The harmful effects of stress on health professionals are expressed both in terms of their health (physical or mental) and the quality of work (reduced memory capacity, deterioration in patient care). These adverse effects highlight the importance of implementing effective coping strategies and/or early learning of stress management methods in medical training programs.

Relaxation breathing techniques coupled with heart rate variability (HRV) biofeedback is one of the new techniques used to reduce the stress level.

No research has yet tested the effects of HRV induced by relaxation breathing technique before managing a simulated critical situation.

This is a randomized, controlled study conducted at the university simulation centre in healthcare of Lyon, France. The high-fidelity simulation (HFS) will be used as a research tool and the topics included will be the HFS residents summoned to critical care situations as part of their training curriculum. The study has received prior approval from the UCBL1. Ethics Committee. After information (protocol and objective of the study), signature of consent, and one minute of relaxing breathing training, the residents as active participants in HFS, will be included in the study. They will be equipped with Hexoskin® jackets collecting heart rate, heart rate variability, breathing rate continuously and an Empathica® connected watch for continuous measurement of electrodermal activity. Then each resident will be randomized into one of the three intervention groups that are:

• a relaxing breathing exercise coupled with biofeedback
• a breathing exercise without biofeedback
• a control occupation (observation of normal biological results). Each intervention will last five minutes and will be conducted between the briefing and the scenario.

Main objective :

The objective of this study is to compare during HFS, the performance of residents during critical care scenarios. The performance analysis will be performed by two independent and blinded evaluators, based on the video recordings of scenarios. The overall performance will be the addition of technical skills (specific rating grid for each scenario on 100 pts) and non-technical skills assessed by the OTTAWA GRS grid (adjusted to 100 pts).

Secondary objectives :

• Compare the effects of the three interventions on reducing psychological stress.
• Compare the effects of the three interventions on reducing physiological stress.
• Compare the effects of the three interventions on increasing cardiac coherence scores.

Inclusion Criteria:

• Adult person
• Registered in specialized diploma of medical training.
• Invited for a high-fidelity simulation session at the Lyon university simulation center.
• Have signed an informed consent form.

Exclusion Criteria:

• pregnant woman

Intervention will not be observed by outcomes assessor Performance will be evaluated on video recording after the simulation