Table 2.

Outcomes.

Outcomes	References	DEX (n)	Control (n)	Estimated benefit [95% CI]	P value	I2 (%)
Pain intensity at rest
1 h postoperatively	7,21–25,28–31	256	238	WMD = −1.57 [−1.94, −1.20]	0.00001	89
2 h postoperatively	7,22–25,28–31	235	215	WMD = −1.46 [−1.82, −1.10]	0.00001	89
4 h postoperatively	7,24,25,29–31	145	145	WMD = −1.37 [−1.76, −0.97]	0.00001	84
6 h postoperatively	7,21,23–25,28,30,31	186	188	WMD = −1.26 [−1.61, −0.92]	0.00001	83
8 h postoperatively	7,22,29–31	140	120	WMD = −1.02 [−1.41, −0.64]	0.00001	70
12 h postoperatively	7,21,24,25,29–31	166	168	WMD = −0.55 [−0.88, −0.23]	0.0009	69
24 h postoperatively	7,21–23,25,29,31	181	163	WMD = −0.34 [−0.68, 0.00]	0.05	59
Pain intensity on movement
1 h postoperatively	22,29,30	90	70	WMD = −1.71 [−2.39, −1.03]	0.00001	86
2 h postoperatively	22,29,30	90	70	WMD = −1.80 [−2.25, −1.36]	0.00001	70
8 h postoperatively	22,29,30	90	70	WMD = −1.29 [−1.57, −1.02]	0.00001	32
Other outcomes
Morphine-equivalents 0–24 h (mg)	21,23,28–31	151	153	WMD = −8.54 [−11.96, −5.13]	0.00001	95
Time to first analgesic request (min)	7,21–31	316	278	WMD = 257.57 [209.86, 305.28]	0.00001	93
PONV	7,21–31	316	278	RR = 1.37 [0.52, 3.62]	0.52	0
Hypotension	7,21–31	316	278	RR = 2.20 [0.67, 7.23]	0.19	0
Bradycardia	7,21–31	316	278	RR = 2.20 [0.81, 5.97]	0.12	0
Somnolence	22,23,28,31	120	100	RR = 1.54 [0.07, 36.11]	0.79	0

DEX group vs. control group for all comparisons.

Pain intensity was scored with a visual analog scale as: 0 = no pain, 10 = the most severe pain imaginable.

Morphine-equivalents were calculated as: morphine 10 mg = tramadol 100 mg = fentanyl 0.1 mg, intravenously.

DEX, dexmedetomidine; PONV, postoperative nausea and vomiting; WMD, weighted mean difference; RR, risk ratio; CI, confidence interval.