Assessment the effect of fentanyl and dexmedetomidine as adjuvant to epidural bupivacaine in parturients undergoing normal labor

Background: Dexmedetomidine acts on the pre and post-synaptic sympathetic nerve terminal and central nervous system. It decreases the sympathetic outflow and norepinephrine release; therefore it leads to sedation, analgesia and hemodynamic effects. The aim of the study was to compare the effect of fentanyl and dexmedetomidine as adjuvant to epidural bupivacaine in parturients undergoing normal labor. Materials and methods: The study included 170 parturients scheduled for epidural anesthesia for labor. The cases were classified randomly (by simple randomization) into two groups (n=85): Group D: The patients received 13 ml of 0.25% bupivacaine and 1μg/kg dexmedetomidine diluted in 2 ml saline. Group F: The patients received 13 ml of 0.25% bupivacaine and 1μg/kg fentanyl diluted in 2 ml saline. Results: The dexmedetomidine shortened the onset and prolonged the duration of analgesia compared to fentanyl (p<0.05). Dexmedetomidine was associated with an increased incidence of maternal hypotension, bradycardia, motor block, and dry mouth (p<0.05), while the epidural fentanyl was associated with an increased incidence of maternal pruritus, nausea and vomiting, and respiratory depression (p<0.05). The incidence of shivering was lower in the dexmedetomidine group compared to fentanyl group (p=0.003). Conclusions: The epidural dexmedetomidine has many advantages over the fentanyl, where it fastens the onset, prolongs the duration of analgesia, decreases the doses of bupivacaine and the incidence of pruritus, respiratory depression, nausea and vomiting. Also, it is associated with some disadvantages such as maternal hypotension, bradycardia and motor block.