Efficacy of "over iliac crest method" for ultrasound-guided posterior lumbar plexus block: a comparison with manual palpation and sagittal positioning

Abstract

Objective To evaluate the efficacy of over iliac crest for ultrasound-guided posterior lumbar plexus block by comparing with manual palpation and sagittal positioning. Methods A total of 75 patients, aged 25-64 yr, weighing 42-90 kg, with body mass index of 17-32 kg/cm2, of American Society of Anesthesiologists physical status Ⅰ-Ⅲ, scheduled for elective lower extremity surgery under ultrasound-guided posterior lumbar plexus block combined with parasacral sciatic nerve block, were divided into 3 groups (n=25 each) using a random number table method: manual palpation group (group M), sagittal positioning group (group S) and over iliac crest group (group O). Patients received ultrasound-guided posterior lumbar plexus block with in-plane technique using the corresponding positioning method in M, S and O groups.Successful blockade of each level was recorded at 30 min after injection.Time to determine the lumbar intervertebral space, puncture time for lumbar plexus block, the requirement for adjuvant drugs and block efficacy were recorded.The development of complications related to puncture and nerve block was also recorded. Results Compared with group M, the success rates of blockade at levels L1 and L2 were significantly increased, the success rates of blockade at levels L4 and L5 were decreased (P 0.05), the time to determine the lumbar intervertebral space was prolonged, and the requirement for adjuvant drugs was decreased during surgery in O and S groups, and the efficacy of block was significantly enhanced in group O (P 0.05). There was no significant difference in the puncture time for lumbar plexus block between the three groups (P>0.05). Complications related to puncture and nerve block were not found in three groups. Conclusion Over iliac crest provides higher success rate and better efficacy than manual palpation and sagittal positioning when used for lumbar plexus block. Key words: Lumbosacral plexus; Nerve block; Ilium