The Loss of Resistance Nerve Blocks

Presently ultrasound guided nerve blocks are very fashionable but vast majority of people around the world cannot practice these techniques mostly due to lack of resources but even in the developed countries there is lack of training which precludes people from using it. Lack of resources does not mean that patient cannot be provided with appropriate pain relief using nerve blocks. There are some nerve blocks that can be done using the loss of resistance (LOR) techniques. These blocks like, tranversus abdominis plane (TAP), rectus sheath, ilio-inguinal and fascia iliaca blocks can be effectively utilized to provide pain relief in the peri-operative period. For these blocks to be effectively delivered it is essential to understand the anatomical basis. It is also important to understand the reasons for failure, which is mostly due to delivery of the local anaesthetic in the wrong plane. The technique for LOR is not only simple and effective but also it can be delivered with minimal resources. This article deals with the techniques used for LOR blocks, the relevant anatomy and the methods used to administer the blocks. The article also describes the various indications where these blocks can be utilized, especially in the post-operative period where the pain management is sub-optimal.