[Parascalene brachial plexus block: experience of 10 years]

To study the efficacy and complications of a parascalene block over a period of 10 years of experience.

Since 1993 we have been performing parascalene blocks with 18G, 45 mm needles with 30 degrees bevels using the aponeurotic click method. We administer 30 mL of 1.5% mepivacaine and then insert a flexible catheter into the sheath surrounding the plexus to provide additional doses of 1% mepivacaine to ensure the surgical block of the inferior nerve trunk and/or postoperative analgesia.

The parascalene block technique was used in 2810 patients for shoulder and arm surgery. The block succeeded in 2524 cases (89.82%) and failed in 286 (10.17%). Anesthetic efficacy was excellent in 1921 cases (76.10%), good in 289 cases (11.45%), and insufficient in 312 (12.36%). The most common complications were Bernard-Horner syndrome (71.31%), and ipsilateral hemidiaphragm paralysis (95.72%). Vasovagal events presented in 92 (4.65%) of the shoulder operations in semi-recumbent position. No cases of pneumothorax, respiratory insufficiency, arterial puncture, neuroaxial anesthesia, or medullary or radicular lesion occurred.

The parascalene block is a simple, safe, and effective technique. The probability of serious complications is lower than with most known supraclavicular techniques, mainly because the puncture is perpendicular to the horizontal plane. A neurostimulator or aponeurotic click technique is used and the nerve trunks can be found between 1,5 and 2 cm deep when the plexus is located in reference to the transverse processes.