4 Supraclavicular and Infraclavicular Techniques of Brachial Plexus Block



10.1055/b-0035-124646

4 Supraclavicular and Infraclavicular Techniques of Brachial Plexus Block



4.1 Anatomy


Just above the clavicle, each of the trunks splits into an anterior and a posterior division:




  • The three posterior divisions combine to form the posterior cord.



  • The anterior divisions of the upper and middle trunks form the lateral cord.



  • The medial cord is the continuation of the anterior division of the lower trunk (Fig. 4.1 and Fig. 4.4).

Fig. 4.1 Brachial plexus, infraclavicular region. 1 Cephalic vein 2 Subclavian artery 3 Medial cord 4 Lateral cord 5 Posterior cord 6 Subclavian muscle

The cords are located very close to one another in the infraclavicular region (Fig. 4.2, Fig. 4.3, Fig. 4.4, Fig. 4.5, Fig. 4.6, Fig. 4.7, Fig. 4.8).

Fig. 4.2 Anatomy of the infraclavicular region, seen from cranial aspect. 1 Scalenus anterior 2 Subclavian artery 3 Medial cord 4 Lateral cord 5 Posterior cord 6 Suprascapular nerve 7 Scalenus medius 8 Pleural cavity
Fig. 4.3 Brachial plexus, infraclavicular region. 1 Subclavian vein 2 Subclavian artery 3 Pectoral nerves 4 Brachial plexus 5 Cephalic vein
Fig. 4.4 Anatomy of the brachial plexus. 1 Subclavian artery 2 Medial cord 3 Posterior cord 4 Lateral cord 5 Upper trunk 6 Middle trunk 7 Lower trunk 8 Sternocleidomastoid
Fig. 4.5 Brachial plexus in relation to the subclavian (axillary) artery. Note that the cords rotate 90° around the subclavian artery from the infraclavicular region to the axillary region. While the posterior cord is furthest laterally (but deeper) compared to the lateral cord in the infraclavicular region, in the axillary region the names of the cords correspond to their actual positions relative to one another. 1 Lateral cord 2 Posterior cord 3 Medial cord
Fig. 4.6 Lateral aspect of the interscalene groove with the shoulder raised. 1 Upper trunk 2 Scalenus anterior with phrenic nerve 3 Subclavian vein 4 First rib 5 Subclavian artery 6 Lower trunk
Fig. 4.7 Anatomy of the brachial plexus. 1 Radial nerve 2 Median nerve 3 Musculocutaneous nerve 4 Posterior cord 5 Lateral cord 6 Suprascapular nerve 7 Ulnar nerve 8 Medial cutaneous nerve of the forearm 9 Medial cord
Fig. 4.8 Anatomy of the infraclavicular region. 1 Cephalic vein 2 Subclavian artery 3 Lateral cord 4 Medial cord 5 Posterior cord



  • The lateral cord lies most superficially (lateral to and in front of the subclavian artery).



  • The posterior cord is found a little deeper and slightly lateral to the lateral (!) cord (lateral to and behind the subclavian artery).



  • The medial cord lies deep (behind the subclavian artery, see Fig. 4.3 and Fig. 4.4).


The subclavian artery and the brachial plexus run medial to the coracoid process to the axilla.



Note


Note the 90° rotation of the cords around the subclavian artery from the infraclavicular to the axillary region. While the posterior cord lies furthest lateral (but deeper) compared with the lateral cord in the infraclavicular region, the designations of the cords reflect their actual positions in the axillary region.


The medial cord passes below the artery and then lies medial to the artery, giving off a medial root that joins the lateral root of the lateral cord to form the median nerve.



4.2 Supraclavicular Block Techniques


The supraclavicular block of the brachial plexus, similarly to the infraclavicular block, has the advantage that the nerves supplying the arm are bundled very compactly in the area where the trunks separate into the cords. However, the classical supraclavicular block techniques by Kulenkampff (Kulenkampff 1911) and later Winnie and Collins (1964) have been used less than the infraclavicular block in recent decades due to the increased risk of pneumothorax. The introduction of ultrasound-guided techniques has, at least theoretically, the advantage of minimizing the risk of pneumothorax, although a pneumothorax cannot be completely precluded even with ultrasound (Bhatia et al 2010).


Sensory and motor effects, indications and contraindications, and complications, side effects, and method-specific problems are, unless specified otherwise, similar to those of the infraclavicular block techniques (Chapter 3.2.3).



Note


The supraclavicular plexus block should be performed only under ultrasound guidance and possibly with a nerve stimulator as well.



4.2.1 Ultrasound-Guided Supraclavicular Block of the Brachial Plexus


Linear transducer: 10 to 12 MHz


Needle: 6 to 10 cm



Visualization of the Brachial Plexus Using Ultrasound

As already described for the trace-back method for locating the interscalene brachial plexus (Chapter 3.2.3), the transducer is placed immediately above and parallel to the clavicle in the supraclavicular fossa and the beam is directed obliquely under the clavicle toward the thorax (not perpendicularly; Fig. 4.9).

Fig. 4.9 Visualization of the right supraclavicular plexus using ultrasound (“sonoanatomy”). Note the angle between the subclavian artery and the first rib (corner pocket). Here are segments of the brachial plexus (marked with an *), from which the medial cord and the ulnar nerve are formed. a Clinical setting. b Ultrasound image (unlabeled). c Anatomy (section in the acoustic window). d Ultrasound image (labeled). e Anatomy (section in the acoustic window with markings). 1 First rib 2 Subclavian artery 3 Brachial plexus 4 Pleura

First the subclavian artery (round, pulsating, hypoechoic structure) is visualized. If the finding is unclear, color Doppler can be used to clarify the situation. Lateral and slightly anterior to the subclavian artery is the brachial plexus, visible as a bundle of small, hypoechoic circles (grapelike structure; Fig. 4.9)



Needle Approach

The in-plane needle approach from lateral to medial is preferred to avoid a pneumothorax (Fig. 4.10). The needle is inserted at the lateral end of the transducer and advanced in the beam strictly along the transducer axis up to the desired structures. As in the interscalene block, a slight loss of resistance is felt when the fascia surrounding the plexus (prevertebral fascia) is penetrated. This phenomenon is also visible in the ultrasound image as a slight depression of the fascia followed by recoil (loss of resistance).

Fig. 4.10 Supraclavicular plexus block, ultrasound-guided in-plane puncture. Arrow (dash-dot line): needle direction. Arrow (dotted line): correction possibly needed if local anesthetic does not reach corner pocket (as in d, e). a Patient position. b Before injection of the local anesthetic. c With structures marked. d After injection of the local anesthetic. e With structures marked. 1 Pleura 2 First rib 3 Brachial plexus 4 Subclavian artery 5 Scalenus anterior 6 Scalenus medius 7 Omohyoid 8 Brachial plexus (after injection of the local anesthetic)

A few milliliters are injected to check whether the local anesthetic spreads in the correct compartment. It is crucial that the local anesthetic also spreads into the deep nerve structures in the angle between the first rib and the subclavian artery (corner pocket; Fig. 4.9), as there may otherwise be an incomplete block in the region of the ulnar nerve (Fig. 4.10). Information on the required volume of local anesthetic to be applied fluctuates between 15 mL (Soares et al 2007) and 30 mL (Fredrickson et al 2009, Perlas et al 2009).



Catheter Placement

A catheter can be placed using the technique described here, but is less successful than infraclavicular catheter placement with respect to postoperative analgesia (Mariano et al 2011). The reason for this is the unfavorable angle between the needle and the course of the brachial plexus for advancing the catheter.



Tips and Tricks




  • The ultrasound-guided supraclavicular block can be performed in combination with nerve stimulation. As described above, a response in the hand should be striven for. Note: After administration of local anesthetic and/or normal saline, the function of the nerve stimulator is impaired! Use dextrose 5% if necessary.



  • The targeted application of the local anesthetic in the corner pocket between the first rib and the subclavian artery should lead to a very reliable block with rapid onset (Soares et al 2007, Tran et al 2006). However, a comparative study of this method with the “in plane” infraclavicular plexus anesthesia showed a better block in the region of the ulnar nerve with the same onset time (30 min; Fredrickson et al 2009) in favor of the infraclavicular block.



  • In the same visualization of the supraclavicular brachial plexus as described above (in the short axis), an out-of-plane puncture similar to the perivascular supraclavicular block described by Winnie and Collins (Tran et al 2008) is also possible. The angle to the transducer should be as steep as possible. Using continuous small movements (local tissue movement, see Chapter 1), the practitioner can determine the position of the tip of the needle. The risk of a pneumothorax may be greater than in the in-plane technique. A catheter is easier to place.



4.3 Vertical Infraclavicular Block According to Kilka, Geiger, and Mehrkens


In contrast to the other infraclavicular techniques, the vertical infraclavicular block (VIB) described by Kilka et al (1995) has clear landmarks.


These landmarks are the anterior end of the acromion and the middle of the jugular notch. The midpoint of the line connecting these two points marks the injection site, which here lies just below the clavicle (Fig. 4.11 and Fig. 4.12).

Fig. 4.11 Orientation points for vertical infraclavicular plexus anesthesia. (The puncture site is half way between the middle of the jugular notch and the anterior part of the acromion.) 1 Middle of the jugular notch 2 Puncture site 3 Coracoid process 4 Head of humerus 5 Anterior part of the acromion
Fig. 4.12 Overview of the bony structures for performing vertical infraclavicular plexus anesthesia. 1 Head of humerus 2 Coracoid process 3 Anterior part of the acromion


4.3.1 Positioning


The patient lies supine; special positioning of the arm is not necessary. If possible, the patient′s hand should lie comfortably on his or her abdomen (Fig. 4.13).

Fig. 4.13 VIB puncture site: vertical to surface on the horizontal supine patient. Note the relation to the supraclavicular region.


4.3.2 Needle Approach


The needle approach is performed just below the clavicle strictly vertical (perpendicular) to the surface the patient is lying on (Fig. 4.14 and Fig. 4.15).

Fig. 4.14 VIB puncture site: vertical to surface on the horizontal supine patient. Note the relation to the supraclavicular region.
Fig. 4.15 Anatomy of the infraclavicular region, view from above. 1 Cephalic vein 2 Subclavian artery 3 Lateral cord 4 Posterior cord 5 Sternocleidomastoid 6 Upper trunk 7 Omohyoid with medial cervical fascia

After penetrating clavipectoral fascia, which is often very tough, there is a stimulus response after 2.5 to 4 cm. Peripheral muscle contractions in the fingers are striven for as a response indicating success (posterior cord/radial nerve, lateral cord/median nerve, medial cord/ulnar nerve). Stimulation of the lateral cord only, which leads to contraction of the biceps muscle and/or pronator teres, may result in an incomplete block. In order to obtain a successful response, the needle in this case must be withdrawn to a subcutaneous position, and after moving the skin slightly more laterally (0.5 to 1.0 cm) it should be advanced again vertically to the underlying surface. The desired response is about 0.5 cm deeper and is then usually in the region of the posterior cord, which here lies laterally (care !) and deeper than the lateral cord.


Needle.


A 4 to 6 cm long insulated needle is used; a catheter technique is possible. The needle is inserted just below the clavicle strictly vertical (perpendicular) to the surface the patient is lying on.



Tips and Tricks




  • Because of the potential danger of a pneumothorax, a medial needle direction, a puncture site too far medially, and excessively deep puncture should be avoided at all costs (Fig. 4.16). The depth of puncture must never be more than 6 cm even in large patients. In slim patients where the distance between the acromion and the jugular notch is short (< 20 cm), the risk of a pneumothorax is increased, as the plexus is sometimes located at a depth of < 3 cm (Neuburger et al 2001). Even when all the rules are followed, a pneumothorax cannot always be avoided (Neuburger et al 2000).



  • When the distance from the acromion to the jugular notch is < 20 cm it is advisable to move the puncture site further laterally by 0.3 cm for each centimeter by which the distance falls below 20 cm (e.g., jugular-acromion distance 17 cm; puncture site not 8.5 cm but 7.6 cm from the anterior end of the acromion or 9.4 cm from the middle of the jugular notch on the J–A line; Neuburger et al 2003).



  • The injection point is largely identical with the medial boundary of the “infraclavicular fossa” (clavipectoral trigone or Mohrenheim fossa). The plexus emerges under the clavicle exactly at the lateral margin of the superficial part of pectoralis major. The so-called “finger point” (Fig. 4.17) acts as an additional orientation and thus provides certainty that the correct injection site has been defined. The anesthetist′s index finger (right index finger when the right limb is to be blocked, left index finger when the left limb is to be blocked) is placed in the gap between the deltoid and pectoralis major muscles and pressed laterally on the coracoid process. The tip of this finger encounters the clavicle and its ulnar border marks the medial margin of the infraclavicular fossa (deltopectoral groove) and thus the puncture site (Neuburger et al 2003).

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Jun 8, 2020 | Posted by in ANESTHESIA | Comments Off on 4 Supraclavicular and Infraclavicular Techniques of Brachial Plexus Block
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