Intraoperative real-time stress in degenerative lumbar spine surgery: simultaneous analysis of electroencephalography signals and heart rate variability: a pilot study

BACKGROUND CONTEXT: Interest in intraoperative stress has increased due to its potentially detrimental impact on surgical performance and burnout among spine surgeons. PURPOSE: The purpose of this study was to analyze intraoperative stress in real time in terms of electroencephalography signals and heart rate variability using a wearable device during spine surgery. STUDY DESIGN: Prospective observational study. PATIENT SAMPLE: Five orthopedic spine surgeons with experience ranging from 1 to 30 years were included. OUTCOME MEASURES: The outcome measures included stress levels among the spine surgeons and differences in stress parameters between novice and expert surgeons and between assistants and operators. METHODS: From June 2018 to November 2018, 179 consecutive records of intraoperative stress measures, including intraoperative electroencephalography signals and heart rate variability, comprising beats per minute (BPM) and low frequency/high frequency ratio, for the orthopedic spine surgeons were prospectively gathered, compared, and analyzed. RESULTS: Among all measures, sensory-motor rhythm (SMR) waves, gamma waves, and BPM differed significantly during surgery (analysis of variance; p=.040, .013, .002, respectively). Surgery duration and intraoperative bleeding were positively correlated with stress parameters, including gamma waves and tension. For operators, surgeon experience was negatively correlated with concentration, tension, and SMR, gamma, M-beta, and H-beta waves (Pearson correlation, p<.05). However, for assistants, surgeon experience was positively correlated with concentration, tension, BPM, and SMR, M-beta, H-beta, and gamma waves. Bleeding amounts were correlated positively with gamma waves and tension for both operators and assistants (Pearson correlation, p<.05). Stress among operators was higher than that among assistants in terms of low frequency/high frequency ratio. CONCLUSIONS: Operators and surgeons with low experience exhibited higher stress levels during surgery, which should be addressed when scheduling elective surgery to ensure optimal conditions among spine surgeons.