The effect of adding dexmedetomidine or dexamethasone to bupivacaine-fentanyl mixture in spinal anesthesia for cesarean section.

Background and aims: Many strategies are available to prevent spinal-induced hypotension in cesarean section, especially the use of a low dose of spinal anesthesia combined with adjuvants. This study investigated the effect of adding either dexmedetomidine or dexamethasone to the intrathecal bupivacaine-fentanyl mixture on the postoperative analgesia duration, after elective cesarean section.

Material and methods: This prospective, randomized, double-blind study was conducted on 90 full-term parturients undergoing elective cesarean section, who were randomly distributed into three groups. They all received spinal anesthesia with the bupivacaine-fentanyl mixture (2.5 ml), in addition to 0.5 ml normal saline (control group), 5 μg dexmedetomidine dissolved in 0.5 ml normal saline (dexmedetomidine group), or 2 mg dexamethasone (dexamethasone group). The time to the first request of morphine rescue analgesia was recorded, in addition to the total dose of morphine consumed in the first 24 h after surgery, the postoperative numerical rating score (NRS), and maternal and fetal outcomes.

Results: As compared to the control group and the dexamethasone group, the use of dexmedetomidine as an additive to the bupivacaine-fentanyl mixture significantly prolonged the time to the first request of rescue analgesia, decreased postoperative morphine consumption, and decreased the pain score 4 and 6 h after surgery. There was an insignificant difference between the control and dexamethasone groups.

Conclusion: The use of dexmedetomidine as an additive to bupivacaine-fentanyl mixture in spinal anesthesia for cesarean section prolonged the postoperative analgesia and decreased the postoperative opioid consumption in comparison to the addition of dexamethasone or normal saline.