Ropivacaine in Ultrasound-guided Supraclavicular Brachial Block A Prospective Randomized Controlled StudyRen, Yifeng MD, PhD; Liu, Hong MD, PhD; Wang, Yuting MD; Fu, Xi MD; You, Fengming MD, PhD Author Information Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu Sichuan Province, China Y.R. and H.L. contributed equally as co-first authors. The authors declare no conflict of interest. The Clinical Journal of Pain: February 2021 - Volume 37 - Issue 2 - p 158-159 doi: 10.1097/AJP.0000000000000899 Buy Metrics Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.