Assessment of Stress in Anesthesiologists Using Heart Rate Variability during Anesthetic Induction: An Observational Study

Background: Anesthesiologists often experience work-related stress. No studies have used heart rate variability (HRV), an objective indicator of autonomic nervous system activity, to measure stress in anesthesiologists. Using the maximum entropy method, we measured HRV to assess the degree of stress in anesthesiologists while performing anesthetic induction. Methods: Four anesthesiologists performed several anesthetic inductions while sitting and standing. Precordial electrocardiography was analyzed. The anesthesiologists' heart rate, ultra-short-term entropy, low-and high-frequency components, and normalized unit of the low-frequency component (NU) were measured throughout and during different parts of anesthetic induction. Results: Throughout anesthetic induction, the NU was only parameter that significantly differed between sitting and standing. Two-way repeated ANOVA showed a significant difference only in the average NU between the two groups (P = 0.018 for the average NU, P = 0.088 for the maximum NU). Comparison between the standing and sitting groups showed that the NU was significantly higher during endotracheal intubation in the standing position. During endotracheal intubation, the average NU in the standing group was 87.1% 4.7%, whereas that in the sitting group was 78.1% 8.8% (P = 0.0042). The heart rate was significantly higher during intubation than during preoxygenation while both sitting and standing. Conclusions Anesthesiologists exhibited significantly higher sympathetic tone as measured using HRV during tracheal intubation than during other parts of anesthetic induction. This sympathetic tone was higher while standing than sitting. Sitting during anesthetic procedures might reduce stress in anesthesiologists.