Effect of adding intrathecal dexmedetomidine as an adjuvant to hyperbaric bupivacaine for elective cesarean section

Background & Aims: Cesarean section performed under subarachnoid block is often accompanied by visceral pain. Hence, various adjuvants have been tried to address this problem and to provide prolonged postoperative analgesia. Highly selective alpha 2-agonist dexmedetomidine is increasingly used as an intrathecal adjuvant. The study was designed to evaluate dexmedetomidine 5 mu g as adjuvant to intrathecal hyperbaric 0.5% bupivacaine 9 mg in cesarean sections with respect to block characteristics, sedation and neonatal APGAR scores. Settings and Design: A prospective, randomized, double blinded, controlled study Methodology: 60 parturients undergoing elective lower segment cesarean section were assigned to 2 groups (n=30) to receive either 0.5% hyperbaric bupivacaine 9 mg with dexmedetomidine 5 mu g (Group D) or 0.5% hyperbaric bupivacaine 9 mg with saline (Group C). Block characteristics, hemodynamic parameters, sedation scores and neonatal APGAR scores were recorded. Data obtained were compiled and analyzed with appropriate tests. A p-value of < 0.05 was considered significant. Results: Onset of sensory and motor block were significantly faster in Group D (45 and 43 sec) compared to Group C (68 and 67 sec). Time for two segment sensory regression, duration of sensory and motor block was significantly prolonged in Group D compared to Group C (140 vs 44, 364 vs 126 and 341 vs 113 min). Time for first analgesic request was significantly prolonged in Group D compared to Group C (420 and 69 min). There was no significant difference in hemodynamic parameters, sedation and neonatal APGAR scores between the groups. Conclusions: The addition of 5 mu g dexmedetomidine as an intrathecal adjuvant to bupivacaine for cesarean section hastens and prolongs sensory and motor block and provides better perioperative analgesia without significant maternal and neonatal adverse effects.