The efficacy and safety of intrathecal dexmedetomidine for parturients undergoing cesarean section: a double-blind randomized controlled trial

BACKGROUND: The efficacy and safety of spinal anesthesia by intrathecal dexmedetomidine (DEX) for parturients undergoing cesarean section are still lack of evidence. This aim of our study was to evaluate the efficacy and safety of intrathecal DEX for parturients undergoing cesarean section to provide more data evidence for intrathecal applications. METHODS: Three hundred parturients undergoing cesarean section under spinal anesthesia were randomly assigned into three groups: group B: 9.0 mg (1.2 ml) of 0.75% bupivacaine with saline (1 ml); group FB: 9.0 mg (1.2 ml) of 0.75% bupivacaine with 20 μg of fentanyl (1 ml); group DB: 9.0 mg (1.2 ml) of 0.75% bupivacaine with 5 μg of DEX (1 ml). Intraoperative block characteristics, parturients’ postoperative quality of recovery, maternal and neonatal outcomes and the plasma concentration of DEX were measured. All parturients were followed up for 30 days to determine whether nerve injury occurred. RESULTS: Compared with group B, the duration of sensory block in group FB and group DB were significantly prolonged (108.4 min [95% Confidence Interval (CI) = 104.6–112.3] in group B, and 122.0 min [95% CI = 116.8–127.3] in group FB, 148.2 min [95% CI = 145.3–151.1] in group DB). The overall score of quality recovery in group DB (71.6 [95% CI = 71.0–72.2]) was significantly higher than that in group FB (61.5 [95% CI = 60.8–62.2]) and group B (61.7 [95% CI = 61.0–62.4]). There was no statistically significant difference among the three groups for PH, PaO(2), and PaCO(2) of newborn. The plasma concentration of DEX in umbilical artery and umbilical vein was low and cannot be detected. The 30-days follow-up of parturients did not show any new onset of back, buttock or leg pain or paresthesia. CONCLUSIONS: DEX is a potential local anesthetic adjuvant that the intrathecal combination of 5 μg DEX can safely exhibit a facilitatory block effect and improve parturients’ recovery quality. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Registration number # ChiCTR1900022019; Date of Registration on March 20th, 2019).