The risk of persistent paresthesia is not increased with repeated axillaryblock

Neurologic deficits are noted on physical examination in approximately 0.2% -19% of patients after regional anesthetic techniques. Laboratory and clini cal studies suggest that a subclinical neuropathy occurs much more often. P erforming a regional anesthetic technique during this period may result in additional nerve trauma. We evaluated the frequency of neurologic complicat ions inpatients undergoing repeated axillary block. A total of 1614 blocks were performed on 607 patients. The median number of blocks per patient was two (range 2-10 blocks). The median interval between blocks was 12.6 wk, i ncluding 188 (31%) patients who received multiple blocks within 1 wk. Sixty -two neurologic complications occurred in 51 patients for an overall freque ncy of 8.4%. Of the 62 nerve injuries, 7(11.3%) were related to the anesthe tic technique; the remaining 55 (88.7%) were a result of the surgical proce dure. Patient age and gender, the presence of preexisting neurologic condit ions, a surgical procedure to a nerve, and total number of blocks did not i ncrease the risk of neurologic complications. No regional anesthetic techni que risk factors, including elicitation of a paresthesia, selection of loca l anesthetic, or addition of epinephrine, were identified. The success rate was higher with the paresthesia technique than with nerve stimulator techn ique or transarterial injection, and with use of mepivacaine versus bupivac aine. We conclude that the frequency of neurologic complications in patient s undergoing repeated axillary block is similar to that in patients receivi ng a single regional technique. These patients are not likely to be at incr eased risk of neurologic complications. Implications: The risk of neurologi c complications was not increased in patients who underwent multiple axilla ry blocks, even within a 1-wk interval. No risk factors for anesthetic-rela ted complications were identified. However, block success rate was increase d with the paresthesia technique and the injection of mepivacaine versus bu pivacaine.