**6. Sedestatión beach chair position**

Described This was described in 1988 by Skyhar, whereby the patient sits on the operating table with the help of specially designed brackets, with the trunk flexed 60-80º to the horizontal. The hemithorax on the affected side must be free in the dorsal region to situate the posterior shoulder portal. The head and neck are supported by a specific device, with the head in slight flexion and extension, avoiding extreme rotation that could have a detrimental effect by overdistending the brachial plexus (Figure 2). This position also reduces the risk of brachial plexus injuries when compared with the lateral position, and it is better tolerated with only local anesthesia (Table 2).


Table 2. Characteristics of the Beach Chair Position

**Difficulty of penetrating the** 

**The conversion of arthroscopy** 

**Risk of excessive traction on** 

**Poorly tolerated with only** 

Described This was described in 1988 by Skyhar, whereby the patient sits on the operating table with the help of specially designed brackets, with the trunk flexed 60-80º to the horizontal. The hemithorax on the affected side must be free in the dorsal region to situate the posterior shoulder portal. The head and neck are supported by a specific device, with the head in slight flexion and extension, avoiding extreme rotation that could have a detrimental effect by overdistending the brachial plexus (Figure 2). This position also reduces the risk of brachial plexus injuries when compared with the lateral position, and it is

> **Poor display without pulling the joint and the axillary**

> **Difficulty moving the lens if the position is not maintained**

**joint due to the slope** 

**to open surgery is uncomfortable** 

**the brachial plexus** 

**local anesthesia** 

**Lateral benefits Disadvantages** 

**Better view of the joint space with traction** 

**More space for front and rear access** 

Table 1. Patient position

**6. Sedestatión beach chair position** 

better tolerated with only local anesthesia (Table 2).

**Better tolerated with local** 

**Reduced patient installation** 

**Reduce Reduced risk of** 

**conversion to open surgery** 

Table 2. Characteristics of the Beach Chair Position

**No need for traction** 

**Facilitates eventual** 

**neuroapraxia** 

**anesthesia** 

**time** 

**Advantages Disadvantages** 

**Upper limb mobility Increased associated risk of** 

**recess** 

**hypotension** 

**device** 

Fig. 2. Representation of the Beach chair position

The mMaintaining normothermia and preventing heat loss by the patient during surgery is essential due to the large amount of fluid infused into the joint. Hypothermia slows patient recovery. Indeed, shivering increases tissue oxygen demand and decreases cardiac output, thereby hindering proper oxygen and nutrient exchange to tissues, leading to acidosis. After surgery, the material that covers the patient is usually wet and cool, which also makes the patient cool. Using waterproof materials is effective, as is good continued aspiration of the instilled fluid. Furthermore, mechanical ventilation lowers the temperature by using a cold gas. Fluid heating systems and convection heating elements are usually effective in this kind of surgery for prophylaxis of hypothermia.

The interscalene and supraclavicular approaches to the brachial plexus (above the clavicle or proximal), have proven effective and safe for anesthesia and post-operative analgesia in arthroscopic shoulder surgery. Recently, a new safe and effective approach to arthroscopic shoulder surgery was advocated, blocking the suprascapular nerve and axillary nerve, although this is a preliminary study (15). The parascalene approach is also thought to offer safe and effective anesthesia for these procedures, as well as a unique benefits in the treatment of acute postoperative pain (16).

The intercostobrachial nerve comes from the thoracic nerve roots T1-T2 and it is responsible for the sensitivity of the anteromedial aspect of the arm. Since some techniques do not block the supraclavicular nerve, this is achieved with a subcutaneous wheel and 3-5 ml of local axillary anesthetic, superficial to the area of palpation of the axillary artery (Figure 3).

Anesthesia for Arthroscopic Shoulder Surgery 57

Fig. 4. A. Representation of the most relevant references in the neck skin to the perform an

In the resulting image and for educational purposes, three areas can be identified when using this approach. A superficial area (located in the upper area of the ultrasound screen) occupied mainly by muscle structures, most of them more shallow than the sternocleidomastoid muscle. A middle zone located immediately under the muscle plane described above in which the tracheal lumen and cricoid cartilage lie, and lateral to the tracheal lumen the homogeneous texture of the thyroid lobe can be observed (Figure 5a), together with two vascular structures: a) the most inner and rounded one going up to the pulsating carotid artery; and b) the outer triangular one that readily collapses on applying pressure with the scanning probe corresponds to the internal jugular vein (Figure 5b). A deep zone (located in the lower area of the ultrasound screen) the lower limit of which marks the vertebral transverse process, which at this level corresponds to C6. Once these structures have been identified, the probe can be moved laterally and by maintaining the

Neurolocalization by ultrasound. D. Plexus approach using ultrasound with needle

interscalene block. B. Material for blockade by neurostimulation. C. Plexus

same angle, interscalene scan plane is reached (Figure 5c).

insertion "flat" from the side.

Fig. 3. Schematic representation of the sensitive area of the intercostobrachialis nerve.
