Ultrasound-guided midline versus paramedian approach for combined spinal–epidural anesthesia: A randomized controlled study

Abstract Background and Aims: Neuraxial ultrasound (USG) can increase the success rate of neuraxial blocks, such as combined spinal–epidural (CSE). The two commonly practiced approaches for CSE are midline and paramedian. However, only a few studies have compared the USG-assisted midline and paramedian approaches. Therefore, we planned this study to evaluate and compare the efficacy of USG-assisted paramedian and midline approach for CSE anesthesia. Material and Methods: Eighty american society of anesthesiologists (ASA) grade I/II patients undergoing elective orthopedic surgery under CSE anesthesia were enrolled. Patients were allocated to Group M (midline) or Group P (paramedian group) for the USG-assisted CSE block. The primary outcome was the first-pass success rate. The secondary outcomes were the second-pass success rate, the number of needle insertions, the number of needle redirections, image quality score, scan time, and procedure time. Results: The first-pass success rate was statistically comparable for Groups P and M (26.31% vs. 34.21%; P = 0.469). The number of needle insertions in Group P was statistically lower than in Group M ( P = 0.021), and the number of redirections was statistically comparable between the two groups ( P = 0.607). The image quality score was comparable for both groups. The scan time required for USG was statistically less in Group P than in Group M (224 sec vs 183 sec, P < 0.0001). The procedure time was, however, statistically comparable between the two groups ( P = 0.297). Conclusions: USG-assisted midline and paramedian approaches for CSE have comparable first-needle pass success rates.