Effects of epidural fentanyl on speed and quality of block for emergency cesarean section in extending continuous epidural labor analgesia using ropivacaine and fentanyl.

We performed a prospective, randomized, and double-blind study comparing the top-up effects of 2% lidocaine/100 microg fentanyl/epinephrine (n=31) and 2% lidocaine/saline/epinephrine (n=30) when extending an epidural labor analgesia using low-dose ropivacaine and fentanyl. Survival analysis for the sensory blocks to the T4 level showed no statistically significant differences in onset time to T4 between the 2 groups. Onset times (min) to T4-sensory blocks for cold and pinprick were not different between the two groups. However, median maximum sensory level in the lidocaine-fentanyl group (T1 for cold and T2 for pinprick) was significantly higher than that in the lidocaine-saline group (T3 and T4, respectively). The lidocaine-fentanyl group exhibited less visceral pain (6.5% vs. 36.7%), less supplementation of lidocaine (6.5% vs. 43.3%), and less nausea (6.5% vs. 26.7%) compared with the lidocaine-saline group during the intraoperative period. It is concluded that adding fentanyl to 2% lidocaine does not speed up the onset of the block when the onset is tested with cold or sharp pinprick but improves the quality of analgesia with fewer side effects in emergency top-up for cesarean section.