Dexmedetomidine as an adjuvant for patients undergoing breast cancer surgery A meta-analysis

Background: The goal of this study was to comprehensively evaluate the analgesic and antiemetic effects of adjuvant dexmedetomidine (DEX) for breast cancer surgery using a meta-analysis. Methods: Electronic databases were searched to collect the studies that performed randomized controlled trials. The effect size was estimated by odd ratio (OR) or standardized mean difference (SMD). Statistical analysis was performed using the STATA 13.0 software. Results: Twelve published studies involving 396 DEX treatment patients and 395 patients with control treatment were included. Pooled analysis showed that the use of DEX significantly prolonged the time to first request of analgesia (SMD = 1.67), decreased the postoperative requirement for tramadol (SMD = -0.65) and morphine (total: SMD = -2.23; patient-controlled analgesia: SMD = -1.45) as well as intraoperative requirement for fentanyl (SMD = -1.60), and lower the pain score at 1 (SMD = -0.30), 2 (SMD = -1.45), 4 (SMD = -2.36), 6 (SMD = -0.63), 8 (SMD = -2.47), 12 (SMD = -0.81), 24 (SMD = -1.78), 36 (SMD = -0.92), and 48 (SMD = -0.80) hours postoperatively compared with the control group. Furthermore, the risks to develop postoperative nausea/vomiting (PONV) (OR = 0.38) and vomiting (OR = 0.54) were significantly decreased in the DEX group compared with the control group. The pain relief at early time point (2, 6, 12, 24 hours postoperatively) and the decrease in the incidence of PONV were especially obvious for the general anesthesia subgroup (P < .05) relative to local anesthesia subgroup (P >.05). Conclusion: DEX may be a favorable anesthetic adjuvant in breast cancer surgery, which could lower postoperative pain and the risk to develop PONV. DEX should be combined especially for the patients undergoing general anesthesia.