A systematic review of biological changes in surgeons' acute stress levels during surgery.

Background: While a degree of stress facilitates learning and task performance, excessive stress in surgeons may lead to poor patient outcomes, with maladaptive stress as a risk factor for surgeon burnout or self-harm through mechanisms including substance abuse, and suicide. We aim to systematically review publications investigating how measures of surgeons' acute biological stress change during surgery. Methods: Medline, Embase, Cochrane library, and The United States, Australian, and European clinical trials registries were searched using the terms stress; surgeon; cortisol; skin conductance; and heart rate. Studies had to report at least one measure of biological stress related to surgery or simulated surgical exercise and have been published between January 1996 to June 2022. Results: Twenty-eight studies with a total of 433 participants met inclusion criteria with cortisol, heart rate, heart rate variability, and electrodermal activity being reported. Salivary cortisol was measured in four studies with conflicting directional changes reported. Mean heart rate increased in nine studies (by 6-22 beats/minute), however the impact of the physical work of surgery was not reported. Heart rate variability, as measured by low-frequency to high-frequency ratio, was significantly increased in three of six studies. One study measured electrodermal activity reporting significant increase in skin conductance in a simulation setting. Conclusion: While some biological measures appear able to detect changes in acute stress in surgeons (particularly heart rate), appropriate measures of stress during non-stressful and stressful surgery are yet to be fully identified. Importantly, there are no current pathways for identifying surgeons at risk of burnout or self-harm and this is a critical unmet research need.