[Parascalene brachial plexus block: experience of 10 years].
OBJECTIVE: To study the efficacy and complications of a parascalene block over a period of 10 years of experience. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.