High fidelity simulated environment allowed safe learning of critical events and knowledge of appropriate response and treatment. Anesthesiology resident education curriculum in Lyon plans several high fidelity simulation session with a large panel of critical events. Anticipation of critical events before they may occur, plannification of team resources, priority in the treatment strategy and effective communication within the team, may help to improve team performance during the scenario. The investigators' goal is to compare team performance during the scenario with or without a preparation team staff of 4 min. This staff will be suggested after the briefing of the scenario but before the scenario starts. The investigators are going to compare groups of anesthesiology residents going through same scenarios of simulated critical events in high fidelity simulation session. Scenarios will be recorded to be analyzed by 2 reviewers independantly. A checklist of appropriate treatment and a non technical skill checklist will be use to cote team performance. Stress of the participants will be assessed by visual analogic scale of participants anxiety and stress. the two groups (preparation staff or no preparation staff) will be compare to see if improvement in team performance is associated with the intervention.