Anatomy: Ultrasound guided interscalene block is performed at the root/trunk level of the brachial plexus (approx. C6/7 vertebral level, corresponding to the cricoid cartilage level). At this level, the roots/trunks lie wedged between the scalene muscles (Fig.1).ig. 1. Interscalane nerve block: illustration of the roots/trunks at the C6/7 vertebral level lying in between the anterior and middle scalene muscles. At the immediate supraclavicular level, the trunks/divisions are closely grouped superolateral (and posterolateral) to the subclavian artery.
When a word like and, or, and but (called conjunctions) joins two standalone sentences, you should put a comma before it. (The real name for a standalone sentence within a longer sentence is independent clause .). Words like and, or, and but are known as conjunctions.
This sentence has two independent clauses. They are connected by and with a comma before it. The and and the comma are correct. However, adding a comma after thus is not correct because it is an adverb; the comma after it is not necessary. If thus is used as a conjunctive adverb (without and), a semi-colon and a comma are necessary.