Question

When performing an interscalene block with an with an in-plane posterior approach, the needle can be visualized going through which of the following structures?

A. Middle scalene muscle
B. Anterior scalene muscle
C. Adjacent to the phrenic nerve
D. Sternocleidomastoid muscle
E. Adjacent to the internal jugular vein

Answer 1

In an interscalene block with a posterior approach, the needle is visualized going through the middle scalene muscle, which is located between the anterior and posterior scalenes.

Step-by-step explanation:

When performing an interscalene block with an in-plane posterior approach, the needle can be visualized going through the middle scalene muscle. The middle scalene is the longest of the scalene muscles, situated between the anterior and posterior scalene muscles. The posterior approach aims to deposit local anesthetic near the brachial plexus, which is located between the anterior and middle scalene muscles. It is critical to visualize the needle accurately to avoid complications, such as injury to the adjacent phrenic nerve or internal jugular vein.