Real‐time vs. pre‐procedural ultrasound guidance for lower thoracic epidural puncture: a randomised controlled trial

INTRODUCTION: Ultrasound-guided neuraxial anaesthesia has gained increasing attention because it may improve procedural success and safety. Lower thoracic epidural anaesthesia provides effective postoperative analgesia and is used widely in patients undergoing abdominal surgery. However, studies evaluating lower thoracic epidural puncture remain limited, and whether real-time or pre-procedural ultrasound guidance provides superior technical performance remains unclear. Therefore, we aimed to compare real-time and pre-procedural ultrasound-guided techniques in achieving first-pass success in lower thoracic epidural puncture. METHODS: We enrolled patients scheduled to undergo abdominal surgery requiring thoracic epidural anaesthesia. Patients were allocated randomly to real-time or pre-procedural ultrasound groups. In both groups, a preliminary scan was performed to identify and mark the target intervertebral level before needle insertion. In patients allocated to the real-time group, continuous in-plane ultrasound guidance was maintained throughout needle advancement. The primary outcome was first-pass success rate. Secondary outcomes included procedure time; number of passes; and number of punctures. RESULTS: In total, 64 patients were included in the final analysis. Patients allocated to the pre-procedural ultrasound group had a significantly lower first-pass success rate compared with the real-time ultrasound group (15/32 (47%) vs. 26/32 (81%), p = 0.008). In addition, fewer passes and punctures were required in patients allocated to the real-time group. Procedure time did not differ significantly between groups. DISCUSSION: Real-time ultrasound guidance significantly improved first-pass success compared with pre-procedural ultrasound guidance. These findings support the use of real-time ultrasound guidance to improve procedural success and technical performance during lower thoracic epidural puncture.