Intrathecal bupivacaine-fentanyl vs. bupivacainedexmedetomidine for cesarean section: a randomized controlled trial

Background & objectives: Spinal anesthesia is the preferred technique for obstetric patients as it is economical, simple to perform, has a rapid onset and provides complete muscle relaxation. A variety of adjuvants have been used to enhance or prolong its effects. We compared the effects of dexmedetomidine and fentanyl on the onset and recovery times of sensory and motor blockade as well as on hemodynamics, postoperative complications and duration of postoperative analgesia in parturients undergoing lower segment cesarean section (LSCS). Methodology: It was a prospective, double blind, randomized controlled trial. Sixty healthy parturients having cesarean delivery under spinal anesthesia were randomly divided into two equal groups. Group BD was given 10 mg bupivacaine plus 5 mu g of dexmedetomidine and Group BF was given 10 mg bupivacaine plus 10 mu g of fentanyl. Parturients was then observed for the onset and recovery times of sensorimotor blockade, hemodynamics, postoperative complications and postoperative analgesia. Results: There was no statistically significant difference in the onset of sensorimotor block between the groups. The time to complete sensory and motor recovery was significantly prolonged in Group BD (P = 0.01 and P = 0.0001 respectively) as compared to Group BF. Both groups did not show significant differences in hemodynamic changes, but there was a reduction in systolic and diastolic blood pressures = 20% from baseline intraoperative. The VAS at 3 and 4 h postoperatively in the Group BD was significantly lower (P = 0.02 and P = 0.01 respectively). The incidence of complications was found comparable in two groups, except incidence of hypotension and nausea was more in the Group BD compared to Group BF (P = 0.006 and 0.002 respectively). Conclusion: Although intrathecal dexmedetomidine prolongs the duration of sensory block, with comparable hemodynamic changes and good postoperative analgesia, prolonged motor block due to it, compared to intrathecal fentanyl, is not a desirable outcome particularly in short duration surgeries like LSCS, which can increase discharge time from post anesthesia care unit (PACU) to the ward.