摘要
A nerve stimulation-guided lumbar plexus block is a well-established technique.It is not clear whether ultrasound guidance has additional value for this deep block technique.This study aimed to examine whether ultrasound guidance using a paramedian transverse scan through the intertransverse space(PMTS-ITS)approach in combination with nerve stimulation reduces the onset time of a complete sensory block.Forty-four patients who were scheduled to undergo arthroscopic knee surgery with an ultrasound visibility score(UVS)of≥10 for the lumbar plexus were enrolled and randomly allocated to the ultrasound guidance with nerve stimulation group(group U-N)or nerve stimulation group(group N)in this prospective,randomized,parallel-group,active-controlled study.The primary outcome was the onset time of a complete sensory block.The results showed that the onset time of a complete sensory block to pinprick and cold was 10(10–40)min and 10(10–40)min in group U-N,respectively,and 30(10–40)min and 20(10–40)min in group N(P=0.005,P=0.004),respectively.The performance time was 658±87 s in group U-N and 528±97 s in group N(P<0.001).There was no(0%)patient who required 5 or more needle passes in group U-N and 6(27.3%)in group N(P=0.028).The block failure rate was 9.1%in group U-N and 31.8%in group N(P>0.05).In conclusion,ultrasound guidance using the PMTS-ITS approach in combination with nerve stimulation led to a faster onset of a complete sensory block than nerve stimulation alone for a lumbar plexus block in patients with a UVS≥10.Ultrasound guidance with nerve stimulation significantly decreased the number of patients who required 5 or more needle passes.
