Brief Reports: Nerve Stimulator Evoked Motor Response Predicting a Successful Supraclavicular Brachial Plexus Block

BACKGROUND:

We examined the success rate of supraclavicular brachial plexus block after the different evoked motor responses to nerve stimulation.

METHODS:

This multicenter observational study included 377 patients. For each block, the evoked motor response elicited at 0.25 mA for 2 milliseconds was recorded, 30 mL bupivacaine 0.25% was injected, and the block was observed for success or failure.

RESULTS:

Complete anesthesia occurred in 317 cases (84.1%). The success rate was 100% when the evoked motor response was simultaneous flexion of the third and fourth digits or flexion of all 4 digits (digits 2–5) with or without thumb opposition.

CONCLUSION:

Simultaneous flexion of the third and fourth digits with or without other digits is associated with the highest success rate of supraclavicular brachial plexus block.