Our study aims to recruit pediatric patients receiving caudal epidural blocks as a complement to general anesthesia and for postoperative analgesia. Through a randomized allocation, we will administer the caudal injection with either a biplane ultrasound-guided approach or the single-plane ultrasound-guided technique. The assessment will encompass accuracy metrics, such as the first puncture success rate and number of needle redirections, and the efficiency indicators, including the time from initial probe placement on the skin to successful injection, the time to first postoperative analgesics use, and PACU (post anesthesia care unit) pain score. Safety evaluation will be conducted, encompassing adverse events from the commencement of the caudal block procedure until discharge. We will also conduct post-discharge follow-up phone calls to evaluate patients' experience after discharge.
