- Email: [email protected]
Supraclavicular blocks of the brachial plexus
Techniques in Regional Anesthesia and Pain Management (2006) 10, 95-105
Supraclavicular blocks of the brachial plexus Carlos A. Bollini, MD, Fernando Cacheiro, MD, Carlos Salgueiro, MD, Miguel Moreno, MD From the Servicio de Anestesia del Instituto Argentino de Diagnostico y Tratamiento, Capital Federal, Argentina; the Servicio de Anestesia del Hospital Municipal “Juan A. Fernandez,” Capital Federal, Argentina; and the Servicio de Anestesia del Hospital Universitario Austral, Pilar, Buenos Aires, Argentina. KEYWORDS: Supraclavicular; Brachial plexus; Regional anesthesia
The concept of a continuous perineural and perivascular space surrounding the brachial plexus from roots to terminal nerves, allows the injection of a local anesthetic at any level from the neck to the axilla. A complete anesthesia of the entire upper extremity can be simple, safe and effectively provided by blocking the brachial plexus using any supraclavicular approach. At the supraclavicular fossa the plexus is most compactly arranged and local anesthesia is delivered at the trunks level. The different approaches described, can be performed with the upper extremity in any position especially in those patients not suitable for an axillary block. All the supraclavicular approaches offer a high success rate and avoid the sparing of the ulnar nerve with the interscalene technique and the musculocutaneous often missed with the axillary block. All these approaches carry a greater risk of pneumothorax. With the use of the peripheral nerve stimulator, the old Kulenkampff technique is now in a period of renaissance. © 2006 Elsevier Inc. All rights reserved.
These blockades include all those approaches of the brachial plexus that are performed immediately above the clavicle. They can be classified into supraclavicular techniques strictly so-called, low interscalene and parascalene. Supraclavicular blockades provide, with a single injection, complete anesthesia of the upper extremity. Most of these techniques were originally described with the purpose of reducing pneumothorax incidence. Pneumothorax is a feared complication typically associated with classic supraclavicular blockade by Kulenkampff.1 By any of these routes, one can achieve appropriate surgical blockade of the upper extremity. However, supraclavicular injection of the local anesthetic produces a quicker and more homogeneous blockade. The point of injection anatomically coincides with the site where all the trunks are grouped among themselves (sandglass narrowing). This site includes nerves, such as the circumflex and musculocutaneous ones, that have not left the sheath yet. This is the reason why such nerves will be difficult to block with lower routes. Therefore, supraclavicular approaches have been proposed as the
Address reprint requests and correspondence: Carlos A. Bollini, MD, J.D. Peron 2375, 1629 Pilar, Buenos Aires, Argentina. E-mail address: [email protected]. 1084-208X/$ -see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1053/j.trap.2006.07.010
most effective and uniform procedures for the entire brachial plexus.2,3
History Multiple approaches of the brachial plexus above the clavicle have been described. The first and best known is the classic supraclavicular by Kulenkampff.1 Although it seemed to have fallen into disuse, recent publications support its popularity4,5 due to the use of the neurostimulator. After this approach, many others appeared. Among them are: the subclavian perivascular by Winnie,6 the parascalene by Vongvises and Panijayanond,7 the one by Dupré and Danel,8 the “plumb-bob” approach by Brown,9 the supraclavicular lateral paravascular by Moorthy,10 the posterior approach by Pippa,11 the supraclavicular perivascular modified by Ortells-Polo,12 and the intersternocleidomastoid by PhamDang,13 among many others.14 The great diversity of techniques with minimum variants supports the idea that none of them is the perfect technique or is exempt from potential risks. In fact, cases of major complications have been published with almost every technique. They include: pneumothorax, radicular lesion, medullary lesion, vascular puncture (vertebral, subclavian, jugular), subarachnoid or epidural
96
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006
injection, acute breathing insufficiency, cardiovascular collapse, bilateral blockade, bronchospasm, unconsciousness, apnea, etc. However, the techniques of supraclavicular approach are, beyond any doubt, the most effective techniques. They will provide the best quality, consistency, and shortest waiting time of brachial plexus blockade for the entire upper extremity. With these procedures, the local anesthetic acts at the level of the trunks and divisions of the brachial plexus. These boarding routes allow blockade of the higher number of nerves that originate in this plexus, provided paresthesia or neurolocalization were effective. In case of using them for shoulder surgery, the cervical plexus that innervates the skin of the shoulder should be blocked separately, even in the case of slight cephalic diffusion of LA. Although they are easy to execute, these techniques are difficult to teach and learn; maybe because all variants are circumscribed to a triangular surface of 5 cm and its anatomy and precise anatomical references can be easily confused in the absence of adequate practice.
Indications ●
● ● ● ●
●
Surgeries below the shoulder (arm, forearm, and hand). These techniques are very useful when access to the axilla is impossible regardless of the cause (tumor, infection, etc.). Shoulder surgery with appropriate complementation. Surgery of the elbow: fractures, arthroscopy, resection of the head of the radius. Transposition of the cubital nerve. The musculocutaneous and cubital nerves are blocked. However, in the axilla accessory to the internal brachial cutaneous, internal brachial cutaneous and intercostobrachial nerves must be supplemented. Preventive analgesia, treatment of postoperative pain in shoulder surgery, reduction of shoulder luxations, sympathetic blockade for reflex, sympathetic Dystrophy, causalgia, vascular surgery, Raynaud syndrome.
Preparation of patients before blockade Before any regional blockade, one should always settle a standard ASA monitor (EKG, blood pressure and saturation of O2), and an IV line in the contralateral upper extremity. Reanimation kit should be ready. For most supraclavicular techniques, we prefer light sedation with midazolam (from 0.01 to 0.02 mg/kg).
Brachial plexus blockade at supraclavicular level (technique by Kulenkampff) Introduction The first percutaneous supraclavicular technique14 was described by Kulenkampff in 1911. Its typical characteristic is the high efficiency rate when approaching the brachial plexus at a point where the three trunks dispose in compact form; it is also the boarding route with which fewer nerves are missed. The administration of a small volume of local anesthetic will produce a more complete blockade of lower latency and is effective for surgery of the arm, forearm, elbow, and hand with a single puncture.
Anatomy of the brachial plexus Regional anesthesia of the upper extremity requires complete and sound knowledge of the anatomy of the brachial plexus. This facilitates technical aspects of the blockade, increases effectiveness, and diminishes the rate of complications. For a complete anatomical review, we go back to the chapter on anatomy of the brachial plexus. Above the first rib, the three primary trunks are close together as in the narrowest part of a sandglass, which makes this blockade more predictable. The area where the solution is injected is limited by the subclavian artery inwards, the clavicle outwards and the first rib below. Another significant aspect is the different relationships that the plexus maintains at supraclavicular level
Equipment ● ● ● ● ● ● ● ● ● ● ● ● ●
●
Sterile compresses. Sterile gloves. One or two 20-mL syringes, one 10-mL syringe. Sterile pot for the local anesthetic solution. 23-gauge, 1-inch (2.5 cm) needle, 23-gauge butterfly. Extension. Neurostimulator. Electrode. 25-gauge needle for skin infiltration. 22-gauge, 2-inch insulated needle for neurolocalization. Adrenaline. Sodium bicarbonate: 1 molar. Local anesthetic. From 40 to 50 mL (lidocaine or mepivacaine to 1%, 1.5%, 2% with epinephrine. Bupivacaine to 0.25%, 0.5%). Tuberculine syringe.
Figure 1 Kulenkampff technique: Position of the patient the operator and direction of the needle.
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
with structures that can cause complications in the blockade: the phrenic nerve, the stellate ganglion, the cervical plexus and the pleural cupula, mainly.
Position of the patient The patient can be either sitting down as originally described by Kulenkampff14 or in the supine position, with a small pillow between both scapulas. The head rotated toward the contralateral side. In this position, the plexus, which is leaning on the first rib, becomes more superficial. The arm15 is placed in abduction with a moderate traction toward the knee, for better identification of anatomical references. The midpoint of the clavicle, the beat of the subclavian artery and the spinous process of D2 should be identified and marked.
Technique ● ● ●
●
The anesthesiologist (Figure 1) stands at the same side of the extremity to be blocked. The beat of the subclavian artery is located by means of palpation. The midpoint of the clavicle is marked. This is usually located in the intersection of a projection of the itinerary of the external jugular vein with the clavicle. Then, a wheal of local anesthetic is performed exactly above the beat of the subclavian artery or, if the beat were not palpable, 2 cm toward cephalic from the midpoint of the clavicle.
Paresthesia technique1 ● ●
●
●
●
A 22- or 23-gauge, 2.5-cm needle attached to an extension is used. Direction of the needle should be backwards, downwards, and inwards, as if pointing the tip of the needle toward the spinous process of the second dorsal vertebra (D2). Needle is advanced slowly, until a paresthesia is elicited. Here, progression is stopped. The paresthesia is usually reported by the patient as “reaching the tip of the fingers.” It is of electric characteristics and quite unpleasant. It can also be reported as “pain.” The tip of the needle is withdrawn a millimeter and, prior to negative blood aspiration, the total volume of LA is injected. It is not uncommon for the patient to report a paresthesia by pressure, which should be differentiated from an intraneural injection. Onset is very quick; however, one should wait for about 20 minutes until sensitive blockade is completed.
Technique with peripheral nerve stimulator4 ● ●
A 22- or 24-gauge insulated needle is used, depending on the thickness of the neck. One begins at an intensity of 1 mA, a duration of 0.1 msec, and a frequency of 2 Hz, searching for an appropriate motor response (MR). Namely, Grade II contraction of the fingers and hand, corresponding to the median nerve (middle trunk).
97 ● ● ●
● ●
●
From 20 to 30 mL of anesthetic solution is injected, aspiring every 5 mL to avoid intravascular injection. Either lidocaine or mepivacaine to 1.5% with epinephrine is used for surgery, or combinations with bupivacaine. Originally, Kulenkampff pointed out that the goal was to reach the nerve trunks instead of the first rib. He stated that the latter functioned as a barrier against contact with the pleura. In the absence of paresthesia, MR, or contact with the first rib, the needle has to be redirected toward posterior. If there is return of arterial blood in the puncture, this means the tip of the needle is located too anterior. One should withdraw the needle, press during several minutes and, then, redirect the needle toward posterior. Remember that the first rib has anterior–posterior direction instead of lateral–medial (like a chain hanging from the neck). If we move away from it toward medial, we will make contact with the pleural cupula. The fact of obtaining a MR before a paresthesia gives relative security with the neurostimulator.16 This has revitalized this technique.
Advantages ● ●
It produces complete blockade of the upper extremity, which is of better quality and lower latency. Less volume of anesthetic can be injected.
Disadvantages ● ● ●
It requires a cooperative patient. If practiced by nonskilled hands, it is an inappropriate technique for ambulatory surgery. It is contraindicated for patients with pulmonary pathologies.
Complications17-21 Pneumothorax It is the most serious complication of this block. An incidence rate between 0.5% and 6.1% has been reported. Risk decreases with experience of the operator, use of short needles, and sound knowledge of the region’s anatomy. In addition, the puncture must be executed in aspiration. Special care should be exercised with thin tall patients. One should be suspicious when the patient reports thoracic pain, dyspnea, or cough. Diagnosis is confirmed by means of a thorax x-ray. Most pneumothorax require 24 hours to develop; they range from small to moderate size and do not usually cause symptoms. A lower percentage of pneumothorax appear within a few hours. These are usually extensive and accompanied by symptoms. Treatment depends on its magnitude and symptoms. In precocious and large pneumothorax, a pleural drainage should be practiced. Those of smaller degree are only drained if symptoms are evidenced. Hemidiaphragmatic paralysis Incidence is low in supraclavicular blockades. It is smaller than in interscalene blockade and is not associated with either symptoms or changes in breathing function.
98
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006
Nervous lesion Although paresthesia-seeking implies a certain degree of direct trauma on the nerve, the risk of nervous lesion can be more related to the use of long bevel needles, seeking more than one paresthesia, and appearance of severe pain during injection of local anesthetic (intraneural). Intravascular injection The vicinity of the brachial plexus to vascular structures contributes to intravascular injection. Frequent aspiration and strict monitoring are essential. Hematoma It usually has few consequences. Special care should be exercised in patients with clotting dysfunctions where blockade is contraindicated.
● ● ● ● ● ● ● ● ●
●
Conclusions It is a single puncture technique, ideal for arm, forearm, elbow, and hand surgeries. As approaching of the plexus is performed where the three nervous trunks are in a more compact form, they can be blocked with less volume of local anesthetic than the one necessary for other techniques, hence providing an excellent blockade of lower latency. Modifications to the technique as time went by, such as “walk” the first rib, increasing the number of punctures, and the volume of injection, only increased the number of complications. Neurolocalization has given new life to this technique. Today it is another alternative at supraclavicular level for brachial plexus blockade in upper extremity surgeries.
● ●
●
●
Low interscalene blockade (technique by Hadzic and Vloka22) Introduction The authors prefer this approach to the classic approach by Winnie. They argue that their selected interscalene space in the puncture site is not only wider but easier to identify. This blockade is performed immediately above the clavicle, in the same supraclavicular space as for subclavian perivascular blockades, Kulenkampff blockade, parascalene blockade, and the “plumb-bob” technique. Differences among variants of immediate supraclavicular blockades are minimal. The major difference is in the direction of the needle. Each of these techniques has its pros and cons. The final choice is a matter of personal preference. There are no comparative works among techniques yet.
Technique ● ● ●
It is performed with a neurostimulator. For the direction of the needle, it is convenient to use a shorter one (1 inch, 2.5 cm). Patient without pillow, prone position, light sedation, standard ASA monitoring, IV line.
Identify cricoid cartilage (C6). Ask the patient to rotate the head slightly toward the opposite side. The patient should try to touch his/her knee with the hand and relax the arm and shoulder. Then, he/she should lift the head. Two bundles (clavicular and sternal) of the sternocleidomastoid muscle are identified. The soft flesh of the index and major fingers are placed below the clavicular bundle at the height of C6. At this point, the patient is asked to relax the head. Next, the operator slightly rolls the fingers from the anterior scalene toward the middle scalene muscles. Descend the fingers leaning on the border of the middle scalene until the distal finger contacts the clavicle or the beat of the subclavian artery is identified (the lowest possible in the interscalene furrow). Place the major or annular finger on the beat of the artery (Figure 2). Insert the needle parallel to all planes and slightly toward caudal, between both fingers. Advance slowly according to technique, until obtaining the sought MR at 2 Hz, 0.5 mA, and 0.1 msec. The direction of the needle is incorrect if, after surpassing 1.2 inches in length, there has been no MR. Then, the needle should be withdrawn and the tip reoriented, not toward caudal or cephalic, but toward anterior or posterior, preferably. The motor response of the median nerve is the best [middle trunk: response of the hand, flexion of the fingers and wrist (median), or extension of the fingers (radial)]. Responses of the musculocutaneous and deltoids (superior trunk) are frequently elicited. From 30 to 40 mL of LA is injected, that is lidocaine or mepivacaine to 1.5%, or 30 mL to 2% with epinephrine for surgery and bupivacaine to 0.25% without epinephrine for postoperative analgesia:. If quick onset and prolonged anesthesia are sought, we use combinations of 15 mL bupivacaine to 0.5% ⫹ 15 mL lidocaine 2% with epinephrine.
Complications ● ●
Possible pneumothorax. Paralysis of the phrenic nerve.
Posterior approach of the brachial plexus (Pippa’s technique) Introduction and history The posterior approach with peripheral nerve stimulator (PNS) is very popular in Holland for shoulder surgery.23 This technique is indicated when the typical access cannot be performed and the patient must receive an interscalene blockade (local infections). Kappis, in 1912, and Santoni, in 1916, described a posterior approach of the brachial plexus, but it required multiple punctures.14 Pippa and coworkers revitalized this posterior boarding using a loss of resistance technique with a single injection.24
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
Figure 2
Hadzic and Vloka technique: Position of the operator’s fingers and direction of the needle.
Technique ●
●
●
● ●
99
The patient is placed in the sitting position with the head flexed. In young, anxious, or vagotonic patients, blockade can be made in the lateral position with the side to be blocked upwards. In the maximum flexion of the head, the seventh cervical vertebra is the most prominent one and the spinous process is marked. The spinous process of C6 is marked above the mark of C7. When the head is extended, this process moves forward and C7 remains as prominent (Figure 3). From the midpoint between the marks of C6 and C7, a 3.5- to 4-cm horizontal line is traced toward lateral. The end of this line is the needle insertion point (Figure 4). The PNS is connected at 2 Hz; 0.1 ms; 1 mA. A 10-cm insulated needle is inserted and sagittally directed, pointing toward the highest part of the cricoid cartilage. Do not go to medial plane (Figure 5).
●
● ● ●
●
At a depth of 5 to 6 cm, either contact is made with the transverse process of C7 or the needle passes between the transverse processes of C7–C6. If contact with the transverse process of C7 is made, the needle is withdrawn and redirected toward cephalic. At a depth of approximately 6 to 7 cm, muscular contractions to the brachial plexus are obtained. Intensity is diminished to 0.5 mA. Grade II MRs of the shoulder and/or arm should continue. After aspiration, a test dose of 2 mL of local anesthetic is injected. The response disappears and there should be no pain. The total volume of local anesthetic is fractionally injected.
Local anesthetic drugs ●
30 to 40 mL of LA is enough.
100
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006
Figure 5 Needle is inserted and sagittally directed, pointing toward the highest part of the cricoid cartilage.
Adverse effects and complications
Figure 3 The spinous process of C6 is marked above the mark of C7. When the head is extended, this process moves forward and C7 remains as prominent.
Short procedures ●
Lidocaine or mepivacaine to 1.5% with 1:200.000 epinephrine.
Prolonged procedures ● ●
●
Bupivacaine to 0.5%, or ropivacaine to 0.75%. Other authors use 30 to 40 mL of ropivacaine to 0.75% for ambulatory shoulder surgery.25 The time of onset is 5 to 10 minutes and duration of analgesia from 12 to 15 hours. The patients can go home safely, with the arm in a sling and clear instructions.
Advantages ● ● ●
Dagli and coworkers26 found around 35% reduction in all functional breathing tests due to 100% of hemidiaphragmatic paralysis produced. Rucci and coworkers27 compared the area of analgesia of the classic technique by Winnnie to the posterior approach and found that the analgesia area was different. The cervical plexus is not usually blocked with the posterior approach, whereas with the lateral approach blockade is achieved.
Anatomical references are clear and the technique is simple. The needle only goes through muscular planes, which reduces complications. This approach has a high rate of success based on experience and correct execution of the technique.
Subclavian perivascular blockade of the brachial plexus Introduction and history In 1964, it was described by Winnie and Collins.6 It is also known as Low Interscalene Blockade, as well as the technique by Vloka and Hadzic described in this chapter. This blockade is performed in the supraclavicular fossa immediately above the clavicle. The puncture site coincides with that of other techniques in that area, what varies is the direction of the needle that, in this approach, moves away from the pleural cupula. The puncture is at trunks’ level, which is the most compact point of the plexus. A smaller volume of local anesthetic (30 mL) than with the classic interscalene technique can be used. The advantage of this technique is that the needle accesses the fascia in its maximum diameter. On the contrary, other techniques access the fascia in its minimum diameter.
Technique ●
Figure 4 At 3.5- to 4-cm an horizontal line is traced toward lateral. At the end of this line is the needle insertion point.
It can be performed either as described in the original technique with search for a fascial “click,” trying to
Figure 6 Index finger on the beat of the subclavian artery in the supraclavicular fossa.
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
101 one produced by 50 mL in the axillary perivascular space. As the volume injected in the subclavian perivascular fossa is increased, distribution toward cephalic with cervical plexus and circumflex nerve blockades increases.
Complications30 ● ● ● ● ●
Figure 7 Subclavian perivascular technique: Position of the patient the operator and direction of the needle.
Possible pneumothorax. Phrenic nerve paralysis. Recurrent laryngeal paralysis. 25% of arterial puncture. 20% of hematomas.
Parascalene brachial plexus block Introduction and history
● ● ● ● ● ● ● ●
●
● ●
● ●
elicit a paresthesia or with neurostimulator as Franco and Winnie28 do at the moment. Patient is in the prone position, without a pillow under the head or between the scapulas. Identify cricoid cartilage (C6). Ask the patient to rotate the head slightly toward the opposite side and try to touch his/her knee with the hand. The patient should relax the arm and shoulder and lift the head. Both bundles (clavicular and sternal) of the sternocleidomastoid muscle are identified. The soft flesh of the index and major fingers are placed below the clavicular bundle at C6 level. The patient is asked to relax the head. Next, the fingers are slightly rolled from the anterior scalene toward the middle scalene. Do not press hard in this point because it can be unpleasant and/or painful. Descend with fingers leaning on the border of the middle scalene until the beat of the subclavian artery is identified (the lowest possible in the interscalene furrow). Place the index finger on the beat of the artery (Figure 6). Introduce the needle with the shaft as parallel as possible to the skin, in caudal direction. The tip of the needle is directed backwards the beat of the subclavian artery, which is below the index finger of the other hand. Do not go toward medial, following as parallel as possible the same direction as the scalene muscles, which go from the transverse process toward the first rib (Figure 7). Paresthesias of the median nerve are the best (middle trunk), tingling or electric sensation in the index finger.29 With PNS, try to produce a response of the hand, flexion of the fingers and wrist (median) or extension of the fingers (radial) at ⬍0.5 mA and 0.1 msec.
If the pulse of the artery is not palpable in the supraclavicular space, Franco and Winnie suggest that insertion of the needle should be made at a point determined by the transport of the width of the clavicular bundle toward lateral, and a finger slant toward cephalic. Direction of the 22-gauge insulated needle is similar to that of the original technique. ●
25 to 30 mL of LA in the subclavian perivascular fossa produces a motor and sensitive blockade similar to the
The original description of this technique was published in 1979 by Vongvises.31 In 100 cases, he highlighted the easy localization of surface anatomical references and the absence of pneumothorax as the main advantages of this approach. With the purpose of defining the position of the needle in relation to the pleural cupula, this author32 performed a study with tomographic cuts and determined that the level of needle insertion in the parascalene blockade is higher than the level of the pleural cupula (from 0.5 to 1.5 cm). In our country, this approach has been used since the early 1980s by anesthesiologists from the Military Central Hospital,33 and the experience with this approach in 100 patients has been published.34 Its use has also spread in Spain. There, Monzo accumulated great experience with this approach on arthroscopic shoulder surgery.35-37 Dalens describes his experience with the approach by Vongvises. However, he modified its use in children38,39 with PNS. The child is positioned in the supine position, and the puncture site is located in the union of the lower third with the two upper thirds of a line that joins the transverse process of C6 to the midpoint of the clavicle. Except for this difference in the puncture site, the technique is similar to the parascalene approach by Vongvises. This modification is due to anatomical principles because the pleural cupula is at a higher level in children.
Technique ●
●
● ● ●
The patient is in dorsal decubitus without pillows, with the arm to be operated extended at the side of the body, the shoulder downwards, with slight sedation. Anatomical references of the supraclavicular triangle are identified, ie, the posterior border of the sternocleidomastoid muscle, the clavicle, and the anterior border of the trapezius. The patient is asked to slightly rotate the head toward the opposite side. He/she is asked to try to touch his/her knee with the hand, descend the shoulder, and be relaxed. By lifting the head, the two bundles (clavicular and sternal) of the sternocleidomastoid muscle are identified.
102
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006 negative aspiration, the anesthetic solution in increasing fractional volumes of 5 mL. Aspiration among infiltrations is repeated to avoid inadvertent intravenous injection. ●
●
●
Figure 8
Parascalene technique: Patient’s position. ●
●
● ●
● ●
● ●
● ●
●
●
With the soft flesh of the index and major fingers below the clavicular bundle, one palpates the interscalene furrow located outside the posterior border of the sternocleidomastoid muscle. We then descend palpating until the beat of the subclavian artery is found in the vicinities of the clavicle. Certain maneuvers can be performed to make the interscalene space evident. They include: deep inspiration on the part of the patient, lateralization of the head toward the side of the puncture, observation or palpation of the beat of the subclavian artery in the supraclavicular space, etc.40 The key is accurate identification of the lateral border of the anterior scalene. Entrance to the sheath surrounding the plexus can be evident by means of the perception of a click, paresthesia, or motor response to neurostimulation. Skin antisepsis with iodized alcohol or iodopovidone. A dermic wheal is performed with a 25-gauge needle with lidocaine to 1% with 1:200.000 epinephrine in the puncture site, which is 1.5 to 2 cm above the clavicle in the lateral border of the anterior scalene above the subclavian artery and inside the external jugular vein (Figure 8). The authors suggest the use of the neurostimulator with an insulated needle of equal size. We continue using the immobile needle technique with an assistant who carries out the maneuvers with the PNS and injects the anesthetic solution. The needle is inserted in the interscalene groove in anteroposterior direction, ie, the needle tip perpendicularly directed to the plane of the stretcher. Progression is slow until achieving a depth of about 1 to 1.5 cm (Figure 9). In the case of paresthesia technique, the appropriate response must be located either in the shoulder, elbow, or hand. These responses are generally brief, light, and soft. A paresthesia toward posterior (suprascapular) can be elicited; in this case, it is necessary to redirect the needle toward anterior. If the paresthesia is anterior (thorax), the needle should be redirected backwards. If a PNS is available, a motor response is sought in the same areas.
When we obtain contraction of biceps or deltoid muscles with an equal or inferior stimulus than 0.5 mA, a duration of 0.1 msec, and a frequency of 2 Hz, we inject, prior to
If response to PNS is contraction of the diaphragm, we are topographically on the body of the anterior scalene; thus, we should withdraw the needle and reinsert it closer to the median scalene. In general, we obtain a motor response before inserting the needle 1.5 cm deep even in patients with voluminous necks. If the needle goes deeper in, the puncture site should be reconsidered. If the immobile needle technique41 has been adequately followed, we should not worry about the pavilion of the needle coming closer to the tissues since as we apply the injection a supraclavicular “tumor” due to distension of the prevertebral fascia is formed. In the first minutes following injection, tingling or heat sensations appear with impossibility of lifting the arm. A movement such as the one made when “counting money” may also be observed.
Adverse effects and complications Among complications of this approach are: ● ●
Possibility of vascular puncture. Claude Bernard Horner’s syndrome (which predicts success of the blockade). This syndrome disappears when blockade is reverted.
Figure 9
Parascalene technique: Needle direction.
Bollini et al
Figure 10 references.
● ●
●
Supraclavicular Blocks of the Brachial Plexus
Dupre and Danel technique: Anatomical surface
Blockade of the inferior laryngeal nerve with bitonal voice or hoarseness (less frequent). As there are no prospective studies on the incidence of homolateral phrenic nerve paralysis associated with this blockade, we are unable to state whether the incidence is lower than the one associated with the interscalene blockade described by Winnie. Although we consider that the parascalene approach is not ideal for placement of catheters due to perpendicular entrance to the major axis of the plexus, Monzo37 describes placement of catheters for shoulder surgery.
103
Figure 12 Plumb bob: Insertion point is located 1 to 2 cm from the clavicle toward cephalic, tangentially to the lateral border of the sternocleidomastoid muscle.
Cutaneous repairs ● ● ●
Technique ●
●
Supraclavicular technique by Dupré-Danel38 Introduction This technique is also known as “the surface reference” technique. The authors propose a tangential boarding of the plexus that facilitates placement of catheters. Unlike in other techniques, they use an 18-gauge, 5-cm insulated needle and a 20-gauge catheter.
Figure 11
Injection point and direction of the needle.
A: External jugular. B: Apex of Sedillot triangle (it is given by the union of both bundles of the sternocleidomastoid muscle. C: Internal border of the clavicular insertion of the clavicular fasciculus of the trapezius (Figure 10).
● ●
The patient is asked to lift the head from the plane of the stretcher in slight rotation toward the contralateral side to make anatomical references evident. A line is drawn from the cephalic vertex of the Sedillot triangle to the medial border of the clavicular insertion of the trapezius. The itinerary of the external jugular vein is marked (dotted line in Figure 10). The injection point is marked at the intersection of the line of the lateral border of the external jugular vein with the line drawn between the apex of the triangle and the medial insertion of the trapezius in the clavicle. The axis of the puncture goes through the outer ear (Figure 11).
Figure 13 direction.
The needle is advanced in a strict anteroposterior
104
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006 from the approach proposed by Brown is that a lower and more medial puncture site is used, which, from our standpoint, increases the risk of puncture of the pleural cupula.
Intersternocleidomastoid technique Introduction
Figure 14 tion. ●
Intersternocleidomastoid technique: Needle direc-
The usual motor response is that of the triceps. Contraction of the biceps is also an excellent response. The puncture is 1 to 2.5 cm deep, and 30 mL of anesthetic solution is injected. The catheter is 2 cm deep.
In 1997, Pham-Dang13 described a really novel supraclavicular boarding. It was called the intersternocleidomastoid technique, and it was based on a previous anatomical study on cadavers. It stresses the simplicity of the references to keep in mind: the triangle formed by both heads of the sternocleidomastoid muscle and the clavicle, usually visible and palpable in most patients.
Technique ●
●
Plumb-bob technique ●
Introduction This technique was described by Brown.42,43 It shares the position, indications, and volume of local anesthetics with the parascalene technique. The only difference is given by the entrance point of the needle.
Technique ●
●
● ●
●
The lateral border of the sternocleidomastoid muscle should be identified at the level of its insertion in the clavicle. This becomes evident by asking the patient to lift the head from the bed. A 5- to 6-cm blunt needle is inserted in an exact perpendicular and parasagittal plane to the patient and the stretcher (the horizontal one). The insertion point is located 1 to 2 cm from the clavicle toward cephalic, tangentially to the lateral border of the sternocleidomastoid muscle (Figure 12). The needle is advanced in a strict anteroposterior direction (Figure 13). If no contact is made with the first rib or if a paresthesia is not elicited, direction of the needle tip should be modified toward cephalic until a maximum 30° angle is achieved. If paresthesia is not obtained, the needle is redirected toward the feet up to a maximum 30° angle, until either a paresthesia is elicited or the first rib is found.44 The possibility of a pneumothorax increases in this last maneuver if performed by nonskilled hands. With regard to the classic description by Vongvises,31 the only similarity is the anteroposterior (perpendicular to the stretcher) direction of the needle. The difference
●
● ●
● ●
The patient rests in the supine position with the head rotated contralateral to the site of the blockade and with the arm at the side of the body. The triangle formed by both bundles of the sternocleidomastoid muscles and the clavicle is identified. The midpoint is marked. The puncture site is located in the internal border of the clavicular bundle, at two finger’s slant (3 cm) above the sternum. The neurostimulation needle is directed toward caudal, dorsal, and laterally to the midpoint of the clavicle, going below the muscular stomach of the sternocleidomastoid muscle, forming a 40° to 50° angle with the operating table (Figure 14). The plexus is located at a depth of 5 to 7 cm. The muscular responses obtained are those of the radial and musculocutaneous nerves. The latter is the most frequent initial response. 30 mL of LA is injected when the intensity is of 0.5 mA. If the phrenic nerve is stimulated (which is evident by contractions of the diaphragm), the needle is slightly redirected toward lateral.
Although we lack experience with this approach, we should highlight the potentiality of lesions either of the phrenic nerve or of the large vessels of the neck (internal jugular, carotid). In our opinion, this technique does not have outstanding advantages over other approaches.
References 1. Kulenkampff D: Die Anästhesierung des plexus brachialis. Beitr Klin Chir 79:550-552, 1912 2. Lanz E, Theiss D, Jankovic D: The extent of blockade following various techniques plexus block. Anesth Analg 62:55-58, 1983 3. Dupré LJ: Blocking of the brachial plexus: which techniques should be chosen? Cahiers d’Anestesiologie 43:587-600, 1995 4. Pande R, Pande M, Bhadani U, et al: Supraclavicular brachial plexus block as a sole anesthetic technique in children: an analysis of 200 cases. Anesthesia 55:798-802, 2000
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
5. Mak PH, Irwin MG, Ooi CG, et al: Incidence of diaphragmatic paralysis following supraclavicular brachial plexus block and its effect on pulmonary function. Anesthesia 56:352-356, 2001 6. Winnie A, Collins V: The subclavian Perivascular technique of brachial plexus anesthesia. Anesthesiology 25:353-363, 1964 7. Vongvises P, Panijayanond T: A parascalene technique of brachial plexus anesthesia. Anesth Analg 58:267-273, 1979 8. Dupré JL, Danel V, Legrand JJ, et al: Surface landmarks for supraclavicular block of the brachial plexus. Anesth Analg 61:28-31, 1982 9. Brown DL, Bridenbaugh LD: Physics applied to regional anesthesia results in an improved supraclavicular block: the “plumb bob” technique. Anesthesiology 69:A376, 1988 10. Moorthy SS, Schmidt SL, Dierdorf SF: A supraclavicular lateral paravascular approach for brachial plexus regional anesthesia. Anesth Analg 72:241-244, 1991 11. Pippa P, Cominelli E, Marinelli C, et al: Brachial plexus block using the posterior approach. Eur J Anaesthesiol 7:411-420, 1990 12. Ortells-Polo MA, García-Guiral M, García-Amigueti FJ, et al: Anestesia del plexo braquial: resultados de una técnica supraclavicular perivascular modificada. Rev Esp Anestesiol Reanim 43:94-98, 1996 13. Pham-Dang C, Gunst JP, Gouin F, et al: A novel supraclavicular approach to brachial plexus block. Anesth Analg 85:111-116, 1997 14. Winnie AP: Anestesia de Plexos Técnicas Perivasculares de bloqueo del Plexo Braquialqq. Salvat, Barcelona, Salvat, 1986, pp 68-75 15. Winnie AP, Franco CD: Supraclavicular approaches to brachial plexus anesthesia. Tech Reg Anesth Pain Manage 1:144-150, 1986 16. Bollini CA, Urmey W, Vascello L, et al: Relationship between evoked motor response and sensory paresthesia in interscalene brachial plexus block. Reg Anesth Pain Med 28:384-388, 2003 17. Cousins MJ, Bridenbaugh PO: Neural blockade in clinical anesthesia and management of pain, second edition. Philadelphia, PA, J.B. Lippincott Company, 1988, pp 387-417 18. Neal JM, Hebe JR, Gerancher J, et al: Brachial plexus anesthesia essentials of our current understanding. Reg Anesth Pain Med 27:402428, 2002 19. Peláez X, Ornaque I: Bloqueo supraclavicular, in Anestesia Regional Hoy (2° Edición). Capitulo 17:265-280, 2001 20. Brown DL, Cahill DR, Bridenbaugh D: Supraclavicular nerve block: anatomic analysis of a method to prevent pneumothorax. Anesth Analg 76:530-534, 1993 21. Bollini CA: Actas de V congreso Sudamericano y XXVII Congreso Argentino de Anestesiología, Iguazú Misiones, pp 171 y col, 1998 22. Hadzic A, Vloka JD: Peripheral Nerve Blocks Principles and Practice, New York, NY, McGraw Hill, 2004, pp 108-122 23. Jack NTM, Stienstra R: Anesthesie van de plexus brachialis: ervaringen met de posterieure benadering. Ned T Anesthesiol 11:50-52, 1998 24. Rettig HC, Gielen MJ, Jack NT, et al: A comparison of the lateral and posterior approach for brachial plexus block. Reg Anesth Pain Med 3:119-126, 2006
105 25. Neal JM, Hebl JR, Gerancher JC, et al: Brachial plexus anesthesia: essentials of our current understanding. Reg Anesth Pain Med 27:402428, 2002 26. Dagli G, Guzeldemir ME, Volkan Acar H, et al: The effects and side effects of interscalene brachial plexus block by posterior approach. Reg Anesth Pain Med 23:87-91, 1998 27. Rucci FS, et al: How many interscalene blocks are there? A comparison between the lateral and posterior approach. Eur J Anaesthesiol 10:303-307, 1993 28. Franco C, Winnie A: Subclavian perivascular block with a nerve stimulator: outcome study after 1000 blocks. RAPM 24, 1999 29. Hickey R, Garland TA, Ramamurthy S: Subclavian perivascular block: influence of location of paresthesia. Anesth Analg 68:767-771, 1989 30. Wikinski J, Bollini C: Complicaciones neurológicas de la anestesia regional periférica y central. Panamericana. 51-53, 1999 31. Vongvises P, Panijayanond T: A parascalene technique of brachial plexus anesthesia. Anesth Analg 58:267-273, 1979 32. Vongvises P: Beokhaimook Computed tomographic study of parascalene block. Anesth Analg 842:379, 1997 33. Fernandez RO, Sanchez WJ: Nuestra experiencia con una nueva técnica de bloqueo del plexo braquial paraescalénica. Prensa Med Argent 69:890, 1982 34. Salgueiro C, de la Peña R: Experiencia clínica con el abordaje paraescalénico para el bloqueo del plexo braquial Indicaciones, ventajas y complicaciones. Rev Arg Anest 54:322-327, 1996 35. Monzó E, Baeza C, Sánchez ML, et al: Bloqueo paraescalénico continuo en la cirugía del hombro. Rev Esp Anestesiol Reanim 45:377383, 1998 36. Call Reigl L, de Vicente Sole J, Estany Raluy E: Parascalene block for shoulder arthroscopy surgery. Rev Esp Anestesiol Reanim 51:247252, 2004 37. Monzo Abad E, Baeza Gil C, Galindo Sanchez F, et al: Parascalene brachial plexus block: experience of 10 years. Rev Esp Anestesiol Reanim 512:61-69, 2004 38. Dupré JL, Danel V, Legrand JJ, et al: Surface landmarks for supraclavicular block of the brachial plexus. Anesth Analg 61:28, 1982 39. Dalens B, Vanneuville G, Tanguy A: A new parascalene approach to the brachial plexus in children: comparison with the supraclavicular approach. Anesth Analg 66:1264-1271, 1987 40. Bollini CA: Una Maniobra útil para identificar el espacio interescalénico. Rev Arg Anest 55:310-312, 1997 41. Winnie AP: An immobile needle for nerve blocks. Anesthesiology 31:577, 1969 42. Brown DL: Regional Anesthesia and Analgesia. Philadelphia, PA, W.B. Saunders Company, 1996, p 265 43. Brown DL: Atlas of Regional Anesthesia (ed 2). Philadelphia, PA, WB Saunder Company, 1999 44. VadeBoncouer TR, Weinberg GL: Supraclavicular brachial plexus anesthesia using the plumb bob method. Tech Reg Anesth 1:151-156, 1997
Supraclavicular blocks of the brachial plexus Carlos A. Bollini, MD, Fernando Cacheiro, MD, Carlos Salgueiro, MD, Miguel Moreno, MD From the Servicio de Anestesia del Instituto Argentino de Diagnostico y Tratamiento, Capital Federal, Argentina; the Servicio de Anestesia del Hospital Municipal “Juan A. Fernandez,” Capital Federal, Argentina; and the Servicio de Anestesia del Hospital Universitario Austral, Pilar, Buenos Aires, Argentina. KEYWORDS: Supraclavicular; Brachial plexus; Regional anesthesia
The concept of a continuous perineural and perivascular space surrounding the brachial plexus from roots to terminal nerves, allows the injection of a local anesthetic at any level from the neck to the axilla. A complete anesthesia of the entire upper extremity can be simple, safe and effectively provided by blocking the brachial plexus using any supraclavicular approach. At the supraclavicular fossa the plexus is most compactly arranged and local anesthesia is delivered at the trunks level. The different approaches described, can be performed with the upper extremity in any position especially in those patients not suitable for an axillary block. All the supraclavicular approaches offer a high success rate and avoid the sparing of the ulnar nerve with the interscalene technique and the musculocutaneous often missed with the axillary block. All these approaches carry a greater risk of pneumothorax. With the use of the peripheral nerve stimulator, the old Kulenkampff technique is now in a period of renaissance. © 2006 Elsevier Inc. All rights reserved.
These blockades include all those approaches of the brachial plexus that are performed immediately above the clavicle. They can be classified into supraclavicular techniques strictly so-called, low interscalene and parascalene. Supraclavicular blockades provide, with a single injection, complete anesthesia of the upper extremity. Most of these techniques were originally described with the purpose of reducing pneumothorax incidence. Pneumothorax is a feared complication typically associated with classic supraclavicular blockade by Kulenkampff.1 By any of these routes, one can achieve appropriate surgical blockade of the upper extremity. However, supraclavicular injection of the local anesthetic produces a quicker and more homogeneous blockade. The point of injection anatomically coincides with the site where all the trunks are grouped among themselves (sandglass narrowing). This site includes nerves, such as the circumflex and musculocutaneous ones, that have not left the sheath yet. This is the reason why such nerves will be difficult to block with lower routes. Therefore, supraclavicular approaches have been proposed as the
Address reprint requests and correspondence: Carlos A. Bollini, MD, J.D. Peron 2375, 1629 Pilar, Buenos Aires, Argentina. E-mail address: [email protected]. 1084-208X/$ -see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1053/j.trap.2006.07.010
most effective and uniform procedures for the entire brachial plexus.2,3
History Multiple approaches of the brachial plexus above the clavicle have been described. The first and best known is the classic supraclavicular by Kulenkampff.1 Although it seemed to have fallen into disuse, recent publications support its popularity4,5 due to the use of the neurostimulator. After this approach, many others appeared. Among them are: the subclavian perivascular by Winnie,6 the parascalene by Vongvises and Panijayanond,7 the one by Dupré and Danel,8 the “plumb-bob” approach by Brown,9 the supraclavicular lateral paravascular by Moorthy,10 the posterior approach by Pippa,11 the supraclavicular perivascular modified by Ortells-Polo,12 and the intersternocleidomastoid by PhamDang,13 among many others.14 The great diversity of techniques with minimum variants supports the idea that none of them is the perfect technique or is exempt from potential risks. In fact, cases of major complications have been published with almost every technique. They include: pneumothorax, radicular lesion, medullary lesion, vascular puncture (vertebral, subclavian, jugular), subarachnoid or epidural
96
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006
injection, acute breathing insufficiency, cardiovascular collapse, bilateral blockade, bronchospasm, unconsciousness, apnea, etc. However, the techniques of supraclavicular approach are, beyond any doubt, the most effective techniques. They will provide the best quality, consistency, and shortest waiting time of brachial plexus blockade for the entire upper extremity. With these procedures, the local anesthetic acts at the level of the trunks and divisions of the brachial plexus. These boarding routes allow blockade of the higher number of nerves that originate in this plexus, provided paresthesia or neurolocalization were effective. In case of using them for shoulder surgery, the cervical plexus that innervates the skin of the shoulder should be blocked separately, even in the case of slight cephalic diffusion of LA. Although they are easy to execute, these techniques are difficult to teach and learn; maybe because all variants are circumscribed to a triangular surface of 5 cm and its anatomy and precise anatomical references can be easily confused in the absence of adequate practice.
Indications ●
● ● ● ●
●
Surgeries below the shoulder (arm, forearm, and hand). These techniques are very useful when access to the axilla is impossible regardless of the cause (tumor, infection, etc.). Shoulder surgery with appropriate complementation. Surgery of the elbow: fractures, arthroscopy, resection of the head of the radius. Transposition of the cubital nerve. The musculocutaneous and cubital nerves are blocked. However, in the axilla accessory to the internal brachial cutaneous, internal brachial cutaneous and intercostobrachial nerves must be supplemented. Preventive analgesia, treatment of postoperative pain in shoulder surgery, reduction of shoulder luxations, sympathetic blockade for reflex, sympathetic Dystrophy, causalgia, vascular surgery, Raynaud syndrome.
Preparation of patients before blockade Before any regional blockade, one should always settle a standard ASA monitor (EKG, blood pressure and saturation of O2), and an IV line in the contralateral upper extremity. Reanimation kit should be ready. For most supraclavicular techniques, we prefer light sedation with midazolam (from 0.01 to 0.02 mg/kg).
Brachial plexus blockade at supraclavicular level (technique by Kulenkampff) Introduction The first percutaneous supraclavicular technique14 was described by Kulenkampff in 1911. Its typical characteristic is the high efficiency rate when approaching the brachial plexus at a point where the three trunks dispose in compact form; it is also the boarding route with which fewer nerves are missed. The administration of a small volume of local anesthetic will produce a more complete blockade of lower latency and is effective for surgery of the arm, forearm, elbow, and hand with a single puncture.
Anatomy of the brachial plexus Regional anesthesia of the upper extremity requires complete and sound knowledge of the anatomy of the brachial plexus. This facilitates technical aspects of the blockade, increases effectiveness, and diminishes the rate of complications. For a complete anatomical review, we go back to the chapter on anatomy of the brachial plexus. Above the first rib, the three primary trunks are close together as in the narrowest part of a sandglass, which makes this blockade more predictable. The area where the solution is injected is limited by the subclavian artery inwards, the clavicle outwards and the first rib below. Another significant aspect is the different relationships that the plexus maintains at supraclavicular level
Equipment ● ● ● ● ● ● ● ● ● ● ● ● ●
●
Sterile compresses. Sterile gloves. One or two 20-mL syringes, one 10-mL syringe. Sterile pot for the local anesthetic solution. 23-gauge, 1-inch (2.5 cm) needle, 23-gauge butterfly. Extension. Neurostimulator. Electrode. 25-gauge needle for skin infiltration. 22-gauge, 2-inch insulated needle for neurolocalization. Adrenaline. Sodium bicarbonate: 1 molar. Local anesthetic. From 40 to 50 mL (lidocaine or mepivacaine to 1%, 1.5%, 2% with epinephrine. Bupivacaine to 0.25%, 0.5%). Tuberculine syringe.
Figure 1 Kulenkampff technique: Position of the patient the operator and direction of the needle.
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
with structures that can cause complications in the blockade: the phrenic nerve, the stellate ganglion, the cervical plexus and the pleural cupula, mainly.
Position of the patient The patient can be either sitting down as originally described by Kulenkampff14 or in the supine position, with a small pillow between both scapulas. The head rotated toward the contralateral side. In this position, the plexus, which is leaning on the first rib, becomes more superficial. The arm15 is placed in abduction with a moderate traction toward the knee, for better identification of anatomical references. The midpoint of the clavicle, the beat of the subclavian artery and the spinous process of D2 should be identified and marked.
Technique ● ● ●
●
The anesthesiologist (Figure 1) stands at the same side of the extremity to be blocked. The beat of the subclavian artery is located by means of palpation. The midpoint of the clavicle is marked. This is usually located in the intersection of a projection of the itinerary of the external jugular vein with the clavicle. Then, a wheal of local anesthetic is performed exactly above the beat of the subclavian artery or, if the beat were not palpable, 2 cm toward cephalic from the midpoint of the clavicle.
Paresthesia technique1 ● ●
●
●
●
A 22- or 23-gauge, 2.5-cm needle attached to an extension is used. Direction of the needle should be backwards, downwards, and inwards, as if pointing the tip of the needle toward the spinous process of the second dorsal vertebra (D2). Needle is advanced slowly, until a paresthesia is elicited. Here, progression is stopped. The paresthesia is usually reported by the patient as “reaching the tip of the fingers.” It is of electric characteristics and quite unpleasant. It can also be reported as “pain.” The tip of the needle is withdrawn a millimeter and, prior to negative blood aspiration, the total volume of LA is injected. It is not uncommon for the patient to report a paresthesia by pressure, which should be differentiated from an intraneural injection. Onset is very quick; however, one should wait for about 20 minutes until sensitive blockade is completed.
Technique with peripheral nerve stimulator4 ● ●
A 22- or 24-gauge insulated needle is used, depending on the thickness of the neck. One begins at an intensity of 1 mA, a duration of 0.1 msec, and a frequency of 2 Hz, searching for an appropriate motor response (MR). Namely, Grade II contraction of the fingers and hand, corresponding to the median nerve (middle trunk).
97 ● ● ●
● ●
●
From 20 to 30 mL of anesthetic solution is injected, aspiring every 5 mL to avoid intravascular injection. Either lidocaine or mepivacaine to 1.5% with epinephrine is used for surgery, or combinations with bupivacaine. Originally, Kulenkampff pointed out that the goal was to reach the nerve trunks instead of the first rib. He stated that the latter functioned as a barrier against contact with the pleura. In the absence of paresthesia, MR, or contact with the first rib, the needle has to be redirected toward posterior. If there is return of arterial blood in the puncture, this means the tip of the needle is located too anterior. One should withdraw the needle, press during several minutes and, then, redirect the needle toward posterior. Remember that the first rib has anterior–posterior direction instead of lateral–medial (like a chain hanging from the neck). If we move away from it toward medial, we will make contact with the pleural cupula. The fact of obtaining a MR before a paresthesia gives relative security with the neurostimulator.16 This has revitalized this technique.
Advantages ● ●
It produces complete blockade of the upper extremity, which is of better quality and lower latency. Less volume of anesthetic can be injected.
Disadvantages ● ● ●
It requires a cooperative patient. If practiced by nonskilled hands, it is an inappropriate technique for ambulatory surgery. It is contraindicated for patients with pulmonary pathologies.
Complications17-21 Pneumothorax It is the most serious complication of this block. An incidence rate between 0.5% and 6.1% has been reported. Risk decreases with experience of the operator, use of short needles, and sound knowledge of the region’s anatomy. In addition, the puncture must be executed in aspiration. Special care should be exercised with thin tall patients. One should be suspicious when the patient reports thoracic pain, dyspnea, or cough. Diagnosis is confirmed by means of a thorax x-ray. Most pneumothorax require 24 hours to develop; they range from small to moderate size and do not usually cause symptoms. A lower percentage of pneumothorax appear within a few hours. These are usually extensive and accompanied by symptoms. Treatment depends on its magnitude and symptoms. In precocious and large pneumothorax, a pleural drainage should be practiced. Those of smaller degree are only drained if symptoms are evidenced. Hemidiaphragmatic paralysis Incidence is low in supraclavicular blockades. It is smaller than in interscalene blockade and is not associated with either symptoms or changes in breathing function.
98
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006
Nervous lesion Although paresthesia-seeking implies a certain degree of direct trauma on the nerve, the risk of nervous lesion can be more related to the use of long bevel needles, seeking more than one paresthesia, and appearance of severe pain during injection of local anesthetic (intraneural). Intravascular injection The vicinity of the brachial plexus to vascular structures contributes to intravascular injection. Frequent aspiration and strict monitoring are essential. Hematoma It usually has few consequences. Special care should be exercised in patients with clotting dysfunctions where blockade is contraindicated.
● ● ● ● ● ● ● ● ●
●
Conclusions It is a single puncture technique, ideal for arm, forearm, elbow, and hand surgeries. As approaching of the plexus is performed where the three nervous trunks are in a more compact form, they can be blocked with less volume of local anesthetic than the one necessary for other techniques, hence providing an excellent blockade of lower latency. Modifications to the technique as time went by, such as “walk” the first rib, increasing the number of punctures, and the volume of injection, only increased the number of complications. Neurolocalization has given new life to this technique. Today it is another alternative at supraclavicular level for brachial plexus blockade in upper extremity surgeries.
● ●
●
●
Low interscalene blockade (technique by Hadzic and Vloka22) Introduction The authors prefer this approach to the classic approach by Winnie. They argue that their selected interscalene space in the puncture site is not only wider but easier to identify. This blockade is performed immediately above the clavicle, in the same supraclavicular space as for subclavian perivascular blockades, Kulenkampff blockade, parascalene blockade, and the “plumb-bob” technique. Differences among variants of immediate supraclavicular blockades are minimal. The major difference is in the direction of the needle. Each of these techniques has its pros and cons. The final choice is a matter of personal preference. There are no comparative works among techniques yet.
Technique ● ● ●
It is performed with a neurostimulator. For the direction of the needle, it is convenient to use a shorter one (1 inch, 2.5 cm). Patient without pillow, prone position, light sedation, standard ASA monitoring, IV line.
Identify cricoid cartilage (C6). Ask the patient to rotate the head slightly toward the opposite side. The patient should try to touch his/her knee with the hand and relax the arm and shoulder. Then, he/she should lift the head. Two bundles (clavicular and sternal) of the sternocleidomastoid muscle are identified. The soft flesh of the index and major fingers are placed below the clavicular bundle at the height of C6. At this point, the patient is asked to relax the head. Next, the operator slightly rolls the fingers from the anterior scalene toward the middle scalene muscles. Descend the fingers leaning on the border of the middle scalene until the distal finger contacts the clavicle or the beat of the subclavian artery is identified (the lowest possible in the interscalene furrow). Place the major or annular finger on the beat of the artery (Figure 2). Insert the needle parallel to all planes and slightly toward caudal, between both fingers. Advance slowly according to technique, until obtaining the sought MR at 2 Hz, 0.5 mA, and 0.1 msec. The direction of the needle is incorrect if, after surpassing 1.2 inches in length, there has been no MR. Then, the needle should be withdrawn and the tip reoriented, not toward caudal or cephalic, but toward anterior or posterior, preferably. The motor response of the median nerve is the best [middle trunk: response of the hand, flexion of the fingers and wrist (median), or extension of the fingers (radial)]. Responses of the musculocutaneous and deltoids (superior trunk) are frequently elicited. From 30 to 40 mL of LA is injected, that is lidocaine or mepivacaine to 1.5%, or 30 mL to 2% with epinephrine for surgery and bupivacaine to 0.25% without epinephrine for postoperative analgesia:. If quick onset and prolonged anesthesia are sought, we use combinations of 15 mL bupivacaine to 0.5% ⫹ 15 mL lidocaine 2% with epinephrine.
Complications ● ●
Possible pneumothorax. Paralysis of the phrenic nerve.
Posterior approach of the brachial plexus (Pippa’s technique) Introduction and history The posterior approach with peripheral nerve stimulator (PNS) is very popular in Holland for shoulder surgery.23 This technique is indicated when the typical access cannot be performed and the patient must receive an interscalene blockade (local infections). Kappis, in 1912, and Santoni, in 1916, described a posterior approach of the brachial plexus, but it required multiple punctures.14 Pippa and coworkers revitalized this posterior boarding using a loss of resistance technique with a single injection.24
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
Figure 2
Hadzic and Vloka technique: Position of the operator’s fingers and direction of the needle.
Technique ●
●
●
● ●
99
The patient is placed in the sitting position with the head flexed. In young, anxious, or vagotonic patients, blockade can be made in the lateral position with the side to be blocked upwards. In the maximum flexion of the head, the seventh cervical vertebra is the most prominent one and the spinous process is marked. The spinous process of C6 is marked above the mark of C7. When the head is extended, this process moves forward and C7 remains as prominent (Figure 3). From the midpoint between the marks of C6 and C7, a 3.5- to 4-cm horizontal line is traced toward lateral. The end of this line is the needle insertion point (Figure 4). The PNS is connected at 2 Hz; 0.1 ms; 1 mA. A 10-cm insulated needle is inserted and sagittally directed, pointing toward the highest part of the cricoid cartilage. Do not go to medial plane (Figure 5).
●
● ● ●
●
At a depth of 5 to 6 cm, either contact is made with the transverse process of C7 or the needle passes between the transverse processes of C7–C6. If contact with the transverse process of C7 is made, the needle is withdrawn and redirected toward cephalic. At a depth of approximately 6 to 7 cm, muscular contractions to the brachial plexus are obtained. Intensity is diminished to 0.5 mA. Grade II MRs of the shoulder and/or arm should continue. After aspiration, a test dose of 2 mL of local anesthetic is injected. The response disappears and there should be no pain. The total volume of local anesthetic is fractionally injected.
Local anesthetic drugs ●
30 to 40 mL of LA is enough.
100
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006
Figure 5 Needle is inserted and sagittally directed, pointing toward the highest part of the cricoid cartilage.
Adverse effects and complications
Figure 3 The spinous process of C6 is marked above the mark of C7. When the head is extended, this process moves forward and C7 remains as prominent.
Short procedures ●
Lidocaine or mepivacaine to 1.5% with 1:200.000 epinephrine.
Prolonged procedures ● ●
●
Bupivacaine to 0.5%, or ropivacaine to 0.75%. Other authors use 30 to 40 mL of ropivacaine to 0.75% for ambulatory shoulder surgery.25 The time of onset is 5 to 10 minutes and duration of analgesia from 12 to 15 hours. The patients can go home safely, with the arm in a sling and clear instructions.
Advantages ● ● ●
Dagli and coworkers26 found around 35% reduction in all functional breathing tests due to 100% of hemidiaphragmatic paralysis produced. Rucci and coworkers27 compared the area of analgesia of the classic technique by Winnnie to the posterior approach and found that the analgesia area was different. The cervical plexus is not usually blocked with the posterior approach, whereas with the lateral approach blockade is achieved.
Anatomical references are clear and the technique is simple. The needle only goes through muscular planes, which reduces complications. This approach has a high rate of success based on experience and correct execution of the technique.
Subclavian perivascular blockade of the brachial plexus Introduction and history In 1964, it was described by Winnie and Collins.6 It is also known as Low Interscalene Blockade, as well as the technique by Vloka and Hadzic described in this chapter. This blockade is performed in the supraclavicular fossa immediately above the clavicle. The puncture site coincides with that of other techniques in that area, what varies is the direction of the needle that, in this approach, moves away from the pleural cupula. The puncture is at trunks’ level, which is the most compact point of the plexus. A smaller volume of local anesthetic (30 mL) than with the classic interscalene technique can be used. The advantage of this technique is that the needle accesses the fascia in its maximum diameter. On the contrary, other techniques access the fascia in its minimum diameter.
Technique ●
Figure 4 At 3.5- to 4-cm an horizontal line is traced toward lateral. At the end of this line is the needle insertion point.
It can be performed either as described in the original technique with search for a fascial “click,” trying to
Figure 6 Index finger on the beat of the subclavian artery in the supraclavicular fossa.
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
101 one produced by 50 mL in the axillary perivascular space. As the volume injected in the subclavian perivascular fossa is increased, distribution toward cephalic with cervical plexus and circumflex nerve blockades increases.
Complications30 ● ● ● ● ●
Figure 7 Subclavian perivascular technique: Position of the patient the operator and direction of the needle.
Possible pneumothorax. Phrenic nerve paralysis. Recurrent laryngeal paralysis. 25% of arterial puncture. 20% of hematomas.
Parascalene brachial plexus block Introduction and history
● ● ● ● ● ● ● ●
●
● ●
● ●
elicit a paresthesia or with neurostimulator as Franco and Winnie28 do at the moment. Patient is in the prone position, without a pillow under the head or between the scapulas. Identify cricoid cartilage (C6). Ask the patient to rotate the head slightly toward the opposite side and try to touch his/her knee with the hand. The patient should relax the arm and shoulder and lift the head. Both bundles (clavicular and sternal) of the sternocleidomastoid muscle are identified. The soft flesh of the index and major fingers are placed below the clavicular bundle at C6 level. The patient is asked to relax the head. Next, the fingers are slightly rolled from the anterior scalene toward the middle scalene. Do not press hard in this point because it can be unpleasant and/or painful. Descend with fingers leaning on the border of the middle scalene until the beat of the subclavian artery is identified (the lowest possible in the interscalene furrow). Place the index finger on the beat of the artery (Figure 6). Introduce the needle with the shaft as parallel as possible to the skin, in caudal direction. The tip of the needle is directed backwards the beat of the subclavian artery, which is below the index finger of the other hand. Do not go toward medial, following as parallel as possible the same direction as the scalene muscles, which go from the transverse process toward the first rib (Figure 7). Paresthesias of the median nerve are the best (middle trunk), tingling or electric sensation in the index finger.29 With PNS, try to produce a response of the hand, flexion of the fingers and wrist (median) or extension of the fingers (radial) at ⬍0.5 mA and 0.1 msec.
If the pulse of the artery is not palpable in the supraclavicular space, Franco and Winnie suggest that insertion of the needle should be made at a point determined by the transport of the width of the clavicular bundle toward lateral, and a finger slant toward cephalic. Direction of the 22-gauge insulated needle is similar to that of the original technique. ●
25 to 30 mL of LA in the subclavian perivascular fossa produces a motor and sensitive blockade similar to the
The original description of this technique was published in 1979 by Vongvises.31 In 100 cases, he highlighted the easy localization of surface anatomical references and the absence of pneumothorax as the main advantages of this approach. With the purpose of defining the position of the needle in relation to the pleural cupula, this author32 performed a study with tomographic cuts and determined that the level of needle insertion in the parascalene blockade is higher than the level of the pleural cupula (from 0.5 to 1.5 cm). In our country, this approach has been used since the early 1980s by anesthesiologists from the Military Central Hospital,33 and the experience with this approach in 100 patients has been published.34 Its use has also spread in Spain. There, Monzo accumulated great experience with this approach on arthroscopic shoulder surgery.35-37 Dalens describes his experience with the approach by Vongvises. However, he modified its use in children38,39 with PNS. The child is positioned in the supine position, and the puncture site is located in the union of the lower third with the two upper thirds of a line that joins the transverse process of C6 to the midpoint of the clavicle. Except for this difference in the puncture site, the technique is similar to the parascalene approach by Vongvises. This modification is due to anatomical principles because the pleural cupula is at a higher level in children.
Technique ●
●
● ● ●
The patient is in dorsal decubitus without pillows, with the arm to be operated extended at the side of the body, the shoulder downwards, with slight sedation. Anatomical references of the supraclavicular triangle are identified, ie, the posterior border of the sternocleidomastoid muscle, the clavicle, and the anterior border of the trapezius. The patient is asked to slightly rotate the head toward the opposite side. He/she is asked to try to touch his/her knee with the hand, descend the shoulder, and be relaxed. By lifting the head, the two bundles (clavicular and sternal) of the sternocleidomastoid muscle are identified.
102
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006 negative aspiration, the anesthetic solution in increasing fractional volumes of 5 mL. Aspiration among infiltrations is repeated to avoid inadvertent intravenous injection. ●
●
●
Figure 8
Parascalene technique: Patient’s position. ●
●
● ●
● ●
● ●
● ●
●
●
With the soft flesh of the index and major fingers below the clavicular bundle, one palpates the interscalene furrow located outside the posterior border of the sternocleidomastoid muscle. We then descend palpating until the beat of the subclavian artery is found in the vicinities of the clavicle. Certain maneuvers can be performed to make the interscalene space evident. They include: deep inspiration on the part of the patient, lateralization of the head toward the side of the puncture, observation or palpation of the beat of the subclavian artery in the supraclavicular space, etc.40 The key is accurate identification of the lateral border of the anterior scalene. Entrance to the sheath surrounding the plexus can be evident by means of the perception of a click, paresthesia, or motor response to neurostimulation. Skin antisepsis with iodized alcohol or iodopovidone. A dermic wheal is performed with a 25-gauge needle with lidocaine to 1% with 1:200.000 epinephrine in the puncture site, which is 1.5 to 2 cm above the clavicle in the lateral border of the anterior scalene above the subclavian artery and inside the external jugular vein (Figure 8). The authors suggest the use of the neurostimulator with an insulated needle of equal size. We continue using the immobile needle technique with an assistant who carries out the maneuvers with the PNS and injects the anesthetic solution. The needle is inserted in the interscalene groove in anteroposterior direction, ie, the needle tip perpendicularly directed to the plane of the stretcher. Progression is slow until achieving a depth of about 1 to 1.5 cm (Figure 9). In the case of paresthesia technique, the appropriate response must be located either in the shoulder, elbow, or hand. These responses are generally brief, light, and soft. A paresthesia toward posterior (suprascapular) can be elicited; in this case, it is necessary to redirect the needle toward anterior. If the paresthesia is anterior (thorax), the needle should be redirected backwards. If a PNS is available, a motor response is sought in the same areas.
When we obtain contraction of biceps or deltoid muscles with an equal or inferior stimulus than 0.5 mA, a duration of 0.1 msec, and a frequency of 2 Hz, we inject, prior to
If response to PNS is contraction of the diaphragm, we are topographically on the body of the anterior scalene; thus, we should withdraw the needle and reinsert it closer to the median scalene. In general, we obtain a motor response before inserting the needle 1.5 cm deep even in patients with voluminous necks. If the needle goes deeper in, the puncture site should be reconsidered. If the immobile needle technique41 has been adequately followed, we should not worry about the pavilion of the needle coming closer to the tissues since as we apply the injection a supraclavicular “tumor” due to distension of the prevertebral fascia is formed. In the first minutes following injection, tingling or heat sensations appear with impossibility of lifting the arm. A movement such as the one made when “counting money” may also be observed.
Adverse effects and complications Among complications of this approach are: ● ●
Possibility of vascular puncture. Claude Bernard Horner’s syndrome (which predicts success of the blockade). This syndrome disappears when blockade is reverted.
Figure 9
Parascalene technique: Needle direction.
Bollini et al
Figure 10 references.
● ●
●
Supraclavicular Blocks of the Brachial Plexus
Dupre and Danel technique: Anatomical surface
Blockade of the inferior laryngeal nerve with bitonal voice or hoarseness (less frequent). As there are no prospective studies on the incidence of homolateral phrenic nerve paralysis associated with this blockade, we are unable to state whether the incidence is lower than the one associated with the interscalene blockade described by Winnie. Although we consider that the parascalene approach is not ideal for placement of catheters due to perpendicular entrance to the major axis of the plexus, Monzo37 describes placement of catheters for shoulder surgery.
103
Figure 12 Plumb bob: Insertion point is located 1 to 2 cm from the clavicle toward cephalic, tangentially to the lateral border of the sternocleidomastoid muscle.
Cutaneous repairs ● ● ●
Technique ●
●
Supraclavicular technique by Dupré-Danel38 Introduction This technique is also known as “the surface reference” technique. The authors propose a tangential boarding of the plexus that facilitates placement of catheters. Unlike in other techniques, they use an 18-gauge, 5-cm insulated needle and a 20-gauge catheter.
Figure 11
Injection point and direction of the needle.
A: External jugular. B: Apex of Sedillot triangle (it is given by the union of both bundles of the sternocleidomastoid muscle. C: Internal border of the clavicular insertion of the clavicular fasciculus of the trapezius (Figure 10).
● ●
The patient is asked to lift the head from the plane of the stretcher in slight rotation toward the contralateral side to make anatomical references evident. A line is drawn from the cephalic vertex of the Sedillot triangle to the medial border of the clavicular insertion of the trapezius. The itinerary of the external jugular vein is marked (dotted line in Figure 10). The injection point is marked at the intersection of the line of the lateral border of the external jugular vein with the line drawn between the apex of the triangle and the medial insertion of the trapezius in the clavicle. The axis of the puncture goes through the outer ear (Figure 11).
Figure 13 direction.
The needle is advanced in a strict anteroposterior
104
Techniques in Regional Anesthesia and Pain Management, Vol 10, No 3, July 2006 from the approach proposed by Brown is that a lower and more medial puncture site is used, which, from our standpoint, increases the risk of puncture of the pleural cupula.
Intersternocleidomastoid technique Introduction
Figure 14 tion. ●
Intersternocleidomastoid technique: Needle direc-
The usual motor response is that of the triceps. Contraction of the biceps is also an excellent response. The puncture is 1 to 2.5 cm deep, and 30 mL of anesthetic solution is injected. The catheter is 2 cm deep.
In 1997, Pham-Dang13 described a really novel supraclavicular boarding. It was called the intersternocleidomastoid technique, and it was based on a previous anatomical study on cadavers. It stresses the simplicity of the references to keep in mind: the triangle formed by both heads of the sternocleidomastoid muscle and the clavicle, usually visible and palpable in most patients.
Technique ●
●
Plumb-bob technique ●
Introduction This technique was described by Brown.42,43 It shares the position, indications, and volume of local anesthetics with the parascalene technique. The only difference is given by the entrance point of the needle.
Technique ●
●
● ●
●
The lateral border of the sternocleidomastoid muscle should be identified at the level of its insertion in the clavicle. This becomes evident by asking the patient to lift the head from the bed. A 5- to 6-cm blunt needle is inserted in an exact perpendicular and parasagittal plane to the patient and the stretcher (the horizontal one). The insertion point is located 1 to 2 cm from the clavicle toward cephalic, tangentially to the lateral border of the sternocleidomastoid muscle (Figure 12). The needle is advanced in a strict anteroposterior direction (Figure 13). If no contact is made with the first rib or if a paresthesia is not elicited, direction of the needle tip should be modified toward cephalic until a maximum 30° angle is achieved. If paresthesia is not obtained, the needle is redirected toward the feet up to a maximum 30° angle, until either a paresthesia is elicited or the first rib is found.44 The possibility of a pneumothorax increases in this last maneuver if performed by nonskilled hands. With regard to the classic description by Vongvises,31 the only similarity is the anteroposterior (perpendicular to the stretcher) direction of the needle. The difference
●
● ●
● ●
The patient rests in the supine position with the head rotated contralateral to the site of the blockade and with the arm at the side of the body. The triangle formed by both bundles of the sternocleidomastoid muscles and the clavicle is identified. The midpoint is marked. The puncture site is located in the internal border of the clavicular bundle, at two finger’s slant (3 cm) above the sternum. The neurostimulation needle is directed toward caudal, dorsal, and laterally to the midpoint of the clavicle, going below the muscular stomach of the sternocleidomastoid muscle, forming a 40° to 50° angle with the operating table (Figure 14). The plexus is located at a depth of 5 to 7 cm. The muscular responses obtained are those of the radial and musculocutaneous nerves. The latter is the most frequent initial response. 30 mL of LA is injected when the intensity is of 0.5 mA. If the phrenic nerve is stimulated (which is evident by contractions of the diaphragm), the needle is slightly redirected toward lateral.
Although we lack experience with this approach, we should highlight the potentiality of lesions either of the phrenic nerve or of the large vessels of the neck (internal jugular, carotid). In our opinion, this technique does not have outstanding advantages over other approaches.
References 1. Kulenkampff D: Die Anästhesierung des plexus brachialis. Beitr Klin Chir 79:550-552, 1912 2. Lanz E, Theiss D, Jankovic D: The extent of blockade following various techniques plexus block. Anesth Analg 62:55-58, 1983 3. Dupré LJ: Blocking of the brachial plexus: which techniques should be chosen? Cahiers d’Anestesiologie 43:587-600, 1995 4. Pande R, Pande M, Bhadani U, et al: Supraclavicular brachial plexus block as a sole anesthetic technique in children: an analysis of 200 cases. Anesthesia 55:798-802, 2000
Bollini et al
Supraclavicular Blocks of the Brachial Plexus
5. Mak PH, Irwin MG, Ooi CG, et al: Incidence of diaphragmatic paralysis following supraclavicular brachial plexus block and its effect on pulmonary function. Anesthesia 56:352-356, 2001 6. Winnie A, Collins V: The subclavian Perivascular technique of brachial plexus anesthesia. Anesthesiology 25:353-363, 1964 7. Vongvises P, Panijayanond T: A parascalene technique of brachial plexus anesthesia. Anesth Analg 58:267-273, 1979 8. Dupré JL, Danel V, Legrand JJ, et al: Surface landmarks for supraclavicular block of the brachial plexus. Anesth Analg 61:28-31, 1982 9. Brown DL, Bridenbaugh LD: Physics applied to regional anesthesia results in an improved supraclavicular block: the “plumb bob” technique. Anesthesiology 69:A376, 1988 10. Moorthy SS, Schmidt SL, Dierdorf SF: A supraclavicular lateral paravascular approach for brachial plexus regional anesthesia. Anesth Analg 72:241-244, 1991 11. Pippa P, Cominelli E, Marinelli C, et al: Brachial plexus block using the posterior approach. Eur J Anaesthesiol 7:411-420, 1990 12. Ortells-Polo MA, García-Guiral M, García-Amigueti FJ, et al: Anestesia del plexo braquial: resultados de una técnica supraclavicular perivascular modificada. Rev Esp Anestesiol Reanim 43:94-98, 1996 13. Pham-Dang C, Gunst JP, Gouin F, et al: A novel supraclavicular approach to brachial plexus block. Anesth Analg 85:111-116, 1997 14. Winnie AP: Anestesia de Plexos Técnicas Perivasculares de bloqueo del Plexo Braquialqq. Salvat, Barcelona, Salvat, 1986, pp 68-75 15. Winnie AP, Franco CD: Supraclavicular approaches to brachial plexus anesthesia. Tech Reg Anesth Pain Manage 1:144-150, 1986 16. Bollini CA, Urmey W, Vascello L, et al: Relationship between evoked motor response and sensory paresthesia in interscalene brachial plexus block. Reg Anesth Pain Med 28:384-388, 2003 17. Cousins MJ, Bridenbaugh PO: Neural blockade in clinical anesthesia and management of pain, second edition. Philadelphia, PA, J.B. Lippincott Company, 1988, pp 387-417 18. Neal JM, Hebe JR, Gerancher J, et al: Brachial plexus anesthesia essentials of our current understanding. Reg Anesth Pain Med 27:402428, 2002 19. Peláez X, Ornaque I: Bloqueo supraclavicular, in Anestesia Regional Hoy (2° Edición). Capitulo 17:265-280, 2001 20. Brown DL, Cahill DR, Bridenbaugh D: Supraclavicular nerve block: anatomic analysis of a method to prevent pneumothorax. Anesth Analg 76:530-534, 1993 21. Bollini CA: Actas de V congreso Sudamericano y XXVII Congreso Argentino de Anestesiología, Iguazú Misiones, pp 171 y col, 1998 22. Hadzic A, Vloka JD: Peripheral Nerve Blocks Principles and Practice, New York, NY, McGraw Hill, 2004, pp 108-122 23. Jack NTM, Stienstra R: Anesthesie van de plexus brachialis: ervaringen met de posterieure benadering. Ned T Anesthesiol 11:50-52, 1998 24. Rettig HC, Gielen MJ, Jack NT, et al: A comparison of the lateral and posterior approach for brachial plexus block. Reg Anesth Pain Med 3:119-126, 2006
105 25. Neal JM, Hebl JR, Gerancher JC, et al: Brachial plexus anesthesia: essentials of our current understanding. Reg Anesth Pain Med 27:402428, 2002 26. Dagli G, Guzeldemir ME, Volkan Acar H, et al: The effects and side effects of interscalene brachial plexus block by posterior approach. Reg Anesth Pain Med 23:87-91, 1998 27. Rucci FS, et al: How many interscalene blocks are there? A comparison between the lateral and posterior approach. Eur J Anaesthesiol 10:303-307, 1993 28. Franco C, Winnie A: Subclavian perivascular block with a nerve stimulator: outcome study after 1000 blocks. RAPM 24, 1999 29. Hickey R, Garland TA, Ramamurthy S: Subclavian perivascular block: influence of location of paresthesia. Anesth Analg 68:767-771, 1989 30. Wikinski J, Bollini C: Complicaciones neurológicas de la anestesia regional periférica y central. Panamericana. 51-53, 1999 31. Vongvises P, Panijayanond T: A parascalene technique of brachial plexus anesthesia. Anesth Analg 58:267-273, 1979 32. Vongvises P: Beokhaimook Computed tomographic study of parascalene block. Anesth Analg 842:379, 1997 33. Fernandez RO, Sanchez WJ: Nuestra experiencia con una nueva técnica de bloqueo del plexo braquial paraescalénica. Prensa Med Argent 69:890, 1982 34. Salgueiro C, de la Peña R: Experiencia clínica con el abordaje paraescalénico para el bloqueo del plexo braquial Indicaciones, ventajas y complicaciones. Rev Arg Anest 54:322-327, 1996 35. Monzó E, Baeza C, Sánchez ML, et al: Bloqueo paraescalénico continuo en la cirugía del hombro. Rev Esp Anestesiol Reanim 45:377383, 1998 36. Call Reigl L, de Vicente Sole J, Estany Raluy E: Parascalene block for shoulder arthroscopy surgery. Rev Esp Anestesiol Reanim 51:247252, 2004 37. Monzo Abad E, Baeza Gil C, Galindo Sanchez F, et al: Parascalene brachial plexus block: experience of 10 years. Rev Esp Anestesiol Reanim 512:61-69, 2004 38. Dupré JL, Danel V, Legrand JJ, et al: Surface landmarks for supraclavicular block of the brachial plexus. Anesth Analg 61:28, 1982 39. Dalens B, Vanneuville G, Tanguy A: A new parascalene approach to the brachial plexus in children: comparison with the supraclavicular approach. Anesth Analg 66:1264-1271, 1987 40. Bollini CA: Una Maniobra útil para identificar el espacio interescalénico. Rev Arg Anest 55:310-312, 1997 41. Winnie AP: An immobile needle for nerve blocks. Anesthesiology 31:577, 1969 42. Brown DL: Regional Anesthesia and Analgesia. Philadelphia, PA, W.B. Saunders Company, 1996, p 265 43. Brown DL: Atlas of Regional Anesthesia (ed 2). Philadelphia, PA, WB Saunder Company, 1999 44. VadeBoncouer TR, Weinberg GL: Supraclavicular brachial plexus anesthesia using the plumb bob method. Tech Reg Anesth 1:151-156, 1997