Comparison of the ultrasonography-guided technique and conventional anatomical landmark technique for localization of epidural space during epidural block

Abstract

Background and aims Anatomical landmarks-based level confirmation and loss of resistance-based space confirmation is a standard method for epidural block but is a blind procedure. Recently, the use of ultrasonography (USG) guidance during central neuraxial blocks to preview the anatomy before needle puncture has started. We carried out a study to find whether USG-guided technique is superior than landmark guided for epidural space localization. Patients and methods This randomized prospective, open-label study included 76 patients aged 40 to 65 years, American Society of Anesthesiologist physical status I–III undergoing infraumbilical surgeries, divided in two groups. In group 1, anatomical landmark-guided technique and in group 2, preprocedural USG scan was used for puncture site determination. We evaluated the time taken to insert an epidural needle; number of attempts, number of times the cortexes of bone touched by needle, ultrasound visibility score, distance between skin to ligamentum flavum, correlation between actual needle depth and ultrasound-measured depth. Results Mean time taken for insertion of epidural needle in group 1 was 72.21±45 s and in group 2 was 54.82±40.87 s (P=0.027). Epidural space was located in the first attempt in 71.15% individuals of group 1 and 92.1% individuals of group 2. The Pearson’s correlation coefficient between the USG-measured distance between skin to ligamentum flavum and the actual depth of needle mark was significant. Conclusion The USG-guided epidural space localization reduces time to insert epidural needle and number of attempts for localization of epidural space. There is a strong correlation between the USG-measured depth and the actual needle depth.