Article Text

Download PDFPDF
Effective Dose of Intravenous Dexmedetomidine to Prolong the Analgesic Duration of Interscalene Brachial Plexus Block: A Single-Center, Prospective, Double-Blind, Randomized Controlled Trial
  1. RyungA Kang, MD*,,
  2. Ji Seon Jeong, MD, PhD*,
  3. Jae Chul Yoo, MD, PhD,
  4. Ju Hyun Lee, MD*,
  5. Soo Joo Choi, MD, PhD*,
  6. Mi Sook Gwak, MD, PhD*,
  7. Tae Soo Hahm, MD, PhD*,
  8. Jin Huh, MD, PhD*, and
  9. Justin Sangwook Ko, MD, PhD*
  1. *Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul
  2. Department of Anesthesiology and Pain Medicine, Kangwon National University School of Medicine, Chuncheon
  3. Department of Orthopedics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
  1. Address correspondence to: Justin Sangwook Ko, MD, PhD, Department of Anesthesiology and Pain medicine, Samsung Medical Center, 81 Irwon ro, Gangnam gu, Seoul 06351, Korea (e-mail: jsko{at}


Background and Objectives Intravenous (IV) dexmedetomidine (DEX) is reported to prolong the analgesic duration after single-shot interscalene brachial plexus block (ISBPB). However, the effective analgesic dose of IV DEX remains undetermined. Therefore, we aimed to elucidate the clinically relevant dose of IV DEX to prolong the analgesic duration of ISBPB.

Methods Seventy-two patients scheduled for arthroscopic shoulder surgery received ISBPB with 15 mL of 0.5% ropivacaine with 1:200,000 epinephrine and were randomly assigned to 1 of 4 groups (n = 18, each): (1) IV normal saline (control), (2) IV DEX 0.5 μg/kg (DEX 0.5), (3) IV DEX 1.0 μg/kg (DEX 1.0), and (4) IV DEX 2.0 μg/kg (DEX 2.0). The primary outcome was time to the first pain at surgical site.

Results The median (interquartile range) duration of analgesia was significantly prolonged for the DEX 2.0 (874 minutes [727–1153 minutes]) compared with 656 minutes (590–751 minutes), 703 minutes (644–761 minutes), and 696 minutes (615–814 minutes) for the control, DEX 0.5 and DEX 1.0 groups, respectively (P = 0.001, P = 0.008, and P = 0.003, respectively). Postoperative cumulative IV morphine equivalent consumption at 24 hours was significantly lower in the DEX 2.0 compared with the control, DEX 0.5 and DEX 1.0 groups (P < 0.001, P < 0.001, and P = 0.007, respectively). There were no significant differences in the incidence of intraoperative hypotension and the number of patients who required ephedrine after the pairwise group analysis. Also, there were no significant differences on the durations of motor blockade and sedation and the incidence of bradycardia.

Conclusions Intravenous DEX at a dose of 2.0 μg/kg significantly increased the duration of ISBPB analgesia without prolonging motor blockade and reduced the cumulative opioid consumption at the first 24 hours in patients undergoing arthroscopic shoulder surgery.

Clinical Trial Registration This study was registered at the Clinical Trial Registry of Korea, identifier KCT0002119.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • R.K. and J.S.J. contributed equally as first authors.

    The authors have no sources of funding to declare for this article.

    The data were presented in part at the 36th Annual European Society of Regional Anaesthesia and Pain Therapy Congress; September 13 to 16, 2017; Lugano, Ticino, Switzerland.

    The authors declare no conflict of interest.