Comparative Study of Fentanyl vs Dexmedetomidine as Adjuvants to Intrathecal Bupivacaine in Cesarean Section: A Randomized, Double-Blind Clinical Trial

Purpose: Effective postoperative analgesia is essential in cesarean section. This study aimed to compare postoperative analgesia and hemodynamic changes after intrathecal use of fentanyl or dexmedetomidine combined with bupivacaine. Patients and Methods: This study involved 110 pregnant women with ASA I and II and gestational age >= 37 weeks who were candidates for elective cesarean section. They were randomly divided into two groups of 55; Group B-D received 10 mg bupivacaine (0.5%) + 5 mu g dexmedetomidine and Group B-F received 10 mg bupivacaine (0.5%) + 25 mu g fentanyl, intrathecally. The onset of block, duration of analgesia, the score of pain intensity, hemodynamic changes, Apgar scores, and any adverse events were evaluated. P-value < 0.05 was considered statistically significant. Results: Patients in two groups were similar in terms of demographic characteristics and ASA classification. Duration of analgesia in the B-D group was significantly longer than B-F group (428.64 +/- 73.39 vs 273.18 +/- 61.91 min; P< 0.001). The score of pain intensity during recovery time in the B-D group was significantly lower than that of B-F group (0.33 +/- 0.84 vs 0.51 +/- 0.57 min; P=0.004). The onset of block was also faster in the B-D group than B-F group (98.27 +/- 35.95 vs 110.45 +/- 37.69 seconds; P=0.036). The two groups did not show significant differences in hemodynamic changes and other variables (P> 0.05). Conclusion: Compared with fentanyl, it seems that adding 5 mu g dexmedetomidine to bupivacaine has a better effect on postoperative pain management in cesarean section under spinal anesthesia.