Subarachnoid Analgesia in Advanced Labor: A Comparison of Subarachnoid Analgesia and Pudendal Block in Advanced Labor: Analgesic Quality and Obstetric Outcome

Abstract

Pain control during labor is a primary objective of antalgic therapy. The use of the peridural as an elective procedure for labor analgesia is now corroborated by the international scientific community. Sometimes a combined spinal-peridural procedure is used together with the intrathecal administration of opioids to also cover the first stage of labor. Unfortunately, patients and/or gynecologists often request analgesia in a late stage of labor. The aim of our study was to evaluate the possibility of using a subarachnoid block alone for labor analgesia when this is requested at a late stage, that is, in advanced labor with cervical dilation greater than 7 cm. After approval by our ethics committee and the written and informed consent of the patients, 111 women were enrolled in this study and randomly divided into two groups. The first group (Group S: 55 patients) received a subarachnoid block with 2.5 mg hyperbaric bupivacaine + 25 mug fentanyl + 1 mL 10% glucose. A pudendal nerve block with 7 mL 2% mepivacaine in each side was administered to the second group (Group P: 56 patients). In both groups, careful maternal-fetal monitoring was conducted, and pain was scored on a numerical scale from 0 to 4, 10 minutes after placement of the block (time [T] 0), at delivery (T1), and at episiorrhaphy (T2). In all patients, we recorded any side effects, the Apgar score at birth and after 5 minutes, the administration of other analgesic and/or sedative drugs, the degree of satisfaction, and the time of hospitalization after delivery. Evaluations were performed by anesthesiologists unaware of patients' treatment group. The duration of spinal analgesia was considered to be the time from injection of study drugs to the time of the patient's first request for additional analgesia. In no cases were there any side effects worthy of note, and hospitalization never exceeded 72 hours. The Apgar score was always between 7 and 10. All except one of the women in Group S were satisfied or more than satisfied with their pain management, whereas 50 women in Group P expressed only moderate satisfaction or dissatisfaction (P < 0.0001). In most patients in Group S, complete analgesia was obtained. In Group P, however, 10 minutes after placement of the pudendal nerve block, 40 patients reported no improvement in pain symptomatology during contractions and only 16 reported less painful contractions (P < 0.0001). The duration of spinal analgesia (128 +/- 38 minutes) was enough in most cases for delivery to be completed. These results suggest that low-dose bupivacaine-fentanyl spinal analgesia represents an important option for pain relief in late labor, not the least because the procedure does not upset the dynamics of delivery or alter vital parameters and is welcomed by women in labor who are still able to collaborate actively in the birth of their baby.