BLOCKMATE a practical guide for ultrasound guided regional.

This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd.

The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Regional anaesthesia has seen a resurgence of interest among anaesthesiologists in the recent past. The block techniques, obscure and unsure, hitherto have found validation in the clear imagery of ultrasound. Ultrasound-guided regional anaesthesia (USRA) over the last decade has become the standard of care and thereby a valuable skill in the repertoire of the anaesthesiologist. While the techniques are many and interesting, we found that there is a dearth of handy textbooks that the anaesthesiology resident or practitioner can carry in his pocket and use in the operating room for ready reference. The chapters in this book are brief, illustrative and problem oriented, ideal for the trainee or practitioner who is about to start his journey of regional anaesthesia practice. We have covered almost all the blocks in practice in anatomical order and given a brief introduction to the basics of ultrasound for ease of apprehension. The book also contains a chapter on safety and ergonomics of USRA, which is very important for the trainee, and a chapter on recent and upcoming advances in the field. While we will be bringing in new editions as the field of regional anaesthesia gets updated, we will appreciate the feedback from our readers. Please do write to us and let us know what you liked or disliked about our book and what more do you want from this book in the future editions.

I thankfully acknowledge the invaluable contribution of Dr. Ashokka Balakrishnan, MD, DNB, FANZCA, MHPE EDRA, without whose help this book would not have seen the light of the day. He has been a one-point solution for all the hurdles that I faced with the book. From connecting with contributing authors to getting his residents to draw the required diagrams, he has helped me overcome all the stumbling blocks of blockmate. I thank Dr. Shri Vidya for finding out time to help us with the diagrams. I thank our colleagues who helped us to collect the images and the volunteers and patients who gave their kind permission for using their images for this book. Lastly, I thank all my co-authors for their valuable contributions.

Sound waves are waves of compression and rarefaction in a medium such as air. For the propagation of sound, the most important factors are its frequency, wavelength and the qualities of the medium it travels through.

Only a part of the sound waves present in nature is audible to human ears, which is known as the hearing range. Human hearing range is between 20 and 20,000 Hz, although individual capabilities may vary. Any sound which has a frequency lower than 20 Hz is not audible to most humans and known as infrasound. On the other hand, the sound of frequency greater than 20,000 Hz is also inaudible to human ears and known as ultrasound. In the animal kingdom animals such as elephants can generate and hear the infrasound that allows them to communicate over a long distance, whereas bats and dolphins can generate and receive ultrasound which endows them survival edge in navigation and spatial orientation.