An Introductory Curriculum for Ultrasound-Guided Regional Anesthesia: A Learner's Guide.

Abstract

Northwestern University Feinberg School of Medicine, Chicago, Illinois.bachung@northwestern.eduAn Introductory Curriculum for Ultrasound-Guided Regional Anesthesia: A Learner's Guide. Edited by Brian A. Pollard, B.Sc., M.D., Med., F.R.C.P.C., and Vincent W. S. Chan, M.D., F.R.C.P.C. Toronto, University of Toronto Press UTPRINT, 2009. Pages: 81. Price: $109.00.The burgeoning use of ultrasound imaging to guide the performance of regional anesthesia has breathed new life into an already dynamic and compelling field. The anesthesia residents at my institution have minimal interest in using anatomic landmarks and nerve stimulation alone for guidance in peripheral nerve blocks. It is now all about the ultrasound. As a result, there is a considerable demand for quality resources on ultrasound-guided regional anesthesia for primary learning as well as for reference. This text is well-designed to help meet this need on an introductory level. Its target audience will likely extend from trainees at the beginning of their anesthesia careers to well-seasoned practitioners of regional anesthesia who are only recently incorporating ultrasound imaging as guidance for their peripheral nerve blocks.The text is divided into five sections. The first lays the foundation required for the practice of ultrasound-guided regional anesthesia, a basic science understanding of ultrasound. Because the physics of ultrasound can be tedious and not particularly useful in clinical practice, the authors do not delve deeply into how an electric current will cause a physical transition of a piezoelectrical crystal, for example. Rather, they describe why higher transducer frequencies provide excellent image resolution within superficial tissues and why this is not the case at greater tissue depths. Emphasis on this type of knowledge has direct clinical applications to the attainment of high quality images, and, by extension, successful blocks.Real-time ultrasound imaging elevates a blurry canvas of whites, blacks, and grays to form a cinematic movie showing anatomic structures, and, like holding a camera, one controls the image by guiding the transducer. The authors discuss practical techniques for manipulating the transducer, such as sliding and tilting, to improve the attainment, interpretation, and overall quality of the images. Their favored practice target is one's own forearms, which have a wealth of structures to examine.Included in the first section is a discussion on the use of needles in conjunction with an ultrasound transducer. Using the two in combination is a skill to be gained in its own right. The emphasis on this is critical for the successful and safe execution of regional anesthesia with ultrasound guidance. One useful pearl is for the practitioner to avoid “chasing” the needle while using the in-plane technique but to strive always to guide the needle to the target in the existing optimal image.Only after this introduction are we ready to explore the blocks themselves. The next three sections describe ultrasound-guided nerve blocks in order of increasing complexity. Forearm blocks are discussed along with single-shot femoral nerve blocks as part of the introductory or beginner blocks. The intermediate blocks include the different approaches to target the brachial plexus and sciatic nerve. The final section on peripheral blocks includes a discussion on indwelling peripheral nerve catheters. The fifth, and final, section of the text focuses on ultrasound-assisted neuraxial blocks. The authors make the distinction between “assisted” and “guided,” as these techniques are used mainly to help establish landmarks and depth. True ultrasound guidance depends on real-time images.The recommendations at the end of each chapter are helpful for those wanting or needing further depth in the subject material. The bullet points at the conclusion of each chapter provide a distillation of the most important concepts. The images and illustrations are of high quality and occupy nearly as much real estate as the written text, which is fitting for a book on image guidance. The cross-sectional magnetic resonance images are particularly helpful for those trying to grapple with 2D images in planes they may not be used to visualizing. The book repeatedly highlights the continued need for a solid understanding of anatomy, whether or not ultrasound is employed.In terms of critique, I will return again to a subject that was a rite of passage for all physicians: physics. Although the discussion that relates to ultrasound energy was made brief by intent, it was still not exceptionally clear. However, this is probably because the subject of ultrasound physics itself is not particularly suited to brevity and thus becomes a bit of an impossible task for an introductory guide. Overall, An Introductory Curriculum for Ultrasound-Guided Regional Anesthesia: A Learner's Guide is an easy-to-read, informative text. With an efficiency of words, it remains meaty enough to start feeding the scholarly appetite for ultrasound-guided regional anesthesia and will likely spur further study as well as hands-on practice.Northwestern University Feinberg School of Medicine, Chicago, Illinois.bachung@northwestern.edu