Following an interscalene block, where would pain typically be reported if there is inadequate local anesthetic spread?

In the context of an interscalene block, the primary target is usually the brachial plexus, which innervates the shoulder, arm, and parts of the hand. If the local anesthetic does not adequately spread, the areas that typically receive pain sensation can provide key insights into where the block is ineffective.

Choosing to report pain along the ulnar aspect of the distal forearm indicates that the local anesthetic did not sufficiently affect the nerves responsible for sensations in that area, specifically those innervating the ulnar side of the forearm and hand. The ulnar nerve primarily supplies the ulnar side of the forearm and hand, and if the block does not adequately cover this area, pain sensation may persist there.

Interscalene blocks have a more significant impact on the shoulder and upper arm regions but are less effective in providing analgesia to the distal forearm. This aligns with the understanding that inadequate spread may lead to retention of pain sensations in regions beyond the primary target of the block, illustrating how the area affected can help assess the adequacy of anesthetic coverage. This context supports the idea that reporting pain along the ulnar aspect signals inadequate coverage in the relevant nerves, making it the