Comparative study between ultrasound-guided pudendal nerve block and caudal epidural block anesthesia in children undergoing hypospadias surgery

Background The aim of the study is to compare the effectiveness and safety of ultrasound-guided pudendal nerve block versus caudal epidural block as a part of multimodal analgesia in children undergoing hypospadias surgery. In this prospective, single-blinded study, 50 patients were randomized into 2 groups (25 each group) either receiving ultrasound-guided pudendal nerve block group A or caudal epidural block group B. In the pudendal nerve block group, patients were injected with 0.3 mL/kg 0.25% bupivacaine and 1 ug/kg fentanyl. In the caudal epidural group, patients were injected with 1 mL/kg 0.25% bupivacaine and 1 ug/kg fentanyl. Consumption of paracetamol was assessed during the first 24 h postoperatively. The “objective pain scale” done by Hannalah and Broadman was used to assess postoperative pain. Results This prospective randomized controlled single-blind clinical study was performed on total (50) ASA status I or II patients, of age 3 to 6 years scheduled for hypospadias surgery. For the primary outcome, there was no statistically significant difference found between the two studied groups regarding objective pain score at arrival to PACU with p value = 1.000 while there was a statistically significant increase in pain score in group B than group A at 6 h and 12 h with p value = 0.017 and 0.003, respectively. Also, no statistically significant difference found between the two groups after 18 h with p value = 0.238 may be due to receiving acetaminophen dose in group B. Finally there was a statistically significant increase found in objective pain score in group B at 24 h than group A with p value = 0.015. And there was a statistically significant increase in time to first analgesia in group A than group B with p value < 0.001 while there was a statistically significant increase in total dose of acetaminophen in group B than group A with p value < 0.001. Conclusion Both ultrasound-guided pudendal block and caudal epidural block are effective and safe methods for postoperative analgesia for children undergoing hypospadias surgery but ultrasound-guided pudendal block gives more postoperative pain control.