Low dose of dexmedetomidine as an adjuvant to bupivacaine in cesarean surgery provides better intraoperative somato-visceral sensory block characteristics and postoperative analgesia.

Object: In this study, we aimed to investigate the beneficial effects of dexmedetomidine on somato-visceral sensory block characteristcs, postoperative analgesia and stress response of intrathecal bupivacaine administration in women undergoing cesarean section, and to find out which dose is better.

Methods: Sixty parturients with the American Society of Anesthesiologists (ASA) physical status I or II were anesthetized with intrathecal bupivacaine(10mg) alone or in combination with dexmedetomidine (3 μg and 5 μg) to undergo cesarean section. The anesthetic parameters, postoperative analgesia and stress responses were monitored.

Results: Co-administration of dexmedetomidine(3 μg and 5 μg) prolonged the duration of motor and sensory block compared with bupivacaine(10mg) alone. Less supplemental dose of lidocaine and fentanyl were required in dexmedetomidine(3 μg and 5 μg) co-administration groups. Visceral traction response and abdominal muscle relaxation in operation were better in dexmedetomidine(3 μg and 5 μg) co-administration groups. No difference in haemodynamics was detected among groups. There was no significant difference in Apgar scores, neonatal umbilical pH, oxygen pressure, carbon dioxide pressure and lactate level among groups. Postoperative plasma IL-6 and cortisol levels were lower in dexmedetomidine(3 μg and 5 μg) co-administration groups. At 6 hour after operation the visual analogue scale (VAS) was smaller in dexmedetomidine(3 μg and 5 μg) co-administration groups. The uterine contraction pain at 6 and 12 hour after operation and supplemental analgesics had no difference across three groups. No difference of side effects(shivering, nausea and vomiting, itching), the first anal aerofluxus time and intraoperation tramadol dose were detected among the three groups.

Conclusion: The use of dexmedetomidine especially at the dose of 3μg as an adjuvant to bupivacaine in cesarean surgery provides better intraoperative somato-visceral sensory block characteristcs and postoperative analgesia, which produced no influence on Apgar scores, side effects and stress response.