**4. Intraoperative analgesic techniques**

The axillary plexus is responsible for both internal and cutaneous innervation of the shoulder, except for the upper part of the shoulder, which is innervated by the supraclavicular nerve originated in the lower part of the superficial cervical plexus (C3–C4). The articular innervation and the structures that surround it are mainly in charge of the axillary nerve or circumflex and the suprascapular nerve. To a lesser extent, they can be innervated by the

The suprascapular nerve is a mixed, motor and sensory nerve, formed by the direct union of the upper primary trunk of C5 and C6, with occasional contributions of C4 in some variants. It occurs laterally below the trapezius and omohyoid, and enters the supraspinatus fossa. The transverse scapular ligament closes the fossa on the nerve. In the suprascapular fossa, the nerve sends motor branches to the supraspinatus and infraspinatus muscles and some to the teres minor. It provides sensitive branches to the posterior glenohumeral capsule, acromioclavicular joint, and the coracohumeral ligament. In 15% of patients, the suprascapular nerve receives cutaneous sensory fibers from the upper side of the arm (deltoid) [8].

musculocutaneous and subscapular nerve.

158 Advances in Shoulder Surgery

**Figure 1.** Division of the brachial plexus into its terminal branches.

Multiple advantages present loco-regional anesthesia:


The reference technique for intraoperative analgesia is brachial plexus block at interscalene level [9]. Multiple approaches have been described: Winnie, Pippa, and Meier are the best known. Until not many years ago, the use of the neurostimulator for the accomplishment of the blockade was the gold standard technique. It was recommended to obtain a good response of the triceps (C5–C6) rather than a response of the biceps (C4–C5), ensuring a better distribution of the anesthetic.

With the development of ultrasound techniques and their progressive introduction into anesthesiology services, the use of neurostimulation for nerve localization in analgesic or anesthetic blocks has become obsolete. At the moment, the realization of a blockade that is not guided by ultrasound is not conceived.

The use of this technology brings a number of advantages. One of the most important is to be able to confirm the distribution of the local anesthetic around the nerve by direct vision. The use of ultrasound also improves safety, since we observe at all times the trajectory of the needle and its relation with neighboring structures (vascular, pleura, and solid organs). Another notable advantage is that the volume of local anesthetic is considerably lower. The correct extension of the anesthetic around the nerve allows a shortening of the latency of the blockade and a longer duration of the effect.

Brachial plexus block at interscalene level has been well described and widely used (**Figure 2**). The lack of impact of suprascapular nerve block on respiratory function makes it a good

The use of catheters with continuous perfusion of local anesthetics accompanied by the possibility of self-administered boluses in shoulder surgery reduces the total dose of local anesthetic and the risk of side effects, and improves overall patient satisfaction. The use of an interscalene catheter is indicated mainly in patients who are going to undergo aggressive surgery with painful postoperative in the first 6 hours and in those patients who present the need for early and energetic rehabilitation. According to the type of surgery and patient char-

Integral Management in Painful Shoulder Treatment: Anesthesiologist's Point of View

http://dx.doi.org/10.5772/intechopen.69914

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The term "painful shoulder" encompasses all processes that determine pain in the anatomical region of the shoulder. "Painful shoulder syndrome" is a frequent and incapacitating pathology of diverse etiology and complex diagnosis. The causes of painful shoulder are multiple (**Table 2**). We should always ask if we are facing a disease of the shoulder or if it is a pain

acteristics, the catheter will be used between 3 and 5 days.

referred from another location.

Rupture of the rotator cuff tendon

Frozen shoulder (adhesive capsulitis)

Long biceps tendon rupture

 Inflammatory arthritis Microcrystalline arthritis Dislocation, subluxation

Vascular or somatic origin

Neurological origin

Fibromyalgia

Pancoast tumor, pneumothorax

Complex regional pain syndrome

**Table 2.** Etiology of painful shoulder.

 Aortic dissection, ischemic heart disease Atherosclerosis, vasculitis, aneurysms

Spinal cord injury, peripheral nerve entrapment

**Extrinsic causes**

**Periarticular**

**Articular**

Rotator cuff tendinitis

Bicipital tendinitis

**6. Analgesic techniques in treatment of chronic pain**

**Figure 2.** Ultrasound view of brachial plexus block at interscalene level. ASM, anterior scalene muscle; MSM, medium scalene muscle; BP, brachial plexus.

alternative in certain groups. To date, there have been no extensive trials comparing the efficacy and safety of the two, which could cause some reluctance to adopt suprascapular blockade as the regional technique of choice for shoulder surgery [10].

Good studies have recently appeared in this line. Dhir et al. [11] carried out a study with 60 patients in which they analyzed the combined blockade of the suprascapular and axillary nerves, comparing it with the interscalene brachial plexus block. They observed that the combined block provides nonequivalent analgesia compared to interscalene block in arthroscopic shoulder surgery. They conclude that while combined blockade provides better quality pain relief at rest and fewer adverse effects at 24 hours, interscalene block provides better postoperative analgesia. Therefore, for arthroscopic shoulder surgery, combined blockade may be a clinically acceptable analgesic option with a different analgesic profile compared to interscalene blockade.

However, Wiegel et al. [12] in a very recent study with 329 patients comparing the combined blockade of the suprascapular and axillary nerve with the interscalene blockade as analgesic techniques in arthroscopic shoulder surgery concluded that for outpatients subjected to arthroscopic surgery under general anesthesia, combined blockade seems preferable to interscalene. It provides excellent postoperative analgesia without exposing patients to alterations in mobility and the risks of interscalene blockade.
