Transarterial techniques are not effective for subclavian perivascular block.

Abstract

Although transarterial techniques have been commonly used for axillary block, results with these techniques have not been previously described for subclavian perivascular block. We studied the efficacy and complications of two types of arterial techniques for subclavian perivascular block. In Group 1 (n = 10), the subclavian perivascular injection was made after withdrawing the needle from the subclavian artery (top of artery), and in Group 2 (n = 8), the injection was made after advancing through the subclavian artery (bottom of artery). The local anesthetic used was lidocaine 1.5% with epinephrine 1:200,000 in a volume determined by the formula [ml = (height in inches divided by 2) + 5]. Both techniques were associated with a low incidence (50% or less) of anesthesia throughout the brachial plexus dermatomes. Sixty percent of patients in Group 1 and 63% of patients in Group 2 required supplemental blocks. In view of the low incidence of anesthesia and the frequent need for supplementation, additional patients were not enrolled in the study. Complications associated with the technique included hematoma (12-20%), recurrent laryngeal nerve block (10-25%), Horner's syndrome (0-20%) and phrenic nerve block (75-80%). Despite the relatively high dose of lidocaine used, serum lidocaine levels remained well below the toxic range.