Study Objective. Our objectives were to estimate the incidence of symptoms of peripheral nerve injury (sPNI) in thoracic surgical patients undergoing video-assisted thoracic surgery or open thoracotomy and to determine whether intraoperative somatosensory evoked potentials (SSEPs) waveform changes correlate with postoperative peripheral neuropathic symptoms. Methods. We conducted a prospective observational study in the operating room of a tertiary hospital. We measured SSEPs intraoperatively and assessed patients for sPNI postoperatively. Results. Forty-four patients consented. Six were excluded from analysis. We found that 42% (95% confidence interval [CI] = 26% to 57%) of patients undergoing thoracic surgery had significant changes in SSEP amplitude and latency. Furthermore, 16% (95% CI = 4% to 28%) of patients had new postoperative symptoms of sensory or motor deficits in an upper extremity. We calculated a sensitivity of 66.7% (95% CI = 29.0% to 100%) and a specificity of 50% (95% CI = 33% to 67.3%) for the identification of sPNI based on automated intraoperative SSEP changes. Conclusions. We identified the incidence of SSEP changes in thoracic surgery (42%) and the incidence of postoperative sPNI after thoracic surgery (16%). We identified a positive correlation between intraoperative SSEP changes and postoperative sPNI, which after multivariate analysis was not significant given the small sample size of the study. By the time sensory and/or motor changes are detected postoperatively, it may be too late to reverse the nerve damage. Future versions of the EPAD device could provide anesthesiologists a way to monitor for the development of sPNI, and make changes before a potential injury becomes permanent.
Keywords: Intraoperative Assessment; Point of Care Monitoring; nerve damage; neurological monitoring; thoracic surgery.