**14. Performing the technique**

To achieve the supraclavicular block, the patient is placed in a prone position with the head turned slightly to the side contralateral to the blockade and with their arm parallel against their body. The probe is placed just above the collarbone, parallel to it, and the map obtained is the oblique coronal plane, that offers a cross section of the subclavian artery. In At this site, the brachial plexus is located approximately 1 cm from the skin and therefore, it is advisable to use high-frequency (10-15 MHz) and low penetration (3-4 cm) probes for exploration (Figure 6).

The needle is inserted through the lateral end of the probe, moving at an angle of about 20° to the skin and parallel to the transducer. After inserting the needle tip into the plexus and gentle aspiring, the local anesthetic solution is slowly injected. A sign of good distribution of the local anesthesia is the peripheral displacement of the divisions/trunks that form the plexus at this level, and the strengthening of their hyperechoic rim. It is recommended that the needle be replaced if the local anesthetic is distributed asymmetrically.

 May require superficial Superficial cervical plexus block may be required (sensitive innervations of the skin over the shoulder on top and above). This can be achieved by infiltrating 5-10 ml of anesthetic in a fan at the posterior lateral edge of the sternocleidomastoid muscle from the midpoint of an imaginary line between the

The supraclavicular fossa is limited by the outer edge of the sternocleidomastoid muscle, the middle third clavicular and the anterior border of trapezius. When the trunks of the brachial plexus abandon the interscalene space, they form 6 divisions, 3 above and 3 below. The brachial plexus is directed from the corresponding interscalene space to the axilla, passing over the 1st rib between the attachments of the anterior and middle scalene muscles, and below the collarbone. When the plexus lies between the first rib and the clavicle, it remains surrounded by a fascial sheath, maintaining a close relationship to the subclavian artery, although extending above and remaining external to it. The subclavian vein is located above

For ultrasound imaging of the brachial plexus, the supraclavicular ultrasound probe should be placed in the supraclavicular fossa, parallel to the clavicle and the edge, touching its inside while at an angle to the chest. This represents the "guide" to locate the subclavian artery. It is desirable that this approach is made at a level that includes the artery in the center of the image, clearly positioned on the first rib, leaving the farthest edge of the pleura on each side. In that way, the nerves will be situated in a superior position external to the artery. It is sometimes possible to observe a cross-section of the subclavian vein, which appears as a hypoechoic round structure that does not pulsate, with internal strings of images that correspond to valvular structures. Anatomically, it is situated before the insertion of anterior scalenus muscle, and thus medial to the muscle in the image, and in

To achieve the supraclavicular block, the patient is placed in a prone position with the head turned slightly to the side contralateral to the blockade and with their arm parallel against their body. The probe is placed just above the collarbone, parallel to it, and the map obtained is the oblique coronal plane, that offers a cross section of the subclavian artery. In At this site, the brachial plexus is located approximately 1 cm from the skin and therefore, it is advisable to use high-frequency (10-15 MHz) and low penetration (3-4 cm) probes for

The needle is inserted through the lateral end of the probe, moving at an angle of about 20° to the skin and parallel to the transducer. After inserting the needle tip into the plexus and gentle aspiring, the local anesthetic solution is slowly injected. A sign of good distribution of the local anesthesia is the peripheral displacement of the divisions/trunks that form the plexus at this level, and the strengthening of their hyperechoic rim. It is recommended that

the needle be replaced if the local anesthetic is distributed asymmetrically.

 Do not hold bilateral blocks in patients with respiratory disease. It is not entirely clear whether alterations can be made in hemostasis.

**13. Supraclavicular approach of brachial plexus** 

the 1st rib and enters into the anterior scalene muscle.

most cases it is obscured by the clavicle.

**14. Performing the technique** 

exploration (Figure 6).

Other considerations and peculiarities:

mastoid and the clavicle.

an even distribution of the local anesthetic will produce blockade in all the territories dependent on the brachial plexus nerve in > 80% of cases. To achieve uniform distribution of the anesthetic, a slow injection is paramount, along with high resolution ultrasound to directly observe its distribution.

Fig. 6. A. Ultrasound anatomy of the supraclavicular brachial plexus. B. Schematic representation of the scalene muscles (orange), subclavian artery (red), first rib (white) and brachial plexus (Yellow)

The Brachial plexus blockage via the supraclavicular approach has some notable advantages:

