Ultrasound-guided neuraxial block

Recent ultrasound-guided technique has provided a smooth and accurate neuraxial block compared to the classic anatomical landmark technique. This review mainly focuses on the basic technique of ultrasonography for neuraxial block and specific techniques for increasing successful rates of neuraxial puncture and outcome of neuraxial block in various types of patients. Identification of the structure of the spine and lumbar and lower thoracic epidural space in normal adult patients is the basic technique of ultrasound-guided neuraxial block. In most cases, ultrasound guidance can provide location of the epidural space, distance between the skin to dura mater and angle of the needle manipulation in short axial view and longitudinal view. Especially, the paramedian longitudinal oblique view is the most convenient image, which usually provides sufficient information to perform accurate neuraxial block. This review summarizes technical keys and the basics of ultrasound-guided lumbar neuraxial block, caudal block and thoracic epidural block and neuraxial block for obese, pregnant, pediatric, scoliosis or elderly patients. Therefore, recent advances of real-time ultrasound-guided neuraxial block and ultrasound-guided unilateral epidural block are also introduced. Ultrasonography facilitates neuraxial block in various types of patients. Anesthesiologists are expected to understand the anatomy of the spine and to be able to handle the ultrasonography equipment for performing a safer and easier approach.