A novel approach of using brachial plexus blockade as an experimental model for diagnosis of intraoperative nerve dysfunction with somatosensory evoked potentials: a blinded proof-of-concept study

Intraoperative nerve dysfunction has been difficult to investigate because of its rarity and unpredictable occurrence. The diagnostic test attributes function monitors have not clearly defined. This proof-of-concept study aimed assess the feasibility using brachial plexus blockade (BPB) in awake patients as an experimental model for characterize somatosensory evoked potentials (SSEPs). We obtained baseline SSEPs neurologic subsequently placed BPBs (experimental model) generate progressive states dysfunction. monitored SSEP changes (index test) symptoms (reference standard) simultaneously during onset BPB determine temporal relationships SSEPs. Brachial produced differential motor sensory that allowed simultaneous clinical neurophysiologic assessment. One hundred fifty-seven pairs multiple data points from 14 were included final analysis. abnormal signals almost always preceded symptoms. sensitivities specificities detect impairment power (motor rating score ≤ 4/5), cold sensation, two-point discrimination 100% 67%, 99% 55%, 46%, respectively. found can produce sufficient allow adequate evaluation a monitor. results this may stimulate further work on refining intraoperative models monitors. www.clinicaltrials.gov (NCT03409536); registered 24 January 2018.