Objective: To compare the clinical effects of intrathecal fentanyl with conventional epidural bupivacaine bolus before the same continuous epidural infusion for labor analgesia.
Material and Method: Fifty parturients in active labor were randomized to receive subarachnoid fentanyl 25 mcg as part of a combined spinal epidural analgesia (CSE) or bupivacaine 0.25% 10 ml incrementally into the epidural space in the epidural group. After that, 0.0625% bupivacaine with fentanyl 2 mcg/ml was infused via epidural catheter in all women at a rate of 12 ml/h. Verbal numeric pain scores (VNPS), onset time to pain relief, times of additional analgesia and other side effects were recorded.
Results: Mean (SD) onset time to the first pain free contraction was not significantly different (7.8 + 4.3 min in the CSE group, 10.2 + 5.1 min in epidural group, p = 0.085). Most of the patients in the CSE group required additional epidural bolus dose (80% compared to 48% in the Epidural group, p = 0.038). There was no difference in motor blockage at time of delivery or mode of delivery. Significantly more women in the CSE group had pruritus (68%VS none in the epidural group, p < 0.001), all had mild degree and did not require any treatment. There was no difference in other side effects.
Conclusion: Intrathecal fentanyl as part of CSE did not produce statistically a significant faster onset compared to epidural bupivacaine bolus. Most of the patients in the CSE group required epidural bolus after intrathecal fentanyl with a higher incidence of pruritus.

Keywords: Combined spinal epidural analgesia, CSE, Epidural analgesia, Labor, Obstetric