Success of supraclavicular lateral paravascular nerve block based on site of twitch

Abstract

The supraclavicular lateral paravascular approach (SCLP) to brachial plexus anesthesia has been proposed as an effective, safe alternative to the traditional approaches to brachial plexus anesthesia. Successful regional anesthetic technique utilizing a nerve stimulator (NS) and a sheated needle requires a close proximity of the needle to the nerve. The present study is planned to evaluate SCLP blocks performed with a NS by noting whether site of twitch location at a low milliamperage affected success rate. SCLP blocks were performed in 34 patients undergoing minor upper extremity surgical procedures requesting regional anesthesia with a NS. Twitch response in the distribution of the SCLP block was noted and maximized at the lowest mA as possible. No pain or discomfort with surgical incision was considered as successful block. With all twitches obtained at a stimulating current of 0.5 mA or less, an overall success rate of% 88 was achieved. The success rate was increased when twitch response was located distal to the elbow (%96) (forearm, hand, wrist) compared with twitches in the biceps, triceps or elbow (%66). This finding demonstrates a significant increased success rate in distal twitch response (p