Comparison of dexmedetomidine and opioids as local anesthetic adjuvants in patient controlled epidural analgesia: a meta-analysis

Background: Data on the efficacy and incidence of adverse effects associated with dexmedetomidine (DEX) as a local anesthetic adjuvant for patient-controlled epidural analgesia (PCEA) are inconclusive. This meta-analysis assessed the efficacy and risks of DEX for PCEA using opioids as a reference. Methods: Two researchers independently searched PubMed, Embase, Cochrane Library, and China Biology Medicine for randomized controlled trials comparing DEX and opioids as local anesthetic adjuvants in PCEA. Results: In total, 636 patients from seven studies were included in this meta-analysis. Postoperative patients who received DEX had lower visual analog scale (VAS) scores than those who received opioids at 4-8 h (mean difference [MD]: 0.61, 95% CI [0.45, 0.76], P < 0.001, I-2 = 0%), 12 h (MD: 0.85, 95% CI [0.61, 1.09], P < 0.001, I-2 = 0%), 24 h (MD: 0.59, 95% CI [0.06, 1.12], P = 0.030, I-2 = 82%), and 48 h (MD: 0.54, 95% CI [0.05, 1.02], P = 0.030, I-2 = 91%). Additionally, patients who received DEX had a lower incidence of itching (odds ratio [OR]: 2.86, 95% CI [1.18, 6.95], P = 0.020, I-2 = 0%) and nausea and vomiting (OR: 6.83, 95% CI [3.63, 12.84], P < 0.001, I-2 = 24%). In labor analgesia, no significant differences in neonatal (pH and PaO2 of cord blood, fetal heart rate) or maternal outcomes (duration of labor stage, mode of delivery) were found between the DEX and opioid groups. Conclusions: Compared with opioids, using DEX as a local anesthetic adjuvant in PCEA improved postoperative analgesia and reduced the incidence of itching and nausea and vomiting without increasing the incidence of adverse events.