Importance: Surgeon stress can influence technical and nontechnical skills, but the consequences for patient outcomes remain unknown.
Objective: To investigate whether surgeon physiological stress, as assessed by sympathovagal balance, is associated with postoperative complications.
Design, setting, and participants: This multicenter prospective cohort study included 14 surgical departments involving 7 specialties within 4 university hospitals in Lyon, France. Exclusion criteria consisted of patient age younger than 18 years, palliative surgery, incomplete operative time-stamping data, procedures with a duration of less than 20 minutes, and invalid surgeon heart rate variability (HRV) data. Data were accrued between November 1, 2020, and December 31, 2021, with 30-day follow-up completed on May 8, 2022. Analyses were performed from January 1 to May 31, 2024.
Exposure: Sympathovagal balance of the attending surgeon in the first 5 minutes of surgery.
Main outcomes and measures: Major surgical complications, extended intensive care unit stay, and mortality within 30 days, after adjustment via mixed-effects multivariable logistic regression for surgeon age, professional status, the time of incision, the random effect of the surgeon, and a composite risk score incorporating patient comorbidities and surgery characteristics. Sympathovagal balance was quantified by the low frequency to high frequency (LF:HF) ratio derived from HRV data measured by chest monitors worn intraoperatively. The LF:HF ratio was normalized at the surgeon level to the median value observed for each surgeon during the study period to control for baseline differences.
Results: A total of 793 surgical procedures performed by 38 attending surgeons were included in the analysis. Median patient age was 62 (IQR, 47-72) years, and 412 (52.0%) were female, with a median of 2 (IQR, 1-4) comorbidities. Median surgeon age was 46 (IQR, 39-52) years, 39 (78.9%) were male, and 22 (57.9%) were professors. Median surgeon heart rate was 88 (IQR, 77-99) beats per minute. Median surgeon LF:HF ratio was 7.16 (IQR, 4.52-10.72) before and 1.00 (IQR, 0.71-1.32) after normalization. Increased surgeon sympathovagal balance during the first 5 minutes of surgery was associated with significantly reduced major surgical complications (adjusted odds ratio [AOR], 0.63; 95% CI, 0.41-0.98; P = .04), though not with reduced intensive care unit stay (AOR, 0.34; 95% CI, 0.11-1.01; P = .05) or mortality (AOR, 0.18; 95% CI, 0.03-1.03; P = .05).
Conclusions and relevance: Increased surgeon stress at the beginning of a procedure was associated with improved clinical patient outcomes. The results are illustrative of the complex relationship between physiological stress and performance, identify a novel association between measurable surgeon human factors and patient outcomes, and may highlight opportunities to improve patient care.