Increase in Operator’s Sympathetic Nerve Activity during Complicated Hepatobiliary Surgery: Evidence for Surgeons’ Mental Stress

Increase in Operator's Sympathetic Nerve Activity during Complicated Hepatobiliary Surgery: Evidence for Surgeons' Mental Stress

KOSHO YAMANOUCHI,¹ NAOMI HAYASHIDA,^1,2 SAYAKA KUBA,¹ CHIKA SAKIMURA,¹ TAMOTSU KUROKI,¹ MICHITA TOGO,³ NORITADA KATAYAMA,³ NOBORU TAKAMURA⁴ and SUSUMU EGUCHI¹

¹Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Nagasaki, Japan
²Division of Strategic Collaborative Research, Center for Promotion of Collaborative Research on Radiation and Environment Health Effects, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Nagasaki, Japan
³Japanese Research Institute of Health Care and Education, Tokyo, Japan
⁴Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Nagasaki, Japan

Surgeons often experience stress during operations. The heart rate variability (HRV) is the variability in the beat-to-beat interval, which has been used as parameters of stress. The purpose of this study was to evaluate mental stress of surgeons before, during and after operations, especially during pancreaticoduodenectomy (PD) and living donor liver transplantation (LDLT). Additionally, the parameters were compared in various procedures during the operations. By frequency domain method using electrocardiograph, we measured the high frequency (HF) component, representing the parasympathetic activity, and the low frequency (LF)/HF ratio, representing the sympathetic activity. In all 5 cases of PD, the surgeon showed significantly lower HF component and higher LF/HF during operation, indicating predominance of sympathetic nervous system and increased stress, than those before the operation (p < 0.01) and these did not return to the baseline level one hour after the operation. Out of the 4 LDLT cases, the value of HF was decreased in two and the LF/HF increased in three cases (p < 0.01) during the operation compared to those before the operation. In all cases, the value of HF was decreased and/or the LF/HF increased significantly during the reconstruction of the vessels or bile ducts than during the removal of the liver. Thus, sympathetic nerve activity increased during hepatobiliary surgery compared with the level before the operation, and various procedures during the operations induced diverse changes in the autonomic nervous activities. The HRV analysis could assess the chronological changes of mental stress by measuring the autonomic nervous balances.

keywords —— autonomic nervous system; heart rate variability; stress; surgeon; surgical operation

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Tohoku J. Exp. Med., 2015, 237, 157-162

Correspondence: Kosho Yamanouchi, M.D., Ph.D., Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, Nagasaki 852-8501, Japan.

e-mail: ymanouch@gk9.so-net.ne.jp