Regional Anesthesia for Shoulder and Clavicle Surgery

*Ciro Alfonso Rodríguez-Gómez, José Ramón Saucillo-Osuna and Karen L. Iñiguez-López*

## **Abstract**

The shoulder joint and clavicle are innervated by the brachial plexus, the cervical plexus, and nerves to muscles around the joint and clavicle. Regional anesthesia is aimed at producing optimal surgical conditions, prolonging postoperative analgesia, being free of complications, reducing costs, and minimizing hospital stay. Regional upper extremity anesthesia can be achieved by blocking the brachial plexus at different stages along the course of the trunks, divisions, cords, and terminal branches. The gold standard of regional anesthesia for shoulder surgery is interscalene brachial plexus block plus cervical plexus block, but it is associated with a high rate of neurological complications and phrenic nerve block. The interest of the anesthesiologist has been directed towards regional blocks avoiding these complications; techniques that approach nerves more distally than interscalene block have been described. These approaches include supraclavicular nerves, upper trunk, suprascapular nerve by anterior approach, axillary nerve block in the axillary fossa, clavipectoral fascia block. The objective of this chapter is to describe the anatomy, sonoanatomy, technique, and the clinical utility of these accesses.

**Keywords:** regional anesthesia, shoulder, clavicle, upper trunk, supraclavicular nerves, suprascapular nerve, axillary nerve, clavipectoral fascial, interscalene block

#### **1. Introduction**

Shoulder surgery by arthroscopy or open methods has increased in recent years. The choice of anesthetic technique depends on the patient's conditions, the preferences of the surgical group, the position the patient is to be placed, and the experience of the anesthesiologist. General anesthesia (GA) has been considered the ideal technique for this type of surgery, but advances in regional anesthesia have gradually changed this statement. The approaches, interscalene (ISBP) block (C5 C6) or the upper trunk (UT) are the most established options; the supraclavicular approach offers optimal coverage, including the proximal arm. Patients with respiratory compromise may not tolerate hemi diaphragmatic paresis (HDP) associated with proximal approaches. Distal approaches are associated with lower rates of HDP, but coverage of the proximal upper extremity may be incomplete. The use of ultrasound guidance (USG) for nerve blocks has increased success and safety and has allowed access to more peripheral brachial plexus blocks to prevent diaphragmatic paralysis. Regional anesthesia is also an excellent supplement to GA to improve postoperative pain management and decrease the need for opioid use.

Clavicle surgery has even more controversy about the choice of the regional block, since the innervation has not been well described. But in recent years, alternative regional block methods to interscalene brachial plexus block have appeared that are suitable as single anesthesia or combined with sedation or GA.

In this chapter, we pretend to describe the innervation of the shoulder and clavicle based on current knowledge and the sonoanatomy of the neck and armpit as a guide for the performance of regional nerve blocks.
