BackgroundPrevious studies have demonstrated that dexmedetomidine improves the quality of postoperative analgesia. In the present study, we performed a meta-analysis of randomized controlled trials to quantify the effect of dexmedetomidine as an adjuvant to sufentanil for postoperative patient-controlled analgesia (PCA).MethodsPubMed, Embase, the Cochrane Library, and Web of Science were systematically searched for randomized controlled trials in which dexmedetomidine was used as an adjuvant for PCA with sufentanil. In the retrieved studies, we quantitatively analyzed pain intensity, sufentanil consumption, and drug-related side effects.ResultsNine studies with 907 patients were included in this meta-analysis. Compared with sufentanil alone, dexmedetomidine-sufentanil for postoperative intravenous PCA reduced pain intensity at 24h (mean difference (MD)=-0.70points; 95% confidence interval (CI): -1.01, -0.39; P<0.00001) and 48h postoperatively (MD=-0.61points; 95% CI: -1.00, -0.22; P=0.002). Moreover, dexmedetomidine-sufentanil reduced sufentanil consumption during the first 24h (MD=-13.77g; 95% CI: -18.56, -8.97; P<0.00001) and 48h postoperatively (MD=-20.81g; 95% CI: -28.20, -13.42; P<0.00001). Finally, dexmedetomidine-sufentanil improved patient satisfaction without increasing the incidence of side effects.ConclusionsDexmedetomidine as an adjuvant to sufentanil for postoperative PCA can reduce postoperative pain score and sufentanil consumption.