A comparison of intrathecal dexmedetomidine verses intrathecal fentanyl with epidural bupivacaine for combined spinal epidural labor analgesia

Context: Combined spinal epidural (CSE) analgesia technique is effective for labor analgesia and various concentrations of bupivacaine and lipophilic opioids like fentanyl have been studied. Dexmedetomidine is a highly selective alpha 2 adrenoreceptor agonist with analgesic properties and has been used intrathecally with bupivacaine for prolonged postoperative analgesia. Recent reviews have shown that it is highly lipophilic and does not cross placenta significantly. Aim: The aim of this study is to compare the duration and quality of analgesia, maternal and neonatal outcomes after CSE labor analgesia with intrathecal dexmedetomidine and intrathecal fentanyl followed by epidural bupivacaine. Settings and Design: A randomized observational study with 112 parturients in a tertiary care hospital. Materials and Methods: 112 parturients were randomly divided to two groups. Group D (n = 58) received dexmedetomidine 10 μg and group F (n = 54) received fentanyl 20 μg intrathecally for labor analgesia. The time of onset, time to maximum analgesia, duration and quality of analgesia were noted. Maternal parameters of heart rate, noninvasive blood pressure, motor block and side-effects of pruritus, nausea and vomiting were recorded. Neonatal outcome in terms of mode of delivery, neonatal APGAR score, time to first cry, need for resuscitation, umbilical cord blood pH, initiation of breast feeding, Neurologic and Adaptive Capacity Score at 24 h and exclusivity of breast feeding at 6 weeks were recorded. Results: Duration of analgesia was 160.54 ± 52.4 min with dexmedetomidine and 124.1 ± 46.93 min with fentanyl (P < 0.001). Visual analog score (VAS) recorded at maximal analgesia was significantly lesser in the fentanyl group compared to dexmedetomidine group, denoting a significantly deeper level of analgesia with fentanyl. However, all the mothers in the dexmedetomidine group achieved a VAS <3 and were satisfied with the quality of analgesia. About 74% patients in the fentanyl group experienced pruritus after intrathecal injection whereas none of the mothers in dexmedetomidine group experienced pruritus (P < 0.001). There were no significant differences in neonatal outcome between the two groups. Conclusion: 10 μg dexmedetomidine intrathecally provides a longer duration of analgesia with lesser incidence of pruritus compared to 20 μg fentanyl intrathecally for CSE labor analgesia with comparable neonatal side-effects