Where is anesthetic injected during a scalene block?

The scalene block involves the injection of anesthetic at the location of the scalene muscles, specifically targeting the brachial plexus as it lies in proximity to these muscles. The scalene muscles, located in the lateral aspect of the neck, serve as a critical anatomical landmark for this procedure. By injecting anesthetic into this area, the anesthetic effectively surrounds the roots of the brachial plexus, providing regional anesthesia to the upper extremity.

This approach is particularly beneficial for procedures on the shoulder and arm, as it can obstruct nerve signals originating from the brachial plexus, resulting in effective pain relief during surgical interventions. Knowledge of the anatomy surrounding the scalene muscles, particularly the arrangement and branches of the brachial plexus, is vital for successfully performing this block and minimizing potential complications.

In contrast, other options do not accurately represent the correct anatomical target for a scalene block. Injecting into the neck muscles, for instance, would not effectively address the nerve root components necessary for anesthesia in the arm and shoulder. Similarly, injecting anesthetic into the carotid artery or the chest wall would not achieve the desired effect of blocking sensation in the upper extremity, as these locations do not contain the brachial plex