Ultrasonography of the lumbar spine for neuraxial and lumbar plexus blocks.

PURPOSE OF REVIEW Ultrasonography of the spine has evolved into a well described technique that can be applied to facilitate neuraxial and lumbar plexus blockade. RECENT FINDINGS There is increasing evidence for the clinical benefits of ultrasound imaging prior to administration of neuraxial blockade. Recent randomized controlled trials have shown that efficacy of epidural analgesia is improved, and the technical difficulty of spinal and epidural anaesthesia is reduced. Ultrasound imaging may also permit more accurate prediction of the depth to epidural and intrathecal spaces and more accurate identification of intervertebral levels. The use of ultrasound in lumbar plexus blockade has been described in the context of both preprocedural imaging and real-time needle guidance; however, its clinical benefit in this setting has not yet been clearly established. SUMMARY Preprocedural ultrasound imaging of the spine may reduce the technical difficulty of neuraxial blockade and also improve clinical efficacy. Similar benefits are expected in the setting of lumbar plexus blockade although there is currently no evidence to confirm this. Real-time ultrasound-guided neuraxial and lumbar plexus blockade are challenging techniques that need further validation.