Effects of the Sufentanil and Dexmedetomidine Combination on Spinal Anesthesia in Patients Undergoing Lower Abdominal or Lower Extremity Surgery: A Double-Blind Randomized Controlled Trial

BACKGROUND: Intrathecal additive drugs are becoming increasingly common in anesthesia practice. We aimed to evaluate the additive effects of dexmedetomidine on spinal anesthesia with sufentanil in patients undergoing lower abdominal or lower limb surgery. METHODS: This double-blind randomized controlled trial was performed in Mashhad, Iran, between 2017 and 2018. Sixty patients undergoing lower abdominal or lower limb surgery were randomly divided to receive 15 mg of bupivacaine and 3 μg of sufentanil (control group; n=30) or 15 mg of bupivacaine, 3 μg of sufentanil, and 10 μg of dexmedetomidine (intervention group; n=30). Outcomes, comprised of the onset and regression of sensory and motor blocks, the duration of analgesia, analgesic use, hemodynamic parameters, and side effects, were assessed. The data were analyzed in the SPSS software (version 22), using different statistical tests. A P value of less than 0.05 was considered significant. RESULTS: The times of sensory and motor blocks reaching T10 and Bromage 3, respectively, were significantly shorter, while the times of sensory and motor regressions to S1 and Bromage 0, correspondingly, were significantly longer in the intervention group than in the control group (P<0.001). Both the frequency (P=0.006) and the dose (P<0.001) of postoperative analgesic use were significantly lower, and the duration of analgesia was significantly longer in the intervention group (P<0.001). The frequency of side effects and changes in hemodynamic parameters had no significant differences between the groups. CONCLUSION: The sufentanil and dexmedetomidine combination in spinal anesthesia caused the earlier onset and later regression of sensory and motor blocks, longer postoperative analgesia, and lower analgesic use without significant side effects or hemodynamic changes, which appears to be due to the combined effects of sufentanil and dexmedetomidine. Trial Registration Number: IRCT2017082833680N3.