Emergency departments accommodate high-acuity patients in complex, high risk environments with high variability in patient flow and resource availability. Strategies for enabling adaptive capacity are necessary for adjusting activities in response to the variability of overall workload and individual patient acuity. This study aims to identify and describe the strategies used by lead-nurses to inform recommendations for training and education. 14 lead-nurses participated in focus group discussions using a table-top sandbox simulation to trigger for reflection on decisions, trade-offs and strategies for handling difficult situations during everyday work. The sandbox simulation was intended to focus the discussions on situation assessment, problem-solving strategies and cognitive challenges. The simulation and following discussions were audio- and video recorded and analysed with reflexive thematic analysis. The results illustrate how lead-nurses work towards maintaining an equilibrium between monitoring and coordinating efforts. This result underlines the complex continuous process of adjusting work and resources to situational conditions and demands. The lead-nurse ' s work is about balancing strategies for monitoring the ED and coordinating care. This balance is important for solving problems here and now while minimising the effects of shifting problems between parts of the ED system or to later points in time. This should be explored further with the question of what strategies that could be standardised versus which should remain adaptive before designing training regimes for adaptive strategies.