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

Abstract

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. 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. 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. 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.