Intrathecal Fentanyl versus Dexmedetomedine as Adjuvants to Bupivacaine for Cesarean Section

Background: Intrathecal α2 agonists prolong the duration of action of local anesthetics and reduce the required dose. Dexmedetomidine is an α2 receptor agonist, and its α2/α1 selectivity is eight times higher than that of clonidine Aim of the work:  This study aimed to determine the effect of adding dexmedetomidine or fentanyl to intrathecal bupivacaine on the onset time, duration, and intensity of motor and sensory blocks as the primary outcome and postoperative analgesia, sedation, and incidence of side effects as a secondary outcome in cesarean section. Patients and methods: The study was carried out on 40 adults full-term pregnant female submitted for elective cesarean section were randomly classified into two equal groups, twenty patients each: Group [D]: Patients received intrathecally bupivacaine and dexmedetomidine. Group [F]: Patients received intrathecally bupivacaine and fentanyl. Results: Sensory and motor block onset times were shorter in Group D than in Group F. The regression of the sensory block to S1 dermatome and Bromage 0 were longer in Group D than in Group F. The two-dermatome regression time was longer in Group D than in Group F. There was a statistically significant decrease in group F regarding systolic, diastolic, mean arterial blood pressure, and heart rate than in group D. The postoperative analgesic effect time was longer in group D than in group F. Neonatal outcome was normal in all groups Conclusion: We concluded that adding intrathecal dexmedetomidine to bupivacaine for spinal anesthesia synergistically increase block duration and shortens sensory and motor block onset time with better postoperative analgesia without any significant adverse effects.