Abstract :
Continuous extradural infusion of dilute local anesthetics is widely regarded as the most effective analgesic strategy for labor pain. However, this low dose extradural infusion strategy often results in recurrence of pain in late stage of labor.Although requests from patients to alleviate breakthrough pain are common, no one knows the most effective strategy for pain management in this stage of labor. Opioids are often added to improve analgesia, but opioids have disadvantages. Methods: 100 healthy parturients who have labor extradural analgesia in place were studied. When they were in late first stage or second stage of labor and requesting analgesia for breakthrough pain, they were allocated randomly into two equal groups to receive 8 ml of a solution containing 10 mg bupivacaine and 75 Ug of either fentanyl or clonidine.Maternal vital parameters were measured. Analgesia was evaluated during 25 min using a visual analogue scale (VAS). Evaluation of side-effects included pruritus, vomiting, and sedation. Neonatal weight and Apgar scores were recorded. Results: The reduction in VAS was greater at all times in the bupivacaine-clonidine group. Analgesia was associated with a significant decrease in MAP in the bupivacaine-clonidine group between 20 and 90 min in comparison to bupivacaine-fentanyl group. After 10 min, maternal heart rate in the bupivacaine-clonidine group was significantly lower than the corresponding heart rate of bupivacaine-fentanyl group. The incidence of side effects was significantly less in the bupivacaine-clonidine group compared with the bupivacaine-fentanyl group. There were no differences among groups for neonatal Apgar scores. Conclusion: combination of bupivacaine and clonidine provides better analgesic than fentanyl added to bupivacaine for breakthrough pain in advanced vaginal delivery.
