Ultrasound Imaging of the Spine for Central Neuraxial Blockade: a Technical Description and Evidence Update

Abstract

Purpose of Review This article describes the anatomy of the spine, relevant ultrasonographic views, and the techniques used to perform the neuraxial blocks using ultrasound imaging. Finally, we review the available evidence for the use of ultrasound imaging to perform neuraxial blocks. Recent Findings Central neuraxial blockade using traditional landmark palpation is a reliable technique to provide surgical anesthesia and postoperative analgesia. However, factors like obesity, spinal deformity, and previous spine surgery can make the procedure challenging. The use of ultrasound imaging has been shown to assist in these scenarios. Summary Preprocedural imaging minimizes the technical difficulty of spinal and epidural placement with fewer needle passes and skin punctures. It helps to accurately identify the midline, vertebral level, interlaminar space, and can predict the depth to the epidural and intrathecal spaces. By providing information about the best angle and direction of approach, in addition to the depth, ultrasound imaging allows planning an ideal trajectory for a successful block. These benefits are most noticeable when expert operators carry out the ultrasound examination and for patients with predicted difficult spinal anatomy. Recent evidence suggests that pre-procedural neuraxial ultrasound imaging may reduce complications such as vascular puncture, headache, and backache. Neuraxial ultrasound imaging should be in the skill set of every anesthesiologist who routinely performs lumbar or thoracic neuraxial blockade. We recommend using preprocedural neuraxial imaging routinely to acquire and maintain the imaging skills to enable success for challenging neuraxial procedures.

Evaluation of Lumbar Sonography as a Learning Aid for Performing Subarachnoid Block Using the Paramedian Approach by Medical Junior Resident Anaesthesiologists: A Randomized Controlled Trial

“…The present study was conducted to determine whether a preprocedural lumbar ultrasound scan can improve the success rate of the first needle insertion attempt while performing a subarachnoid block in comparison to the landmark-guided approach. The objectives of the following study were similar to that of the studies done by Chong et al [ 8 ], Creaney et al [ 9 ], Plewa et al [ 10 ], Perlas et al [ 11 ], Turkstra et al [ 12 ], Sahin et al [ 13 ], Lim et al [ 14 ], Kalagara et al [ 15 ].…”

Spinal Subdural Hematoma following Epidural Anesthesia

“…Finally, paraplegia following spinal or epidural anesthesia can be a subject matter for litigation and the person performing the procedure should be aware of the potential complications it entails and observe the patient in the postoperative period for immediate and delayed neurological deficits. Though not widely available, ultrasound-guided central neuraxial blocks have increasingly become the norm and must be utilized 17 if facilities are available to decrease chances of iatrogenic injury to intraspinal neural or vascular structures.…”

A comparative study of ultrasound assisted versus landmark technique for combined spinal-epidural anaesthesia in patients undergoing lower limb orthopaedic surgery

“…USG of the spine has a steep learning curve and necessitates a sound understanding of anatomy and how different parts of the vertebrae produce acoustic shadows. [ 19 ] A spinal ultrasound is particularly difficult because the neuraxial structures are not only deep but also protected by bones and because of its high acoustic impedance, bone obstructs the passage of ultrasound waves making identification of epidural/spinal space difficult. [ 20 ] Changes in patient position between preprocedural image acquisition and procedure can impact the accuracy of the neuraxial block.…”