The Effect of Paresthetic Location on the Distribution in Brachial Plexus Block by Supraclavicuar Perivascular Approach

Lee, Hye Won; Chae, Byung Kook; Shin, Jung Soon

Abstract

The continuous perineural, perivascular compartment surrounding the brachial plexus from the tip of the cervical transverse process to the axilla may be entered at virtually any level, and the extent of anesthesia depends upon the level of entry and volume of local anesthetics injected. Various approaches of brachial plexus block were introduced to produce a successful block with the least complications. In this study, 25 ml of 0.5% bupivacaine hydrochloride solution was injected by subclavian perivasular approach to illustrate the effect of various locations of paresthesia on the distribution of analgesia in 50 patients who had an operation of the hand or forearm. The location of paresthesia evoked by insertion of a 23-gauge scalp needle during performance of brachial plexus block was checked at the distribution of the superior, middle, and inferior trunks. A pin prick test was performed at 15 min, 30 min and 45 min after injection of bupivacaine hydrochloride to evaluate the distribution of analgesia in the superior, middle and inferior trunk of the brachial plexus. The incidence of analgesia in all three trunks was the highest when paresthesia of the middle trunk distribution was elicited. The incidence of analgesia in the superior trunk distribution was significantly lower when inferior trunk paresthesia was elicited than when superior trunk paresthesia was elicited. Superior trunk paresthesia was the most frequently elicited. Complications were arterial puncture (32%), Horner's syndrome (8%) and hematoma (2%). The results indicates that brachial plexus block by supraclavicular subclavian perivascular approach is a relatively safe technique. Injection of local anesthetics following the confirmation of middle trunk paresthesia is desirable to obtain the successful block. Especially when analgesia of superior trunk distribution is required, the direction of needle insertion should be adjusted to avoid the inferior trunk paresthesia elicited.