Efficacy of ultrasound-guided pudendal nerve block for labor analgesia and perineal protection

Abstract

Objective To investigate the efficacy of ultrasound-guided pudendal nerve block in labor analgesia and its effect for perineal protection. Methods Eighty primiparas undergoing vaginal delivery with pudendal nerve block between July and December, 2017 in our center were randomized into 2 groups, in which pudendal nerve block was performed under ultrasound guidance (n=40) or by blind exploration (n=40). The articulation of the anatomical structures of the perineal nerve displayed by ultrasound was evaluated. The Visual Analog Scale (VAS) scores in the second and third stages of labor, perineal protection, instrument-assisted delivery rate, and complications related with perineal nerve block were compared between the 2 groups. Results The articulation of the anatomical structures of the perineum nerve was excellent in 95% of the patients in the ultrasound group. Compared with the scores before analgesia, the VAS scores during labor were significantly reduced in both groups (P 0.05). Conclusion Labor analgesia with ultrasound-guided pudendal nerve block during the second stage of labor provides more effective analgesia and perineal protection and reduces the incidence of local hematoma to promote the recovery of primiparas.

Keywords

• ultrasound guidance
• pudendal nerve block
• labor analgesia