Functional anatomy of the nerve and optimal placement of the needle for successful (and) safe nerve blocks

Purpose of review Summarize the current thinking concerning the clinically relevant aspects of nerve anatomy and best injection sites for nerve blocks. Recent findings The widespread use of ultrasound in regional anesthesia has changed the practice of regional anesthesia and created new possibilities. Among them is the ability to identify fascial planes, and this has become the basis for a new group of blocks, the fascial plane blocks. In this kind of blocks, the target for injection is the plane itself and not a nerve in particular. transversus abdominis plane, pectoralis muscles, erector spinae plane blocks are some examples of fascial blocks. Because injecting into a fascial plane is not controversial, these blocks are not included in our discussion of optimal placement of the needle. To determine optimal needle placement, it is important to have a clear definition of what constitutes intraneural. Although, there is almost universal agreement that the violation of the epineurium defines the intraneural concept, the literature include several studies where this assessment is erroneous. Although intentional intraneural injection is still considered objectionable, some literature suggests that injecting intraneurally, especially if extrafascicular, may be benign. This evidence is limited and anecdotal. Summary It is necessary to have a better understanding of what intraneural injection is when dealing with any type of nerve blocks, be that single nerve, plexuses, or...
Source: Current Opinion in Anaesthesiology - Category: Anesthesiology Tags: REGIONAL ANESTHESIA: Edited by Nabil Elkassabany Source Type: research