Efficacy and safety of dexmedetomidine combined with tramadol for patient-controlled intravenous analgesia in Chinese surgical patients: A systematic review and meta-analysis

BACKGROUND: Patient-controlled intravenous analgesia (PCIA) has been suggested as an effective method of pain relief. There are several randomized controlled trials (RCTs) of dexmedetomidine (DEX) combined with tramadol for PCIA in Chinese surgical patients. The purpose of this study was to perform a systematic review and meta-analysis to evaluate the efficacy and safety of DEX combined with tramadol for PCIA in Chinese surgical patients from current data. METHODS: The RCTs of DEX combined with tramadol for PCIA were gathered from the PubMed, Excerpta Medica Database, Cochrane Library, Cochrane Library, China National Knowledge Infrastructure database, and VIP databases. After data extraction and quality assessment of the included RCTs, RevMan 5.3 software was employed for the meta-analysis of visual analog scale (VAS) scores, Ramsay sedation scores, effective pressure times for PCIA, tramadol consumption, and safety. RESULTS: Fourteen RCTs were included. Compared with tramadol alone, postoperative intravenous tramadol-DEX combination PCA led to lower VAS scores (weighted mean differences [WMD](12h) = 0.14, 95% confidence interval [CI] v1.50 to 1.79; WMD(24h) = 0.78, 95% CI −0.92 to −0.62; WMD(48h) = 0.51, 95% CI −0.66 to −0.38; all P < .05), lower Ramsay sedation scores (WMD(24h) = 0.08, 95% CI −0.14 to −0.02; WMD(48h) = 0.09, 95% CI −0.11 to −0.07; all P < .05), and less postoperative tramadol consumption (WMD(0–24h) = −102.59 mg, 95% CI −149.68 to −55.49; WMD(0–48h) = −152.91 mg, 95% CI −259.93 to −45.89; all P < .05). With regard to safety, there was a significant difference between DEX-tramadol and tramadol for PCIA in terms of the incidence of postoperative nausea and vomiting, dizziness, chills, and restlessness (all P < .05). CONCLUSION: According to the domestic evidence, this systematic review and meta-analysis suggests that DEX-tramadol PCIA is superior to tramadol in terms of analgesic efficacy and safety for Chinese surgical patients. However, because of some clear limitations (sample size and heterogeneity), these results should be interpreted with caution. Further large-scale and well-designed studies are needed to summarize and analyze the data to draw a more convincing conclusion.