Clinical Research Directory

Perfusion Index in Monitoring Recovery From Brachial Plexus Block After Forearm Surgery

Postoperative differentiation between residual regional anesthetic effect and other causes of persistent sensory or motor deficit is a common clinical problem after peripheral nerve blocks. Perfusion index (PI), a noninvasive pulse oximetry-derived measure of peripheral perfusion, rises after sympathetic blockade and has been studied for predicting block success and duration. However, its ability to detect the resolution of a block has not been established. This prospective observational study will evaluate the diagnostic accuracy of the PI ratio between the blocked and contralateral hand for detecting sensory and motor block resolution in adult patients undergoing elective forearm surgery under ultrasound-guided infraclavicular brachial plexus block. PI, sensory block (pinprick), and motor block will be assessed repeatedly from before the block until 24 hours postoperatively. Cut-off values of the PI ratio for the first regression and the complete resolution of sensory and motor block will be determined using ROC analysis.