Optimizing epidural fentanyl loading dose for early labor pain

Objective: Sufficient sensory blockade between L1 and T10 is required to relieve visceral pain during early labor. We examined whether the addition of fentanyl to a loading dose of 0.0625% bupivacaine could provide dose-dependent analgesic effects on early-stage labor pain. Methods: Sixty parturients who requested epidural analgesia for labor pain were enrolled and randomly allocated to one of three groups. Group A (n=20) received 10 mL of 0.0625% epidural bupivacaine as a loading dose alone. Group B (n=20) received the same bupivacaine loading dose in combination with 2 μg/mL fentanyl. Group C (n=20) received the same loading bupivacaine dose plus 4 μg/mL fentanyl. All patients received diluted bupivacaine plus 2 μg/mL fentanyl at a rate of 10 mL/hr as a maintenance dose. Fifteen minutes later, we recorded the highest cephalic and lowest caudal anesthetized dermatomes, side effects, and the number of patients who asked for supplemental analgesia. Results: The highest anesthetized cephalic dermatome was at the level of T12 (T9-L1) in Group A, T9 (T8-T12) in Group B and T7 (T5-T9) in Group C (p