Table 1.

Characteristics of Included Trials

Trials (year)	Country	Group	Surgery	Anesthesia	Intraoperative Analgesia	Outcomes
Chen 2017 [25]	China	Control(n = 29) DEX(n = 30)	abdominal hysterectomy	general anesthesia	remifentanil	1,2,3,4,5
Gao 2018 [26]	China	Control(n = 101) DEX(n = 102)	abdominal operation	general anesthesia	Not specified	1,2,3,6,7,8,9,10
Nie 2014 [27]	China	Control (n = 38) DEX(n = 38)	caesarean section	spinal anesthesia	bupivacaine bupivacaine +DEX	1,3,6,8,9,10,11
Dong 2017 [28]	China	Control(n = 30) DEX(n = 30)	thoracotomy operation	general anesthesia	sufentanil	1,2,3,4,6,7,8,9,10, 11
Qin 2017 [29]	China	Control(n = 29) DEX(n = 29)	partial laryngectomy	general anesthesia	sufentanil+DEX	1,3,6,7,8,9,10, 11
Lu 2017 [30]	China	Control(n = 76) DEX(n = 75)	shoulder arthroscopy	general anesthesia+ brachial plexus block	DEX+ ropivacaine+ remifentanil	1,2,3,5,6,7,9, 11
Ren 2015 [31]	China	Control(n = 41) DEX1(n = 41) DEX 2 (n = 43)	thoracic surgery	general anesthesia	DEX + sufentanil	1,2,3,4,5,6,7,11
Ren 2015 [32]	China	Control(n = 27) DEX1(n = 28) DEX 2 (n = 27)	abdominal hysterectomy	general anesthesia	sufentanil DEX + sufentanil DEX + sufentanil	1,2,3,4,5,6,7,9,11
Xin 2017 [33]	China	Control(n = 47) DEX(n = 46)	laparotomy surgery	general anesthesia	remifentanil	1,2,6,8,9,10,11

1. pain scores at 24 h postoperatively; 2. pain scores at 48 h postoperatively; 3. sufentanil consumption during the first 24 h postoperatively; 4. sufentanil consumption during the first 48 h postoperatively;5. sedation score at 1 h postoperatively; 6. the incidence of PONV; 7. the incidence of pruritus; 8. patient satisfaction; 9. the incidence of bradycardia; 10. the incidence of hypotension; 11. the incidenceof respiratory depression

DEX= dexmedetomidine, PONV= postoperative nausea and vomiting