The Supraclavicular Block

Introduction:

• Provides anesthesia of the brachial plexus at the level of the divisions, resulting in little, if any, sparing of the peripheral nerves

Indication 

• Surgery on the upper extremity, including (but not limited to) shoulder, elbow, and hand

Set-Up:        

• Betadine skin prep
• Nerve stimulator
• Ultrasound machine with appropriate probe (5-12 MHz probe)

• 22 gauge insulated needle (a 2-inch needle will be adequate ultrasound-guided technique, a 4-inch needle will be adequate for the traditional technique)

• local anesthetic:

• intermediate duration: 40-60 mL 1.5% (600- 900 mg) mepivacaine with epinephrine 1/200,000 (optional: HCO3- 0.1 mEq/mL)
• long duration: substitute 10mL of the mepivacaine solution with 0.75% (75 mg) bupivacaine with epinephrine 1/200,000

Anatomy:       

• The nerves surround the subclavian artery at the level of the first rib

Technique:
            Traditional: 

• Identify the midpoint of the clavicle, and palpate the interscalene groove; this may be accomplished by discerning the lateral border of the sternocleidomastoid muscle, and then palpating the body of the anterior scalene muscle. 
• Insert the needle 1.5 to 2 centimeters posterior to the midpoint of the clavicle in a caudad orientation in a slightly medial and posterior direction 
• Set the nerve stimulator to 1.0 Amp, and paresthesia or motor response is sought; once the desired motor response is obtained, maximize the twitch amplitude  by manipulating the needle with
  small movements while reducing the current to < 0.5 mAmp  
• If the first rib is encountered with no paresthsia or motor response, the needle is directed along the rib either posteriorly or anteriorly until the desired response is achieved.  

           

Ultrasound Guided:

• Hold the ultrasound probe in your non-dominant hand and visualize the subclavian artery, beginning superior and posterior to the clavicle and  aiming caudad
• The nerve bundle will be immediately superior and posterior to the artery and superior to the first rib, appearing as 3-4 round dark circles, often touching the artery. (to confirm, the nerve bundle can be followed cephalad into the interscalene groove, becoming a vertical series of dark circles)
• Introduce the needle transversely to the plane of the ultrasound probe from the distal side of the probe, allowing the needle to advance in small increments towards the nerve bundle (a nerve stimulator may be used in addition to ultrasound to confirm correct location)
• Directly visualize the local anesthetic surrounding the nerve bundle; 45 to 55 mL of local anesthetic is injected in 5 mL increments with gentle aspiration between doses

Limitations:

• Contralateral pneumothorax
• Patient refusal
• Bleeding diasthesis
• Infection at the site of needle insertion

Complications:   

• Pneumothorax
• Hematoma
• Intravascular injection
• Neuropraxia and neurologic injury (rare)

Notes:

• Can be used for patients with COPD (rare to cause phrenic nerve paralysis)
• Can be performed with patient’s arm in any position
• To find the needle on ultrasound, make certain that the planes of needle and probe and intersect below the skin; an alternative strategy is to inject a 1-2 mL and watch the display to see where the solution is located (indicating the end of the needle)
• Do not inject against a lot of resistance, withdraw the needle 1 mm and attempt again

 

References:

1. Chan, V, Perlas, A, Rawson, R, Odukoya, O. “Ultrasound Guided Supraclavicular Brachial Plexus Block.” Anesth Analg 97: 1514-1517 (2003).
2. Franco, C, Domashevich, V, Voronov, G, Rafizad, A, Jelev, T. “The Supraclavicular Block with a Nerve Stimulator: To Decrease or Not Decrease, That is the Questions.” Anesth Analg 98: 1167-1171 (2004) .
3. Klaastad, O, VadeBoncouer, T, Tillung, T, Smedby, O. “An Evaluation of the Supraclavicular Plumb-Bob Technique for Brachial Plexus Block by Magnetic Resonance Imaging.” Anesth Analg 96: 862-867 (2003).
4. Miller, Ronald. Miller’s Anesthesia. Churchill Livingstone (2005).
5. Neal, J, Moore, J, Kopacz, D, Liu, S, Kramer, D, Plorde, J. “Quantitative Analysis of Respiratory, Motor, and Sensory Function After Supraclavicular Block.” Anesth Analg 86: 1239-1244 (1998).

 

Joshua D. Goldstein MD
2007-2008 Regional Anesthesia Fellow

 

 

These technique descriptions are presented for educational purposes and are not intended to substitute for actual hands-on training.